Attention Deficit Hyperactivity Disorder

Edited by Shane R. Jimerson, Ph.D.
Contributed to by the Graduate Students in the Counseling, Clinical, and School Psychology Program at the University of California, Santa Barbara.

Ongoing design and publication of this site is completed by Shane R. Jimerson, Jeff R. Klein and Angela D. Whipple.  Please forward comments regarding this site to Shane R. Jimerson.  This page was last updated 1.11.02.  © 2002

Symptoms
Epidemiology
Etiology
Assessment
Treatment
 

Authors
Shane R. Jimerson, Berkley Bowers, & Gabrielle Anderson
University of California, Santa Barbara

The authors also note the important contributions of Barbara D’Incau, Robert Ngan and Sabrina Rhee, who provided information critical to the development of this website.

Attention Deficit Hyperactivity Disorder

     Attention Deficit Hyperactivity Disorder (ADHD) is the most commonly diagnosed behavioral disorders during childhood (Tannock & Schachar, 1996; Shaywitz, Fletcher & Shaywitz, 1994; Shelton & Barkley, 1994; Kavanagh & Lyon, 1994; Barkley, 1990b).  ADHD includes a heterogeneous array of symptoms which overlaps markedly with oppositional defiant disorder, conduct disorder, affective disorders such as depression, anxiety, learning disabilities, and communication disorders.  The most common age for diagnosis is between the ages of 7 and 9, although symptoms may be apparent before the age of 3 (Cohen et. al., 1993).  According to DSM-IV-TR criteria, the onset of ADHD is before age 7, however, many individuals are not diagnosed until a later age due to the prominent expression of ADHD symptoms in the school setting. ADHD is characterized by a persistent pattern of behavioral symptoms of inattention, hyperactivity, and impulsivity (APA, 2000; Barkley, 1990a, 1990b).  Children showing behaviors that are characteristics of ADHD have been found to be highly “at-risk” for maladaptive educational and social outcomes.  Furthermore, although a child may not meet full DSM-IV criteria for ADHD, subclinical problems of inattention, impulsivity or hyperactivity may contribute to deleterious outcomes such as low reading achievement (Warner-Rogers, Taylor, Taylor & Sandberg, 2000).  It is important for the school psychologist or child clinician to provide accurate information about ADHD to children and their parents as misperceptions about the disorder, such that it is primarily a disorder of inattention or that that the ADHD child must display symptoms of both inattention and hyperactivity are common.  Controversial debates continue with regards to etiology, diagnosis and the use of pharmacological intervention for ADHD.
 
 

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DSM-IV-TR Criteria for ADHD

Source:
The Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition, Text Revision (APA, 2000) lists diagnostic criteria for Attention-Deficit/Hyperactivity Disorder (p. 85-93):

A. Either (1) or (2):

(1) six (or more) of the following symptoms of inattention have persisted for at least 6 months to a degree that is maladaptive and inconsistent with developmental level:

Inattention
(a) often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities
(b) often has difficulty sustaining attention in tasks or play activities
(c) often does not seem to listen when spoken to directly
(d) often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions)
(e) often has difficulty organizing tasks and activities
(f) often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (such as schoolwork or homework)
(g) often loses things necessary for tasks or activities (e.g., toys, school assignments, pencils, books, or tools)
(h) is often easily distracted by extraneous stimuli
(I) is often forgetful in daily activities

(2) six (or more) of the following symptoms of hyperactivity-impulsivity have persisted for at least 6 months to a degree that is maladaptive and inconsistent with developmental level:

 Hyperactivity
(a) often fidgets with hands or feet or squirms in seat
(b) often leaves seat in classroom or in other situations in which remaining seated is expected
(c) often runs about or climbs excessively in situations in which it is inappropriate (in
adolescents or adults, may be limited to subjective feelings of restlessness)
(d) often has difficulty paying or engaging in leisure activities quietly
(e) is often “on the go” or often acts as if “driven by a motor”
(f) often talks excessively

Impulsivity
(g) often blurts out answers before questions have been completed
(h) often has difficulty awaiting turn
(i) often interrupts or intrudes on others (e.g., butts into conversations or games)

B. Some hyperactive-impulsive or inattentive symptoms that caused impairment were present before age 7 years.

C. Some impairment from the symptoms is present in two or more settings (e.g., at school and at home).

D. There must be clear evidence of clinically significant impairment in social, academic, or occupational functioning.

E. The symptoms do not occur exclusively during the course of a Pervasive Developmental Disorder, Schizophrenia, or other Psychotic Disorder and are not better accounted for by another mental disorder (e.g., Mood Disorder, Anxiety Disorder, Dissociative Disorder, or a Personality Disorder).

Subtypes

Attention-Deficit/ Hyperactivity Disorder, Combined Type:
This subtype should be used if six or more symptoms of inattention and six or more symptoms of hyperactivity-impulsivity have persisted for at least 6 months to a degree that is maladaptive and inconsistent with developmental level.  Most children and adolescents with the disorder have the Combined Type.  It is not known whether the same is true for adults with the disorder.

Attention-Deficit/Hyperactivity Disorder, Predominantly Inattentive Type:
This subtype should be used if six or more symptoms of inattention (but fewer than six symptoms of hyperactivity-impulsivity) have persisted for at least 6 months to a degree that is maladaptive and inconsistent with developmental level.  Hyperactivity may still be a significant clinical feature in many such cases, whereas other cases are more purely inattentive.

Attention-Deficit/Hyperactivity Disorder, Predominantly Hyperactive-Impulsive Type:
This subtype should be used if six or more symptoms of hyperactivity-impulsivity (but fewer than six symptoms of inattention) have persisted for at least 6 months to a degree that is maladaptive and inconsistent with developmental level.  Inattention may often still be a significant clinical feature in such cases.

Attention-Deficit/Hyperactivity Disorder Not Otherwise Specified:

This category is for disorders with prominent symptoms of inattention or hyperactivity-impulsivity that do not meet the criteria for Attention-Deficit/Hyperactivity Disorder.  Examples include:
1. Individuals whose symptoms and impairment meet the criteria for Attention-Deficit/Hyperactivity Disorder, Predominantly Inattentive Type but whose age of onset is 7 years or after.
2. Individuals with clinically significant impairment who present with inattention and whose symptom pattern does not meet the full criteria for the disorder but have a behavioral pattern marked by sluggishness, daydreaming, and hypoactivity.
 
 

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EPIDEMIOLOGY

     Attention deficit hyperactivity disorder is the most commonly diagnosed behavioral disorder of childhood, estimated to affect 3 to 7 percent of school-age children (American Psychiatric Association 2000; National Institute of Health, 1998).  Increases in identification during the school-age years may be a factor of the school environment rather than increases in the actual incidences.  More specifically, behavioral symptoms of ADHD (i.e., easily distracted, difficulty sustaining attention in tasks) are more often observed in classroom settings where formal structure is warranted.  Thus, children are more likely to be referred for an ADHD diagnosis during the school-age years rather than the pre-school years when certain behavioral norms are expected in the elementary classroom.  More often than not, symptoms of this disorder are evident beginning in early childhood and extend into adulthood.  Indeed, it has been reported that 50 percent of children diagnosed with ADHD as preschoolers will either receive a similar diagnosis at a later age (Campbell, 1990) and/or continue to exhibit symptoms of this disorder into adulthood (Barkley, Fischer et.al., 1990; Gittelman et.al., 1985; Weiss & Hechtman, 1993). Developmentally the symptoms of ADHD typically attenuate or change in form as one matures and grows older, though the severity and extensity of problems may remain (American Psychiatric Association, 2000; Whalen & Henker, 1998).
     The number of boys diagnosed with ADHD outnumber girls by at least 4 to 1.  The higher ratio of males in clinic samples may be due to selective referral, rather than actual incidence.  Furthermore, females are more likely to exhibit internalizing symptoms that involve mood, affect and emotion, whereas males usually display more externalizing symptoms such as aggressive and antisocial behaviors.  Thus referrals initiated from the school environment are more likely to be due to overt or disruptive behavior, symptoms found more often in males with this disorder.  Children who exhibit the Predominantly Inattentive Type are more likely to be placed in special education classes for students with learning disabilities despite that as a group they do not display significantly greater learning deficits than children with the Combined or Predominantly Hyperactive-Impulsive Types.  Furthermore, children who exhibit the Combined and Hyperactivity-Impulsive Types are more likely to be placed in special education classrooms for children with emotional and behavioral disorders  (Warner-Rogers, Taylor, Taylor, & Sandberg, 2000).
 Warner-Rogers, Taylor, Taylor, and Sandberg (2000) redressed the lack of research focusing specifically on children who exhibit inattentive behavior through an large, community-based epidemiological study of seven year old boys.  Comparisons were made between the developmental functioning, social, and environmental backgrounds of children with pure inattentive behavior to that of children with pure overactive behavior and combined problems of inattentive and overactive behavior.  The authors found that children with pure inattentive behavior were more likely to have general cognitive delays, especially in the area of language development, and were more likely to come from families where the father was of low occupational status.
     This study underscores the importance for educators, clinicians, and researchers to improve identification methods for children displaying the Predominantly Inattentive Type.  Although purely inattentive children did not exhibit the magnitude of disruptive behavior that the purely overactive or Combined Type children did, inattentive behavior was highly associated with adjustment problems in the classroom such as having reading impairments, possessing low self-esteem, and needing directions repeated (Warner-Rogers, Taylor, Taylor & Sandberg, 2000).
     Co-morbidity of ADHD with conduct disorder (50  percent; Biederman et. al., 1991), oppositional-defiant behavior, anxiety disorders, speech and language disorders (78  percent; Baker & Cantwell, 1992), and learning disabilities (LD) (41-70 percent; Holborow & Berry, 1986; Mayes, Calhoun & Crowell, 2000) is extremely high.  Estimates of the incidence of school-age children with partial ADHD syndrome and one or more other problems present (i.e., anxiety, depression, etc.) are 5 to 10 percent (www.chadd.org/facts).  Comorbidity appears to be more common in younger than in older children (Bird et. al., 1993; Russo & Beidel, 1994).
     Mayes, Calhoun, and Crowell (2000) explored the overlap between ADHD and learning disabilities in a clinical sample of 8 to 16 year olds.  The authors found that a LD was present in 70 percent of the children with ADHD.  Furthermore, a LD in written expression was twice as common (65 percent) as a LD in reading, math or spelling.  No previous research studies examining the prevalence of LD in children with ADHD assessed for LD in written expression. Furthermore, children with both a LD and ADHD had more severe learning problems than children who had a LD but not ADHD as well as had more severe attention problems than children with ADHD but not a LD.  Based on their observation that children with ADHD who did not meet full criteria for a LD still experienced learning difficulties, the authors conclude that learning and attention problems are best conceptualized as existing on a continuum where they usually are interrelated and coexist.
     The symptoms of this disorder are closely tied to behavioral difficulties.  And as a result, it has been documented that about 40 percent of referrals to child guidance clinics are associated with children diagnosed with this disorder (Barkley, 1990).  Over 60 percent of adolescents with ADHD have been documented to be defiant in comparison to 11 percent of the non-ADHD population (Barkley, Fischer, Edelbrock & Smallish, 1990).  As adults, it has been estimated that 33 percent will not complete high school, with only 5 percent completing a college degree (Barkley, Fischer, et. al., 1990).  Almost 1 in 4 of these individuals is likely to develop chronic maladaptive patterns such as substance abuse, occupational instability, and interpersonal difficulties (Barkley, Fischer, et. al., 1990).  About one-third of this population is estimated to be resilient, meaning they find adaptive means to cope with the disorder (Barkley, 1990).
     Gingerich, Turnock, Litfin, and Rosen (1998) considered the epidemiology of diverse populations and ADHD.  The authors stress the importance of including diversity variables such as ethnicity, age, gender, and SES in the assessment, diagnosis, and intervention strategies of ADHD.  Cross-cultural comparison of hyperactive behavior must be understood and examined with caution as cultural factors may influence both the demonstration of the disorder as well as the approach to intervention strategies.  These diversity variables may contribute to inappropriate diagnosis as expected behavioral norms may fluctuate in these various groups. A 1999 study in the Journal of the American Academy of Child and Adolescent Psychiatry addressed the gender differences in the diagnosis of ADHD. The authors suggest that the disorder frequently goes undiagnosed in girls because they are less likely to behave disruptively, which is one of the most common signs of the disorder.  The study included 140 girls with ADHD and 122 girls who did not have ADHD, ranging in age from 6 to 18 years old.  Results of this study imply that if the core problem of ADHD is redefined from a behavior disorder to the issue of inattention, then it is likely that the number of girls identified will increase.
     Attention-deficit/hyperactivity disorder is one of the most prevalent childhood disturbances in the United States, affecting upward of 400 million children and adolescents. ADHD has received much publicity in recent years and professionals should clarify misunderstandings when working with children and their families.  Children with ADHD may have pronounced difficulties and impairments resulting from the disorder across multiple settings.  They may also experience long-term adverse effects on academic performance, vocational success, social-emotional development and peer relations.  Males are diagnosed with ADHD at approximately three times the rate of females which may be due the Combined and Predominantly Hyperactive-Impulsive forms of the disorder being more common in males.  There is no conclusive evidence of the causes of this disorder, thus extensive assessment measures should include various settings as well as informants in order to understand the multiple factors that may contribute to the symptoms.  Given the overlap of ADHD with oppositional defiant disorder, conduct disorder, antisocial personality traits, and learning disabilities, psychologists need to assess related domains of functioning when addressing a referral question regarding ADHD.  Subclinical problems such as learning difficulties, hyperactivity, and attention problems should also be addressed when planning treatment interventions. Recent studies reveal that there are wide variations in the diagnosis of the disorder, resulting in under and over identification of ADHD within certain populations, thus environmental and socio-cultural variables need to be considered during assessment of the behavioral symptoms common in ADHD.
 
 

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I.  ETIOLOGY

     The familial incidence of ADHD has long been noted. Early investigations centered around biological hypotheses and “Minimal Brain Dysfunction” was postulated in explaining the origin of the disorder.  Following World War II, pediatricians, neurologists, and child psychiatrists observed that brain-damaged children were often hyperactive, inattentive, had learning difficulties, and displayed a wide variety of behavior problems. This led to the original diagnostic concept of “minimal brain damage.”  However, subsequent large epidemiological studies of grossly brain-damaged children did not support a link with excessive hyperactivity nor did more recent imaging studies find evidence of gross brain damage in ADHD children.
     Over time, the various characteristics including hyperkinesis/hyperactivity, inattention/distractibility, and impulsive responding became the focus of research in etiology, assessment, and treatment.  Whether or not attentional deficits are, in fact, a hallmark of this disorder is currently debated.  The great variability in symptomology, prognosis, and comorbidity has made definite etiologic determinants elusive. As a result, it has captured the interest of clinicians and researchers from many different disciplines.  Currently researchers are also investigating and comparing the etiologies of different ADHD subtypes which indicate that ADHD is a heterogeneous disorder.  Moreover, an understanding of the etiology of ADHD has important implications for treatment procedures.  Current hypotheses involve a complex transactional model which links genetic, biological, familial, cognitive/ neurological, psychosocial, and developmental contributors.  The following sections of this paper will provide information and current research regarding various etiological factors and their associations with ADHD.

Genetic Contributors:

     Research evidence suggests that ADHD is a trait which is highly hereditary in nature, making heredity one of the most well-substantiated etiologies for ADHD (Barkley, 1997).  Consequently genetic research has contributed to these studies in order to explain familiality, heritability, mode of transmission, and gene locations (Tannock, 1998).  Twin studies have provided genetic researchers the opportunity to explore genetic as well as shared and non-shared environmental factors in the identification of ADHD.
     Research has shown that if a parent has ADHD, the risk to the offspring is 57 percent.  As evidenced by recent twin studies, the average heritability is .80 for symptoms of ADHD, suggesting a strong genetic contribution (Barkley, 1997).  Sprich, Biederman, Crawford, Mundy and Faraone (2000) lent additional support to the genetic hypothesis for ADHD etiology through their study examining the rates of ADHD and associated disorders in the first-degree biological relatives of ADHD children and adolescents.  The authors found that 18% of the biological parents of ADHD youths had ADHD compared to 6% of the adoptive parents of ADHD youths and 3% of the biological parents of the non-ADHD control youths.  As the rate of ADHD in adoptive parents of adoptees with ADHD did not differ significantly from the rate found in the biological parents of the control subjects, the researchers conclude that there is no increased risk for ADHD amongst the adoptive parents of adopted ADHD youths.  Furthermore, significantly higher rates of mood and anxiety disorders were found in the biological parents of ADHD youths than in the adoptive parents of ADHD youths.  The authors suggest that these other psychiatric disorders are manifestations of the same genes that influence ADHD rather than parental disorders resulting from the stress of raising a child who has ADHD.
     In a review of molecular genetic studies of AHD, Faraone (2000) proposes that ADHD comprises several disorders having different genetic and nongenetic etiologies rather than a single, unitary disorder.  This proposition is supported by inconsistent results from molecular genetic studies such as those investigating the influence of the dopamine transporter gene (DAT) and the dopamine D4 receptor gene (DRD4) on susceptibility to ADHD (Biederman & Spencer; Faraone, 2000).  Faraone highlights two other clinical features, psychiatric comorbidity and long-term outcome, as evidence for the genetic heterogeneity of ADHD.
Faraone and his colleagues tested competing hypotheses about the comorbidity of ADHD with other disorders and concluded that there appear to be two types of ADHD families.  There are families in which ADHD occurs with bipolar disorder and/or conduct disorder and there are families in which ADHD occurs without bipolar disorder or conduct disorder.  Although ADHD and major depression were found to share common familial vulnerabilities, the researchers were unable to distinguish subforms of ADHD based upon the presence of major depression in the family.  Hence, in contrast to bipolar disorder and conduct disorder, major depression appeared to be a phenotypic rather than a genetic marker of heterogeneity in ADHD.  Anxiety and learning disorders showed weak associations with ADHD in the families of this study.  However, the authors stress the need for more investigation in order to make conclusions about whether these disorders share genetic causes with ADHD.
     As long-term outcome may have further implicates for genetic heterogeneity, Faraone cites evidence for the stronger influence of genes on persistent ADHD than on remitting ADHD.  Faraone, Biederman, and Monuteaux (2000) found that the prevalence of ADHD in parents of youths who continued to meet diagnostic criteria for ADHD in mid-adolescence was 16.3%  compared to a 10.8% prevalence of ADHD  in the parents of youth whose ADHD had remitted by mid-adolescence.  The prevalence in their siblings was 24.4% and 4.6%, respectively.  Faraone (2000) interprets the data as suggesting that children and adolescents with persistent ADHD have a more familial form of the disorder than those whose ADHD remits by mid-adolescence.
     Citing molecular biological studies of genes affecting dopamine and serotonin as contributors to ADHD and Tourette Syndrome, Comings (1997) considers the two disorders as hereditary spectrum disorders.  This work is said to supplement twin studies which have found that genetic factors play a significant role in both ADHD and Tourette Syndrome, implying a polygenetic inheritance pattern.  The two conditions are best described as spectrum disorders because of their appearance in multiple family members as well as their association with several comorbid disorders including drug and alcohol abuse and conduct disorder.  Sherman and colleagues found greater concordance for monozygotic than dizygotic twins in both teachers’ and mothers’ ratings, providing evidence for the genetic contribution to expression of ADHD (Sherman et.al., 1997). Twin studies can tell us as much about environmental contributions as they do about genetic factors affecting the expression of a trait.  Across the twin studies conducted to date, the results have been reasonably consistent in demonstrating that the shared environment contributes little, if any, explanation to individual differences in the trait underlying ADHD (hyperactive-impulsive-inattentive), typically accounting for less than 5 percent of the variance among individuals.  In a study by Levy, Hay, McStephen, Wood, and Waldman (1997) shared environmental factors included social class, family educational/occupational status, general home environment, family nutrition, toxins that may be present in the home environment (i.e., lead), and parental and child-rearing characteristics.

Biological Contributors:

     The potentially causative factors associated with ADHD that have received the most research support are biological in nature; that is, they are known to be related to or to have a direct effect on brain development and/or functioning (Barkley, 1997).  Barkley dismisses theories of social and dietary causes of ADHD as having weak support, and instead focuses on the much larger body of empirical evidence which supports the association of biological vulnerability toward poor inhibitory control and ADHD.  Children with pervasive ADHD showed the least inhibitory control and greatest variability of responses compared with a control group (Oosterlaan & Sergeant, 1996).  In addition, MRI scans have shown distinct physiological differences in brain regions between ADHD and control children (Barkley, 1997).
     Pregnancy, delivery and infancy complications (PDIC’s) have been studied to determine correlates and/or predictors of ADHD.  Milberger, Biederman, Faraone, and Guite (1997) found a positive association between ADHD and PDIC’s using linear and logistic regression models in their study.  In addition, very low birthweight children have been found to have an increased prevalence of inattention and hyperactivity; 23 percent of very low birthweight children met research diagnostic criteria for ADHD in contrast to 6 percent of normal birthweight peers (Bottin, Powls, Cooke, and Marlow, 1997).
Milberger et al. (1996) investigated the role of maternal smoking during pregnancy in the etiology of 6-17 year old boys with ADHD found that 22% of the ADHD children had a maternal history of smoking during pregnancy, compared with 8% of the comparison non-ADHD Subjects. This finding remained significant after adjustment for SES, parental IQ, and parental ADHD status.
     Hill, Lowers, and Locke-Wellman (2000) explored the question of whether maternal cigarette smoking or drinking during pregnancy places the child at risk for ADHD.  The longitudinal study examined the association between prenatal exposure to cigarettes and alcohol for the etiology of childhood psychopathology including ADHD.  The findings revealed that prenatal exposure to alcohol was significantly associated with the presence of ADHD although, after controlling for SES and parental antisocial personality disorder, this finding did not remain significant.  Furthermore, the findings did not confirm the association between cigarette use and ADHD reported by Milberger et al. (1996).

Family Contributors:

     Research encompassing family contributors to ADHD has included studies of parental psychopathology, parenting styles, and parent-child interactions.  Viewing family factors and their relation to ADHD through the perspective of the transactional model has implications for both the etiology and treatment of the disorder.  The transactional model proposes that maladaptive behaviors and/or disorders such as ADHD can be viewed in terms of the “reciprocal effects of children on their environmental contexts and contexts on children” (Sameroff & Chandler, 1975; Sameroff & Fiese, 1988).
Nigg & Hinshaw (1998) highlighted two significant findings in their examination of the role of specific parental characteristics in relation to ADHD; 1) boys with ADHD were more likely to have mothers with a major depressive episode and/or marked anxiety symptoms in the past year, and fathers with a childhood history of ADHD, and 2) boys with comorbid ADHD and Oppositional Defiant or Conduct Disorder had fathers with lower Agreeableness, higher Neuroticism, and more likelihood of having Generalized Anxiety Disorder.
     Pfiffner, McBurnett, Lahey, Loeber, Green, Frick, and Rathouz (1999) examined the relationship of parental psychopathology to similar forms of comorbid psychopathology in children with ADHD (Pfiffner et.al., 1999).  Their findings suggest that type of child psychopathology accompanying ADHD (internalizing and/or externalizing) is concurrently predicted by the same type of parental psychopathology.  This finding contrasts with theories that comorbidity is simply a reflection of more severe psychopathology among children with ADHD and instead supports specific modes of familial transmission.
Johnston and Freeman (1997) assert that the social context within which ADHD behaviors are displayed is an important etiological consideration.  In this study of children with and without ADHD and the parent-child relationship, parents of ADHD children viewed the disorder as primarily internally caused, beyond the child’s control, and as relatively stable over time.  These beliefs are consistent with a neurobiological etiology of ADHD.
      Weinstein, Apfel, and Weinstein (1998) examined personality traits and background variables of mothers and children with and without ADHD.  Mothers with ADHD had elevated scores on Neuroticism and Conscientiousness.  Furthermore, neuropsychiatric disorders, atypical sexual events, and familial alcoholism were found with more frequency in the group with ADHD mothers and ADHD children.
     Woodward, Dowdney, and Taylor (1997) compared child and family factors in clinically referred boys with ADHD and those not referred.  Results suggest that clinic referral is more likely in children with hyperactivity when the parent is having difficulty coping and the child is experiencing greater peer and emotional problems in school.
     White (1999) points out the confluence of findings from studies examining parent-child interactions suggests that parents of ADHD children tend to provide more impulse-control directions, encouragement, and disapproval than parents of non-ADHD children.  Research has indicated that these parent behaviors persist after the child’s behavior improves.  Thus, it is unclear whether these parental behaviors are responses to the behavior problems of the child.  The parent-child relationship may be viewed through a transactional lens as an on-going, reciprocal transaction.  For example, raising a child with ADHD may continuously stress the parent and, therefore, affect the quality of the parent-child relationship, potentially impacting the child’s behavior (White, 1999).
     Viewing these family factors and ADHD through the transactional model has important implications for intervention strategies. Treatment plans might address the familial context through interventions such as parent-skills training, coping techniques.  in order to modify individual behaviors and contextual factors which may be contributing to the increased rate of observable characteristics of ADHD.

Cognitive and Neurological Contributors:

      The early onset of the symptoms in ADHD and their relatively persistent nature over time, their association with other developmental disorders believed to arise from neurological development or impairment (i.e., learning disabilities, language disorders, motor abnormalities, and IQ), their significant relationship to peri and postnatal adversities, and their relatively dramatic improvement by stimulant medication have served to repeatedly focus research attention on possible causal neurodevelopmental factors (Barkley, 1997).
      Biederman and Spencer (1999) reviewed neurobiological and pharmacological research in order to investigate the hypothesis that a dysregulation of the central noradrenergic networks is responsible for the pathophysiology of ADHD.  The noradrenergic system is believed to modulate higher cortical functions including attention, especially the maintenance of arousal, a cognitive function that is believed to be deficient in ADHD. Pharamocological studies provide strong evidence that drugs with noradrenergic and dopaminergic pharmacological profiles can be used to effectively treat ADHD.  The authors conclude, “Although there is no single pathophysiologic profile of ADHD, much data do implicate dysfunction in the fronto-subcortical pathways that control attention and motor behavior.” Researchers underscore the need for further research to confirm empirical evidence which suggests that norepinephrine may play a key role in the attentional and inhibitory abilities of the prefrontal cortex (Biederman & Spencer, 1999; White, 1999).
      Max, Arndt, Castillo, Bokura, Lindgren, Smith, Sato, and Mattheis (1998) examined ADHD symptomatology and sequelae after traumatic brain injury (TBI) in children and adolescents.  A significant correlation was found for ADHD symptomalogy and a measure of family dysfunction when family psychiatry history, SES, and severity of TBI were controlled.  Results indicate that changes in ADHD symptoms in the first two years after TBI was significantly related to the severity of TBI, suggesting implications for a neurological basis of ADHD.
      Sheppard, Bradshaw, Purcell, and Pantelis (1999) suggest that the high level of comorbidity of both OCD and ADHD in Tourette’s suggests that the gene responsible for Tourette’s Syndrome may at least be responsible for an increased susceptibility to these two disorders.  The authors suggest this may be due to the neuropathological overlap and/or a neurochemical imbalance.  This examination of the comorbidity among disorders is not meant to discount the idea that these disorders can exist on their own with their own etiologies.
      The broad definition of executive function has guided current research towards the testing of various interpretations of impulsiveness/response inhibition in ADHD.  Such models include: An underlying deficit in a central act of control; a dysfunction in the energetical/state-regulation of motor control; and a deviant cognitive style designed to reduce the subjective experience of delay (Tannock, 1998).  The following studies address the executive function process in individuals with ADHD.
     Carte, Nigg, and Hinshaw (1996) used a neuropsychological battery to measure executive functioning in boys with and without ADHD.  When tasks required a slow pace, selective attention demand, and rapid automatic naming, subjects with ADHD performed more poorly than controls.  Results are consistent with hypothesized deficits for ADHD in organization and planning, possibly mediated by frontal systems, as well as with the cognitive model of response organization.
      Nigg (1999) considered the neuropsychological executive functions of behavioral or response inhibitions as an etiological factor in ADHD in a replication study.  Results indicate that deficits in motor inhibition processes are associated with the DSM-IV ADHD Combined Type.  However, whether the response inhibition is a frontal, behavioral inhibition system or some other inhibition process remains to be explored.  While recent advances in structural and functional imaging techniques of the brain are leading to a new understanding of disorders such as ADHD, functional studies are necessary to determine which anatomical abnormalities have functional sequelae, as well as to demonstrate abnormal cognitive processes inferred from such neuropsychological studies (Tannock, 1998).

Psychosocial Contributors:

     Sandberg and Garralda (1996) state that a number of psychosocial factors are associated with the development of ADHD although it seems unlikely that a direct causal relationship exists in this case.  Factors that are associated with ADHD include social conditions, family stability and marital discord, psychiatric disorder in parents, parenting styles, and the quality of family interactions.  In particular, they highlight social conditions and maternal depression as highly correlated with ADHD.
     Another factor that is well associated with ADHD in the research literature is the relationship between ADHD and temperament (White, 1999).  A high level of activity or hyperactivity is perhaps the most salient temperamental trait of ADHD children.  These children are generally markedly distractible and impulsive and, therefore, tend to be most readily diagnosed due to their behavior frustrating teachers and caretakers.  One popular explanation offered to explain the impulsivity that is characteristic of individuals with ADHD is that they are constitutionally underaroused and thus seek external stimulation.  This hypothesis is supported by empirical evidence suggesting that children and adolescents with ADHD are more likely than their non-ADHD peers to engage in risky behavior.  However, these youths not only tend to seek out arousing experiences, they also have lower levels of inhibitory control when presented with high levels of stimulation (White, 1999).
     Temperamental difficulties related to disinhibition are considered to relatively remain stable throughout the lifespan of the individual with ADHD (White, 1999).  In a study mentioned earlier by Oosterlaan and Sergeant (1996), ADHD children demonstrated poorer inhibitory control and a slower inhibitory process than control group children in response to a stop signal task.  It is interesting to note that aggressive children showed a lack of inhibitory control and a slower inhibitory process that were similar to the ADHD children.
     Hinshaw, Zupan, Simmel, Nigg, and Melnick, (1997) examined the predictive power of behavioral, internalizing, and familial variables with respect to peer status in boys with and without ADHD.  Aggression, covert behavior, and authoritative parenting beliefs were the independent predictors of both negative peer status and peer social preference.  Authoritative parenting beliefs were stronger predictors in peer status in children with ADHD than in comparison youth.
     Harvey (1998) studied how parent’s employment influences conduct problems in children with ADHD.  Results demonstrated that time spent in employment indirectly affected childcare workload and parental well-being for mothers only.  The more time that mothers spent at work, the lighter the childcare workload, which was then related to mothers’ greater parenting well-being and fewer conduct problems for the children.
     The transactional model can again be used in the domain of psychosocial contributors to explain the interacting effects of the individual with ADHD and the given context.  While the transactional model may not explain the underlying causes of ADHD, it does offer explanations as to how the individual and the environment effect one another in a reciprocal manner.  For example, a child’s temperament may solicit negative responses from adult caretakers and peers, whose responses may, in turn, contribute to future behavior problems. Consequently, throughout the individual’s growth and development over time, their unique ADHD symptoms may fluctuate depending on the surrounding environment and their interactions with it.

Developmental Contributors:

     Combining several of the previously discussed etiological factors of ADHD, Barkley suggests that ADHD is a “developmental disorder of behavioral inhibition that impairs the development of self-regulation (executive functioning) and is not, as its name implies, chiefly a disorder of attention” (Barkley, 1997).  Barkley defends this idea by suggesting that not all forms of self-regulation are fully covert or internalized in the early school-age years and may not be so until early adolescence.  Thus as one develops, their ability to control behavior shifts from an external governance to an internal regulation.
     The understanding of the development of ADHD symptomatology is important because of the apparent relationships between these symptoms and subsequent development of behavior problems and educational, occupational, and interpersonal maladaptions.  Olson (1996) states “behavior deviance is the product of a continuous, dynamic interplay between qualities that individual children bring to their social interactions and characteristics of the immediate caregiving environment and its broader social-ecological context”.
     From this perspective, risk factors, vulnerability factors, and resiliency factors are all essential in the understanding of the eventual outcome of behavioral disorders.  In the research literature, positive outcomes for ADHD children are associated with higher IQs, fewer health problems, an internal locus of control, physical health, high self-esteem, positive coping skills, achievement orientation, and social skills (White, 1999). Although these characteristics may serve as protective factors for ADHD children, low levels of these same traits characterize the disorder itself.  ADHD children are more likely than non-ADHD children to have inferior social skills, lower achievement orientation, and an external locus of control.  Hence, the less ADHD symptoms that the child has, the more positive his or her trajectory is likely to be (White, 1999).  Furthermore, at the family level, high levels of cohesion, support, and warmth as well as higher SES and two-parent families with fewer children are predictors of positive, long-term outcomes for ADHD children (Hechtman, 1996).
      Seidman, Biederman, Faraone, Weber, and Oullette (1997) extended studies on developmental processes in the neurophysical investigation of ADHD.  Related to developmental progression, neuropsychological test performance generally improved with age for both the ADHD and non-impaired samples.  The youngest participants with ADHD had the lowest performance scores for al groups.  Significant neuropsychological impairment continued to be present for the ADHD group relative to controls, which contrasts with the idea that children “outgrow” ADHD in the adolescent or adult years.
     Nolan, Volpe, Gadow, and Sprafkin (1999) addressed the developmental approach to the diagnosis of ADHD by examining age, gender, and comorbidity differences in the three different subtypes.  Results indicate that hyperactive/impulsive behavior was more common in adolescents.  Subjects who exhibited symptoms of both inattention and hyperactivity/impulsivity were more likely to show behaviors characteristics of oppositional and conduct disorders, than those who were only considered inattentive.
 

II.  DEVELOPMENTAL APPROACH

     The developmental approach is a contemporary framework for understanding psychopathology.  A fundamental tenet behind this approach includes descriptions of developmental deviations in relation to normal patterns of functioning.  Manifestation of psychopathology is the result of life-long interactions between genetics, biological dispositions and the social environment.  Two undergirding principles within the developmental psychopathology framework are equifinality, which refers to the multiple paths that can lead to the same outcome, and multifinality, which suggests there are various possible outcomes to similar developmental pathways.  Thus, according to this paradigm, an ecological and transactional approach, which takes into account the influence of many factors (for example, genetic, biological, social, and familial) throughout the developmental process, would best be able to explain eventual outcome.  It is extremely difficult to tease apart the factors contributing to a specific trajectory.  White (1999) summarizes, “A complex cluster of biological, psychological and situational factors appear to be related to the etiology and symptom presentation of ADHD.”
     Developmental psychopathology is a product of ontogenetic, biochemical, genetic, biological, physiological, cognitive, social-cognitive, socioemotional, environmental, cultural, and societal influences on behavior (Cicchetti and Cohen, 1995).  When considering Attention Deficit Hyperactivity Disorder (ADHD), the multiple proposed causal pathways and the inability of researchers to empirically account for a single cause for this disorder is indicative of the notion of equifinality.  Further, the large number of identified symptoms (of which relatively few are necessary for an ADHD diagnosis) will inevitably result in a wide variety of profiles that are given the ADHD label.  The heterogeneity of the disorder appears to be consistent with the multifinality tenet of the developmental approach.  A developmental-systems perspective will need to take into account the normal variation in development (e.g., in different domains within an individual as well as variation in one domain of development between individuals).  This will require the use of multiple measures, assessment of more than one domain of development, and the study of various age-groups of children (Tannock, 1998).
      Etiology of ADHD remains unclear, although multiple factors such as genetic susceptibility, biochemical dysfunction, and environmental interactions have been proposed.  Accordingly, the various etiological models have different implications for diagnostic assessment, treatment, and management.
      Extensive evidence exists which supports a heritability factor for attention deficit hyperactivity disorder, with greater risk of the disorder being found among family members.  Biological and neuroanatomical studies involving neuro-imaging have measured cerebral blood flow as well as cerebral glucose metabolism and scanning techniques have documented physical abnormalities in particular brain regions, especially the frontal lobes, for adults and children with ADHD.  In addition, pregnancy and infancy complications can be an influencing factor.  Low birthweight children have been found to be particularly at risk for ADHD and other learning disorders.  Current attempts focus more on a framework that incorporates a multiplicity of causal factors underlying ADHD.  The developmental perspective asserts the interactional nature of the organism with environmental contexts.  Although the preponderance of evidence supports a genetic-neurobiological etiology, the developmental perspective has emphasized the interactional nature of the organism with environmental contexts.  Neuropsychological testing has suggested that while the developmental trajectory for ADHD is linear, normal brain maturation processes may attenuate symptoms over time, although ADHD is generally believed to be a lifelong disorder.  Furthermore, the manifestation of ADHD symptomatology may change over time.  For example, hyperactivity in childhood evolve into a subjective sense of restlessness in adolescence.  Considering the heterogeneity of children diagnosed with ADHD, such diverse etiological evidence may facilitate an enhanced diagnostic structure with greater specificity.  That is, there may be distinct alternative pathways towards a diagnosis of ADHD.
 

III. ADHD WEBSITES

Top Ten Websites

www.aap.org/policy/ac0002.html
Title: Diagnosis and Evaluation of the Child with Attention-Deficit/Hyperactivity Disorder (AC0002)
Author: American Academy of Pediatrics
 This website features practice guidelines for the assessment, diagnosis, and treatment of school-aged children with attention-deficit/hyperactivity disorder (ADHD).  Although these guidelines are intended for primary care clinicians working in primary care settings, mental health care professionals, educators, and students may find this site informative, as the youth’s primary care provider is an integral member of the evaluation team.  The Committee on Quality Improvement of the American Academy of Pediatrics selected a panel of experts in pediatrics, neurology, psychology, child psychiatry, development, epidemiology, and education in order to develop an evidence base of research literature, which was used to formulate these recommendations.  Major themes include child and family assessment, school assessment, and comorbidity.  These practice guidelines were published in the May 2000 edition of Pediatrics.

www.add.about.com/health/add/ OR www.add.miningco.com/health/add/
Title: Attention Deficit Disorder
 Both addresses will link you to a website containing a wide variety of practical resources for ADHD.  The website is also an excellent search engine for ADHD research abstracts/summaries (e.g., the NIMH Nultiodal Treatment Study of Children with Attention Deficit Hyperactivity Disorder) and journal articles. For example, there are links to research journals such as the Journal of Abnormal Child Psychology as well as to abstracts from the National Institute of Health (NIH) conference.  The website also contains other ADHD topics for parents such as Ritalin, the presentation of ADHD at different age levels, special education, advocates/attorneys, and book reviews.  One unique feature of this website is summaries of ADHD subtopics in Spanish.  This may be a good resource for Spanish-speaking parents.

www.addinschool.com
 This website provides interventions and resources for parents and education professionals.  Practical tips and advice are presented separately for elementary and middle/high school level students.  Examples of topics include: Classroom set-up and ADHD students, presenting lessons to ADHD students, giving tests to ADHD students, improving the socials skills of ADHD students, assisting the ADHD students with organization, increasing the on-task behavior of ADHD students, and dealing with the impulsive behaviors of ADHD students.  This is website may serve as a valuable resource for parents and education professionals seeking accommodations for ADHD students that can be incorporated into the everyday classroom routine without a great deal of effort.

www.addwarehouse.com
This website provides abundant information on assessment and evaluation procedures currently used by school psychologists and other professionals. The ADDwarehouse website provides the most current information available on attention deficit disorders.  Teachers, health-care professionals, parents, and children and adults with ADD can get information about a broad selection of products and quality service. Qualified professionals can order assessment measures through this website such as the BASC, Conners Rating Scale, ACTeRS, All Child and Adolescent Symptom Inventories, Attention-Deficit Scales for Adults, The Continuous Performance Test products, Gordon Diagnostic System, and T.O.V.A.

www.chadd.org
Title: Children and Adults with Attention Deficit Disorders
Written by parent advocates for parents, this web site contains an introduction to the disorder ADHD, an empirically sound discussion of both helpful and controversial treatments, and behavioral interventions for parents who have or believe they may have a child with ADHD.  CHADD is a national organization, which has local chapters in many cities.  This website provides current information on medical, scientific, educational and advocacy issues.  The literature includes position papers, government publications, current research studies (mostly on treatment issues), fact sheets (e.g., legal rights for children with ADD), ADD in the media, and current events pertaining the organization.  CHADD also has a quarterly magazine for people with ADHD.

www.kidsource.com/LDA-CA/ADD_WO.html
Title: Attention Deficit Disorder Without Hyperactivity: ADHD, Predominantly Inattentive Type
Authors: Jennifer Wheeler, M.A., and Caryn L.  Carlson, Ph.D. of the University of Texas at Austin
Source: The Learning Disabilities Association of California
 This website provides a detailed description of Attention Deficit Disorder Without Hyperactivity, Predominantly Inattentive Type (ADHD, IA).  The authors begin with a discussion of ADHD, IA as a valid DSM diagnostic category.  The contents also discuss etiology, activity level, accompanying disorders, peer relationships, school performance, and treatment as they relate to ADHD, IA.  This article was found on the Kid Source Online database.  Kid Source Online (www.kidsource.com/) advertises itself as “the source for in depth and timely education and healthcare information that will make a difference in the lives of parents and their children.”

www.medscape.com
Title: Attention Deficit Hyperactivity Disorder
 Medscape is an excellent resource for the latest medical research on the etiology of ADHD as well as other ADHD subtopics.  Searches can be limited specific dates including the last twelve months.  The database includes articles, conference summaries, treatment updates, clinical management modules, practice guidelines, and textbooks. Searches can also be made on other databases such as MEDLINE, News, Drugs by Name, and Drugs by Disease. After filling out a brief online survey, use of the database is free.

www.schoolpsychology.net/p_01.html
Title: School Psychology Resources Online
The School Psychology Resources Online website allows psychologists, parents, and educators to research a variety of developmental psychopathological disorders including ADHD.  Example search results for ADHD included reviews and links to websites such as diagnosis and evaluation recommendations from the American Academy of Pediatrics, a Scientific American article by Russell Barkley, and school-based ADHD accommodations for a 504 plan.

www.scientificamerican.com/1998/0998issue/0998barkley.html
Title: Attention Deficit Hyperactivity Disorder
Author: Russell Barkley- Director of Psychology and Professor of psychiatry and neurology at the University of Massachusetts Medical Center.  He has numerous publications, including two books: ADHD and the Nature of Self-Control (1997) and Attention Deficit Hyperactivity Disorder: A Handbook for Diagnosis and Treatment (1998).
This website provides various etiological information with an emphasis on a neurological basis.  General topics include: Search for a cause of ADHD, From
genes to behavior, Prescribing self-control, Diagnosing ADHD, A psychological model of ADHD, Illustrations of the brain, Further reading, and Related links.  More specifically, in the search for a cause section there is a focus on neurological imaging techniques and genetics.  Information also includes discussions about the different regions of the brain, as well as genetic research focusing on heritability and twin studies.  The main premise of this website is impaired behavioral inhibition and self-control are the central deficits in ADHD.

www.surgeongeneral.gov/library/mentalhealth/chapter3/sec4.html
Title: Mental Health: A Report of the Surgeon General-Chapter 3
Source: The United States Surgeon General
This website is a subsection of the U.S. Surgeon General’s mental health report outlines the following ADHD subtopics: Prevalence, causes (etiology), pharmacological treatment, psychostimulant treatment, psychosocial treatment, behavioral approaches to treatment, Cognitive-Behavioral Therapy, psychoeducation, multimodal treatments, treatment controversies, overprescription of stimulants, and safety of long-term stimulant use.

OTHER WORLD WIDE WEBITES ON ADHD

www.aacap.org/clinical/adhdsum.htm
Title: Summary of the Practice Parameters for the Assessment and Treatment of Children, Adolescents, and Adults with Attention-Deficit/Hyperactivity Disorder
Author: American Academy of Child and Adolescent Psychiatry
This website makes specific recommendations for clinicians faced with the assessment, differential diagnosis, and treatment of children, adolescents, and adults who present with symptoms of ADHD.  Specific recommendations are based on an extensive review of the scientific literature and clinical consensus among experts on ADHD. Comorbidity with other disorders is also described.

www.addclinic.com
 The website provides links to ADHD resources such as support groups and an internet search engine for ADHD.  Many of the websites featured on the homepage advertise alternative treatment products and services for ADHD (e.g., dietary supplements instead of stimulants).

www.add.org
Title:  National Attention Deficit Disorder Association
 The National Attention Deficit Disorder Association is a nonprofit organization, built around the needs of adults and young adults with ADHD.  Information on research, treatment, books on ADD, family issues, legal issues, support groups and personal interviews, and weblinks are available.  A nice way of presenting information is that there
are areas devoted to specific groups (e.g., children, women, and teens) as well as various contexts (e.g., school, work and career).

www.ahcpr.gov/clinic/adhdsutr.htm
Title: Diagnosis of Attention-Deficit/Hyperactivity Disorder
Author: Agency for Health Care Policy and Research (AHCPR)
 This website is a technical review summarizing current scientific evidence related to ADHD as well as the value of various evaluation methods for the diagnosis of ADHD.  The sections of the website include Overview, Reporting the Evidence, Methodology, Findings, Future Research, and Availability of Full Report.  The author of this website is the Agency for Health Care Policy and Research (AHCPR).  AHCPR describes itself as “developing scientific information for other agencies and organizations on which to base clinical guidelines, performance measures, and other quality improvement tools, under the Agency's Evidence-based Practice Initiative, which was launched in the fall of 1996.”

www.adhd.com.au/ADHDaeti.html
Title: The etiology of ADHD: Evidence of a neurobiological basis and treatment implications
Author/Affiliation: Jacques Duff- Behavioral Neurotherapy Clinic
This website concludes that ADHD is caused by inherited factors that are manifest in abnormal brain morphology, and associated with an underlying neurological disregulation and underarousal of the frontal lobes.  Information provided at this site was helpful because an historical account for various explanations of ADHD were stated along with available empirical evidence to support their claims.  Sections in this website are divided as follows: Toxins, Family and environmental factors, Perinatal factors, Genetic evidence, Brain morphology, and Neurotransmitter activities.  A significant amount of information is provided on neurobiological treatment interventions.

www.btinternet.com/~black.ice/addnet/
Title: Collaborative Management of Students with ADHD
The department of education in conjunction with specialist medical practitioners provides information to support teachers and schools to effectively manage students with ADHD.  The information provided in this website are practical guidelines for teachers and school personnel to modify the educational environment and/or instructional approaches in order to enhance the opportunities for these students.  Topics which are covered include: problem solving, organization, sustained attention, social skills, impulsive/aggressive behavior, non-compliance, and off-task behaviors.

www.cdipage.com/adhd.htm
Title: About Attention Deficit Hyperactivity Disorder- ADHD/ADD
 This website provides information about attention deficit hyperactivity disorder, including diagnosis, treatment, classroom management, parent education, behavior modification, communication, and family relationships.  The information is updated as needed to reflect current research on ADHD.

www.eegspectrum.com/
Title: EEG Spectrum- Mental Fitness Training: Neurofeedback Research and Clinical Services
 This website provides extensive information about EEG training and its application to individuals diagnosed with ADHD.   Background information describing the training procedures, as well as its clinical application to a variety of conditions are outlined.  The authors imply that neurofeedback can be used for many conditions and disabilities in which the brain is not functioning normally.  Clinical neurofeedback services, clinical and scientific articles, professional training courses, as well as general news and announcements are covered under the primary topics.

www.findarticles.com
 This website can be used to search for research journal articles related to ADHD in addition to other topics.  An example of an article related to the assessment and diagnosis of ADHD that is available on the site is a study by Weiler (1999) published in the Journal of the American Academy of Pediatrics entitled “Mother and teacher reports of ADHD symptoms: DSM-IV questionnaire data.”  This article examines the component structure and distribution of scores of the Diagnostic Rating Scales, which are brief, DSM-IV-referenced parent and teacher questionnaires designed to screen children for ADHD symptoms.

www.gsi-add.com/default.asp
Title: ADD/ADHD Attention Deficit Hyperactivity Disorder (Dr. Gordon)
 Dr. Gordon along with GSI Publications, Inc. and Gordon Systems, Inc. has created this website to provide resources on information and products about ADHD.  Many of the materials are useful for clinicians and licensed professionals.  The web site provides a comprehensive list of assessment devices (i.e., rating scales, and structured interviews).  Furthermore, the research referenced is categorized as such: General, longitudinal, ADHD in adults, medication, and educational issues.  Likewise, there is an extensive list of books/videos (e.g., books in Spanish for parents and children).

www.health-center.com
 This website can be used to search for a variety of subtopics related to ADHD.  Subtopics are organized in folders according to their utility for kids, parents, physicians, teachers, teens, therapists, adults, etc.  The site also features the ADHD Living Guide Project, providing information on dealing with ADHD at school and home, funded by the Agency for Healthcare Quality and Research.  In addition, the website features a discussion bulletin board, a link to Medline, and page viewing in Spanish.

www.info@adhd.com.au
Title: Behavioural Neurotherapy Clinic
The authors of this website asserts that a particular treatment modality called neurotherapy appears to provide an effective treatment for ADHD, based on the studies reviewed. The authors discuss their study which will use sophisticated SSVEP (Steady State Visually Evoked Potential) Functional Brainmapping, IQ testing, neuropsychological assessment and behavioural measures before and after Neurotherapy to evaluate the effectiveness of specific Neurotherapy protocols as treatment for ADHD and Learning Difficulties. The study will be conducted over a period of twelve months, and will involve 60 ADHD children. Lastly, several large international clinical studies are
underway, some sponsors include EEGSPECTRUM, and the Biofeedback Foundation of Europe. The Brain Sciences Institute (Swinburne University) is also conducting a scientific investigation of the effectiveness of Neurotherapy. This innovative treatment approach and the related literature seem to be interesting and unique.

www.ldonline.org/ld_indepth/add_adhd/ael_success.html
Title: ADHD- Building Academic Success
Author: Appalachia Educational Laboratory (based on information provided by the Office of Educational Research and Improvement- OERI)
 The information provided in this website advocates a multimodal approach of treatment in the educational environment.  The authors adopt the idea that often times there is a mismatch between school environments and children with ADHD which may contribute to school failure.  In an attempt to address this problem, the following topics are discussed: ADHD and school failure, The mismatch of ADHD and school, School’s response to academic failure, School-Child Relationships: A transactional model, Multimodal treatment: Sharing responsibility for learning, Specific, individual accommodations, Comprehensive changes in school environments, and Monitoring performance.

www.newideas.net/attention_deficit/treatment_options/overview.htm
Title: The Attention Deficit Hyperactivity Disorder Information Library
Author: Dr. Douglas Cowan
 This Attention Deficit Hyperactivity Disorder Information Library is a part of the NewIdeas.Net family of ADD ADHD related websites. This website presents information in a straightforward manner suitable for parents. Treatment options, interventions, diagnostic information and other resources are discussed.  The website claims to glean its information from ADD/ADHD research findings as well as from the observations of professionals working in the field.

www.newideas.net/p0000392.htm
Title: ADHD- Diagnosing ADD & ADHD in Children and Teens (Dr. Doug Cowan)
 The information provided on this website is from a clinical perspective and appears to be written for parents.  The author states two main problems in the diagnosis of ADHD: 1) the over-diagnosis, which is a result of incomplete assessment procedures and 2) under-diagnosis, which he describes the school psychologists’ reports which include information appearing to describe many characteristics of ADHD, yet no formal diagnosis or label is prescribed to the child.  The author addresses several components in a thorough ADHD assessment: a) physical exam, b) in-depth parent interview, c) parent and teacher rating scales, d) clinical interview with the child, e) psychological testing, and f) TOVA.

www.nyspsych.org/cybercol/sept97/perry.html
Title:  Attention Deficit Hyperactivity Disorder (ADHD) Causes
Author:  Richard Perry, M.D.
This article reiterated the uncertainties with regards to the etiology of ADHD which points to the necessity for further investigations in this area.  According to the author, it is the general opinion from those in the field today that the causes of ADHD lie within the abnormalities of certain regions of the brain.  However, and as stated by the author in this case, conclusive evidence to support this aim has yet to be found.  On the other hand, evidence to demonstrate the genetic component to this disorder appears to be well established based on twin studies and studies of close family and close relatives of those with this disorder.  Finally, considerations must likewise be given to other factors such as pre- and perinatal complications and family situations.
 

VI.   CONCLUSIONS

     Etiology of ADHD remains unclear, although multiple factors such as genetic susceptibility, biochemical dysfunction, and environmental interactions have been proposed.  Accordingly, the various etiological models have different implications for diagnosis, treatment, and management.
     Extensive evidence exists which supports a heritability factor for  attention deficit hyperactivity disorder, with greater risk of the disorder being found among family members. Biological and neuroanatomical studies involving neuro-imaging have measured cerebral blood flow, cerebral glucose metabolism, and scanning techniques have documented physical abnormalities
in particular brain regions, especially the frontal lobes, for adults and children with ADHD. In addition, pregnancy and infancy complications can be an influencing factor.  Low birthweight children have been found to be particularly at risk for ADHD and other learning disorders. Current attempts focus more on a framework that incorporates a multiplicity of causal factors underlying ADHD.  The developmental perspective asserts the interactional nature of the organism with environmental contexts.
   Although the preponderance of evidence supports a genetic-neurobiological etiology, the developmental perspective has emphasized the interactional nature of the organism with environmental contexts.  Parental attributions, parental psychopathology, and behavioral management techniques have been found to be significantly related to the severity of expression of ADHD behaviors.  Neuropsychological testing has suggested that while the developmental trajectory for ADHD is linear, normal brain maturation processes may attenuate symptoms over time, although ADHD is generally believed to be a lifelong disorder.  Considering the heterogeneity of children diagnosed with ADHD, such diverse etiological evidence may facilitate an enhanced diagnostic structure with greater specificity.  That is, there may be distinct alternative pathways towards a diagnosis of ADHD.
 
 

Return to Top
 

I. ASSESSMENT

     The assessment of behavioral disorders, such as ADHD, must be guided by research on the classification and core features of the disorder.  Multiple sources and multiple varieties of information are necessary because the level of agreement among sources and between types of information is relatively low (Forbes, 1998). The current research strongly suggests that an optimal assessment protocol relies upon several methods, utilizing several different sources of information obtained from different settings and informants (Barkley & August, 1998).  ADHD diagnosis is increasingly common.  The driving force behind an ADHD diagnosis must not be to qualify a student to receive medical treatment to improve behavioral disruptions in the classroom or to receive extended time on standardized tests.  To circumvent these problems, direct and frequent communication between school personnel, medical professionals and family members needs to occur during assessment and treatment. Furthermore, assessment results should be used to design intervention strategies.
     The first diagnostic task in the classification of ADHD is ruling out alternative causes or establishing the primary problem (e.g., head injuries, metabolic or endocrine disorders, learning disabilities, substance abuse, and giftedness).  Secondly, the situational variations of problems directs that multiple sources of information be obtained from the different domains of the child’s life (e.g., home, school).  Thirdly, it is necessary to consider developmental issues (e.g., age of the child, maturity). Various assessment methods have been utilized to determine whether a child is displaying behaviors characteristic of ADHD at a developmentally inappropriate level and to a problematic or symptomatic degree.  These methods of assessment include: Interviews, standardized child behavior rating scales, peer-referenced assessment, laboratory measures, and direct observation. Multi-method

Interviews:

     The clinical interview is an essential component of the assessment process in diagnosing ADHD (Hechtman, 2000). Several interview schedules have been developed for use with children and adolescents as well as with primary caregivers.  Interviews may be conducted with a child’s teachers, parents and others such as school staff or childcare providers.
Teachers provide important observations of the child’s behavior, social skills, and academic performance.  It is especially helpful when teachers are able to identify which situations trigger problematic behaviors as well as what type of consequences result.  Furthermore, teacher reports about what instructional and intervention strategies that have been effective or ineffective is essential for both assessment and intervention planning (Brown, 2000).
     There are several advantages to a well-conducted, comprehensive interview such as building rapport and coverage of a broad range of topics related to ADHD diagnosis and treatment planning (Brown, 2000).  Hechtman (2000) outlines the important parameters that can be assessed in the clinical interview, which include: An extensive family history that explores family history of ADHD symptomatology as well as other psychiatric disorders, the family situation, parental stress level, and psychosocial adversity (family conflict, social support, poverty, etc.). Other relevant subjects to cover in the interview are details of the referral concerns; medical and developmental history; and academic performance and experience; behavior problems and peer relationships. Furthermore, diagnostic interviews are typically tied to the most recent revisions of the DSM.
     Some disadvantages may be that they are time consuming, and may not provide norm-referenced information.  In addition, the reliability of child self-report interviews (before age 9) may be questionable. Children, particularly over age 10, tend to be reliable in reporting internalizing symptoms such as depression, whereas they tend to underreport externalizing symptoms such as aggression.  Although parental reports of their children’s behavior are generally reliable, excessive stress may result in increased reports of behavior problems (Brown, 2000).   A list of the more common interview schedules in provided as well as recent studies researching the use of such instruments. Popular instruments include the Diagnostic Interview Schedule for Children (DISC-R; Schwab-Stone, Fisher, Piacetini, Shaffer, Davies, and Briggs, 1993), the SCICA (Structured Interview for Children and Adolescents (SCICA; McConaughy & Achenbach, 1994), the Diagnostic Interview of Children and Adolescents (DICA-R; Boyle, Offord, Racine, and Szatmari, 1996), and the Structured Developmental History (SDH) of the multidimensional Behavior Assessment System for Children (BASC) (Kamphaus, Reynolds, & Hatcher, 1999).
     The use of structured interviews adds a standardized, quantifiable dimension to the clinical assessment (Hechtman, 2000).  Brown (2000) recommends the use of two widely used structured interviews, the Diagnostic Interview Schedule for Children (DISC) and the Semistructured Clinical Interview for Children and Adolescents (SCICA) due to their specific diagnostic criteria and relatively high reliabilities.
     Schwab-Stone, Fisher, Piacetini, Shaffer, Davies, and Briggs (1993) examined the test-retest reliability and internal consistency of the Diagnostic Interview Schedule for Children (DISC-R).  Forty-one adolescents and thirty-nine of their parents were administered the DISC-R.  Test-retest reliability for symptom scales was excellent for the parent DISC-R and good for the child version, except for Oppositional Defiant Disorder.  Internal consistency was satisfactory for symptom items comprising most diagnoses.
     McConaughy and Achenbach (1996) tested the predictive power of the Semistructured Clinical Interview for Children and Adolescents (SCICA), combined with a standardized parent scale, the Child Behavior Checklist (CBCL), and a standardized  teacher scale, the Teacher's Report Form (TRF), for children with emotional and behavioral disorders (EBDs) or learning disabilities (LDs) and nonreferred children. The authors found that the majority of SCICA, CBCL, and TRF scales were able to significantly discriminate between subjects with EBDs and nonreferred subjects. Several scales were also able to discriminate between subjects with EBDs and LDs.
      Another structured interview that is commonly utilized for ADHD assessment is the Diagnostic Interview for Children and Adolescents (DICA-R). Boyle, Offord, Racine, and Szatmari (1996) compared the reliability and validity of the DICA-R and theOntario Child Health Study Scales, (OCHS-R), a self-administered checklist, on two administration occasions, 1-3 weeks apart.  Differences in test-retest reliability between the two instruments were small.  Validity coefficients were slightly better for the checklist classifications of disorders listed in the DSM-III-R.  Differences in reliability and validity were also small between the two measures.
     A structured diagnostic clinical interview with the child’s primary caregiver is also useful (Ammerman, Hersen, & Last, 1999).  One instrument that can be used or this purpose is the Structured Developmental History (SDH).  The SDH is one component of the multidimensional Behavior Assessment System for Children (BASC).  The SDH is an extensive history and background survey that may be used as either part of an interview with the child’s primary caretaker administered by the clinician.  This comprehensive questionnaire systematically gathers diagnostic information including developmental events, medical problems, social history, and family problems that may affect the child’s behavior (Kamphaus, Reynolds, & Hatcher, 1999).

Behavior Rating Scales:

     Behavior rating scales (teacher or parent) have become more commonplace in child assessment of ADHD and are designed to gather information about ADHD symptoms, general social competence, comorbid disorders, and situational variability in behaviors.  These instruments are practical and cost-efficient, although they have been criticized for their limited interpretive value.  The Behavior Assessment System for Children (BASC- Parent & Teacher forms-PRF & TRF; Reynolds & Kamphaus, 1992) and the Achenbach Child Behavior Checklist (CBCL- Parent & Teacher scales- PRS & TRS; Achenbach & Edelbrock, 1983) appear to be the most widely used and have the most support for reliability and validity.  Other available behavior rating scales include: Connors’ (CTRS 39, 28 and CPRS-R; Connors, 1989); the ADHD Symptoms Rating Scale (ADHD-SRS; Holland, Gimpel, and Merrell, 1998); the Devereux Scales of Mental Disorders (DSMD; Smith, Wigenfeld, Hilsenroth, Reddy, and LeBuffe, 2000); Attention Deficit Disorder Evaluation Scale (ADDES; McCarney, 1989); ADD-H Comprehensive Teacher Rating Scale (ACTeRS; Ullmann, Sleator, and Sprague, 1991); and the AD/HD Rating Scale-IV (Teacher and Parent forms; DuPaul, Anastopoulos, Power, Murphy, and Barkley, 1996).  Following are research studies regarding the use of various scales.
Kamphaus, Reynolds, and Hatcher (1999) review recent research on the use of BASC and found that most of the studies focused on the assessment and diagnosis of clinical populations such as ADHD.  The confluence of finding suggests that the BASC is comparable to the CBCL for the diagnosis of ADHD Combined Type.   However, the BASC appears to be superior to the CBCL for diagnosing children with externalizing disorders, specifically ADHD Primarily Inattentive Type. Researchers identify the rational derivation of the BASC scales as another advantage of the BASC over the CBCL.
     Vaughn, Riccio, Hynd, and Hall (1997) compared the effectiveness of discriminating ADHD subtypes using the Parent Rating Scale and the Teacher Rating Scale of the Behavior Assessment System for Children (BASC) and the Parent Report Form and the Teacher Report Form of the Achenbach Child Behavior Checklist (CBCL).  Their results indicated that correlations were significant for a number of scales.  Discriminant analysis did not strongly favor either measure in differentiating children with ADHD from those who did not meet diagnostic criteria.  The authors stated that results show the BASC Teacher Rating Scale has better predictive ability for children who do not meet ADHD criteria.  For subtypes of ADHD, specifically the predominantly inattentive type, results show an advantage for the use of the BASC.
     Connors, Sitareios, Parker, and Epstein (1998) evaluated the factor structure, reliability, and criterion validity of the revised Connors Parent Rating Scale (CPRS-R).  Exploratory and confirmatory factor-analytic results revealed a seven-factor model including the following factors: Cognitive Problems, Oppositional, Hyperactivity-Impulsivity, Anxious-Shy, Perfectionism, Social Problems, and Psychosomatic.  The psychometric properties of the revised scale seem to demonstrate good internal reliability
coefficients, high test-retest reliability, and effective discriminatory power.  Advantages of the CPRS-R include a corresponding factor structure with the Connors Teacher Rating Scale-Revised and comprehensive symptom coverage for ADHD and related disorders.
     Holland, Gimpel, and Merrell (1998) investigated the reliability and validity of the ADHD Symptoms Rating Scale (ADHD-SRS) used by 1006 participants.  The results indicate that the ADHD-SRS possesses strong internal consistency reliability and test-retest reliability and moderate cross-informant reliability.  In addition, this instrument was shown to have strong content validity.  The authors state several advantages of the use of this instrument over many currently existing rating scales.  One advantage is that the items are based on the DSM-IV classification of ADHD and its symptomatology.  In addition, with 56 items designed to purely assess for ADHD characteristics, this instrument generates a more thorough and complete assessment.
 Smith, Wigenfeld, Hilsenroth, Reddy, and LeBuffe (2000) evaluated the validity of the Devereux Scales of Mental Disorders to discriminate between children and adolescents with ADHD, Conduct Disorder (CD), and no clinical diagnosis.  The results of the study did support the use of the DSMD for distinguishing between clinical and nonclinical subjects.  However, the DSMD Total, Composite and Scale score did not differentiate between the ADHD and the CD youths.  Although the DSMD appears to perform as well or better than other behavior rating scales at differentiating clinical from nonclinical groups, the DSMD is not as able to make subtle distinctions between disorders.  However, the participants with ADHD scored higher on the number of ADHD-related items endorsed and the participants with CD scored higher on the number of CD-related items endorsed.  Thus, clinicians using the DSMD may be able to differentiate between these two highly related disorders by examining the number of disorder-specific items endorsed.

Peers:

     Ammerman, Hersenand, and  Last (1999) suggest that “when social problems are a primary concern, peer measures such as positive and negative nomination procedures, peer rating scales, and/or peer reputation measures are useful in providing important information about the extent and types of peer problems” (p. 67).  Schaughency and Rothlind (1991) also suggest the use of peer nominations in assessments of ADHD.  Specific items such as “can’t pay attention, can’t wait turn, and can’t sit still” correlated well with teacher and observer measures of inattention and hyperactivity.
     Cornett-Ruiz and Hendricks (1993) investigated the effects of labeling and ADHD behaviors on peer judgments.  Fourth through sixth grade subjects watched a brief video of a child displaying stereotypical ADHD behaviors or normal behaviors and was labeled as either ADHD or normal.  Then, the peer raters completed first-impressions rating scales, made predictions regarding subsequent success, and evaluated a hand-written essay.  Findings revealed that the ADHD behavior but not the label resulted in a significant negative impact on the peer raters’ first-impressions and prediction scales.
     Although peer ratings may make a valuable contribution to diagnostic assessment, the evaluation team should consider the effect that a sociometric instrument may have on the child.  For example, the peer rankings may result in increased anxiety or may encourage teasing.

Behavioral Observations:

     Behavioral observations provide opportunities to compare the child’s behavior in a variety of settings in order to gain a more holistic view of the child and a more objective sense of his or her functioning. However, conducting observations can be expensive and time consuming, and are limited in the ability to observe an adequate sample of behavior. Examples of behavioral observation instruments include the Behavioral Assessment System for Children-Monitor for ADHD (BASC- Student Observation System SOS; Reynolds and Kamphaus, 1992) and the Child Behavior Checklist (CBCL- Direct Observation Form DOF; Reed & Edelbrock, 1983 ).
     Assessors can also maximize time spent conducting assessment by incorporating observations during testing into the evaluation report.  Glutting, Robins, and De Lancey (1997) compared the test session behaviors of children with ADHD to unclassified children from the GATSB standardization samples. The ADHD children were matched to the control children according to the background characteristics of age, race, gender, parent educational attainment, and overall cognitive ability.  Test-taking behaviors were rated according to the Guide to the Assessment of Test Session Behavior (GATSB) for the Weschler Intelligence Scale for Children-Third Edition (WISC-III) and the Weschler Individual Achievement Test (WIAT) following the administration of the WISC-III. Results indicated that ADHD children could be distinguished from the matched GATSB control children on the test behavior variables of Inattentiveness, Avoidance and Uncooperative Mood. The inattentiveness dimension of the GATSB best differentiated between the two groups.
     Valid ADHD diagnosis is complicated by heavy reliance upon parent and teacher reports as well as children’s performance on tasks which may be confounded by comorbid learning difficulties. In lieu of a standard assessment technique, Costantino, Colon-Malgady, Malgady, and Perez (1991) “applied an old technique to a new problem by examining attention to projective stimuli.” A structured thematic apperception technique, the Tell-ME-A-Story (TEMAS), was utilized to measure attention to pictorial stimuli depicting characters, events, settings, covert psychological conflicts.  The TEMAS was administered to Black, White and Hispanic ADHD and non-ADHD school-age children.  The results revealed that the ADHD children were significantly more likely that than the non-ADHD children to omit information in the stimuli about characters, events, settings, and psychological conflicts.  Furthermore, prompting with structured inquiries by test examiners was three times more likely to be required for the ADHD children than the non-ADHD children.
     Handen, McAuliffe, Janosky, and Feldman (1998) observed children in a laboratory playroom setting to determine whether children identified as ADHD or controls differed on activity and attentional measures.  Children with ADHD were further divided into ADHD + conduct problems (ADHD + CD) and ADHD-only subgroups.  Results indicated that the ADHD-combined group was significantly more vocal and engaged in a significantly greater number of toy changes than controls during independent play.  Significant group differences were also noted during the restricted academic task, with the ADHD-combined and ADHD + CD groups more off-task and engaging in a greater number of toy touches than controls.

Laboratory Measures:

     Laboratory measures have been used to obtain direct core features of ADHD (e.g., attention span, impulsivity, and motor activity).  While other assessment measures may be criticized for their validity (e.g. unclear comparison standards of children of the same age, cultural variations) and/or subjectivity (e.g., child ratings versus parent ratings), laboratory measures are able to account for these inconsistencies by the objective nature of the assessment.  However, some limitations may involve standardization issues, normative data, and generalization to other contexts.  Specifically, a computerized assessment of attention and impulsively may not relate to assessments of a child’s adaptive behavior in broader social contexts such as home, school, and peer groups.  Thus, greater research is needed in this area to determine its generalization utility.
 The Continuous Performance Test (CPT) is probably the most widely used instrument for attention span or vigilance.  There have been several variations on the basic method of the original CPT, but most researchers continue to follow the design of presenting a series of random letters and requiring the participant to respond when a specific letter, usually an X, appears or when a specific letter, usually an A, is followed by another specific letter, usually an X.  Failure to respond to the specified letter or letter sequence is usually interpreted as a result of inattention.  Responses to incorrect letters or letter sequences are usually interpreted as impulsivity (Forbes, 1998).
     Widely used laboratory measures for ADHD are: The Continuous Performance Test (CPT; Rosvold, Mirsky, Sarason, Bransome, and Beck, 1956), Connors’ Continuous Performance Test (CPT; Connors, 1995), Matching Familiar Figures Test (MFFT; Kagan, 1964), and Test of Variables of Attention (TOVA; Greenberg, 1991).
     Corkum and Siegel (1993) reviewed research studies that employed the CPT in order to examine the possibility of sustained attention deficits in children with ADHD.  The authors concluded that there is no compelling evidence for a sustained deficit in ADHD children.  An alternative theoretical model for understanding the results of CPT performance in ADHD is also provided.
     Mirsky, Pascualvaca, Duncan, and French (1999) present a neuropsychological model of attention based on a factor analysis of data derived from more than 600 children and adults.  The model divides attention into different elements or factors including the capacities of encoding, focusing, executing responses, sustaining attention, shifting attention, and a measure of response stability.  A description is also given of an on-going investigation of children referred to an inner-city family clinic for evaluation of ADHD.  The findings of this ADHD study indicate that several aspects of attention are impaired in children with ADHD and that these impairments are probably not attributable to learning disorders.
     The authors also present an Attention Battery, modified for children, derived from neuropsychological tests in order to assess the various elements of attention.  Preliminary findings from the current study suggest that ADHD children are impaired in various elements of attention as compared to control children: The capacity to focus on a task when distracted and to execute brisk, efficient responses (The Trail Making B Test and the Stroop Word Test); the ability to shift attention in a flexible, efficient manner (the Wisconsin Card Sorting Test); and the ability to sustain attention in both the visual and auditory modalities (CPT); and the capacity to maintain a stable response rhythm in the auditory modality (CPT).  In addition, the preliminary results suggest that ADHD children tended to have more rapid responses than control subjects, yet the responses tend to be more impulsive and more poorly regulated.  For instance, the ADHD children had more CPT commission errors as well as increased Reaction Time (RT) Variance on the auditory CPT in comparison to control children.
     In order to address the question of the possible contributions of learning disabilities to documented attention deficits, the authors also compared the assessment results between the subgroup of children diagnosed with ADHD alone (ADHD) with the subgroup of children diagnosed with ADHD and a learning disability (ADHD+LD).  The only significant difference found between the groups was on the Word and Color naming subtests of the Stroop Test, which appears to be consistent with generally poor reading abilities. Thus, the authors conclude that the impaired attentional elements in the ADHD population are not generally attributable to learning disabilities.
     McGee, Clark, and Symons (2000) found that children with Reading Disorders (RD) had higher scores than both ADHD children and control children on the Connors’ CPT.  Furthermore, the ADHD children did not have significantly higher CPT overall index scores than the control children did.  Phonological awareness tests, consisting of two auditory and two visual  subtests from the Woodcock-Johnson Psychoeducational Battery--Revised,  distinguished the RD children from both the ADHD and the control children. This finding may be due to the Connors’ CPT requiring rapid identification of letters, which is basic deficit in RD children.  The authors point out the danger that RD children could be falsely diagnosed with ADHD if the Connors’ CPT overall index is used as diagnostic tool. ADHD children who did fail the Connors’ were rated as more hyperactive by their teachers. The Connors’ CPT did demonstrate several strengths in this study.  There were no age, order or fatigue effects.  CPT performance was uninfluenced by visual-motor integration, fine motor speed, visual processing speed--with the exception of reaction time--or SES.  In agreement with other studies, the authors found that CPT scores do not consistently identify attention in ADHD children.  In conclusion, the utility of the Connors CPT for differential diagnosis of ADHD is questioned.
     Some clinicians believe that the CPT measures psychomotor speed function rather than sustained attention.  In order to examine this relationship, Chae (1999)  conducted a correlation study between the Performance IQ (PIQ) of the WISC-III and the TOVA, which is commonly used as a CPT.  The relationships between the Freedom from Distractibility (FD) and Processing Speed (PS) indexes of the WISC-III, which are often included in ADHD assessment, with the TOVA were also examined.  The results of forty ADHD children studied indicate that there was no correlation between the TOVA and the PIQ of WISC-III.  Furthermore, the insignificant correlation between the WISC-III Symbol Search subtest, which is regarded as simply measuring psychomotor speed, and Response Time of TOVA supports the conclusion that the TOVA is not a simple of psychomotor speed for the evaluation of ADHD.  It appears that the PIQ and the TOVA measure different qualities of psychomotor functioning.  In addition, the significantly negative correlation between the Object Assembly (OA) and Picture Arrangement (PA) subtests with the TOVA Inattention indicates that ADHD children will not do well in the tasks that require sustained attention.  Hence, the OA and PA WISC-III subtests may be useful screening tools for ADHD.
     Forbes (1998) conducted clinical tests of the TOVA to distinguish between referred children with ADHD/ADD and “other” clinical diagnoses.  The ADHD group differed from the “other” group on TOVA variables and most measures from the Revised Connors Teachers Rating Scale (RCTRS) and ADD-H Comprehensive Teacher’s Rating Scale (ACTeRS).  These results indicate these instruments are measuring relevant but different dimensions of attention deficit disorders.  The TOVA classification criterion of any one variable correctly identified 80 percent of the ADDHD/ADD group and 72 percent of the “other” group. In addition, cases misclassified by teacher ratings were often correctly classified using TOVA.  The authors note that, because the rating scales and the TOVA have inherent differences (e.g., differences in populations studied, differences in diagnostic criteria, differences in scoring), making meaningful comparisons is difficult.  Thus, both appear to be contributing significant amounts of unique information to an ADHD assessment.
     A recent study assessed the usefulness of the CPT, the MFFT, and the actigraph (an acceleration-sensitive device with a solid-state memory used to count and store the number of times accelerations change above a certain threshold per unit time) used in combination to differentiate boys with ADHD from control subjects and to classify them into subtypes (Inoue, Nadaoka, Oiji, Morioka, Totsuka, Kanbayashi, and Hukui, 1998).  In this study, the actigraph measured motor activity in the subject’s trunk area.   Regarding the MFFT, the authors suggest that the “fast inaccurate” category is an important diagnostic sign in ADHD as 16 out of the 20 participants with ADHD were classified in this category.   The participants with ADHD and the controls were differentiated with enough high sensitivity and specificity by the actigraph and the CPT.
    Marks, Himelstein, Newcorn, and Halperin (1999) identified ADHD subtypes using actigraphs and CPTs with a clinically referred sample of participants ranging in ages from 7-11 years old.  Results indicate that the hyperactive-inattentive group was impaired on measures of intellectual functioning and academic achievement relative to the other 3 groups.  In addition, the impulsive-inattentive group was generally rated as more aggressive, although this difference was not statistically significant for all measures.  The authors conclude that these results suggest that such laboratory-based measures may be an effective strategy to categorize diagnostic subgroups of ADHD.
     Silberstein, Farrow, Levy, Pipingas, Hay, and Jarman (1998) used a novel brain electrical imaging method to investigate rapid and continuous changes in brain activity during the CPT in 17 boys (ages 1-14 years) with ADHD and 17 matched-aged controls.  In the interval between the appearances of the A and the X of the correct trials of the CPT-AX, control boys showed transient reductions in steady-state visually evoked potential (SSVEP) latency at right prefrontal sites.  By contrast, boys with ADHD showed no changed or an increase in prefrontal SSVEP latency at right prefrontal sites.  The use of these laboratory measures in this study provide evidence for neurological differences in children with ADHD.  Specifically, these results suggest an increased speed of prefrontal neural processing in children without ADHD following a priming stimulus, and a deficit in such processes in children with ADHD.
 

II. DEVELOPMENTAL PERSPECTIVE

     Utilizing a developmental framework is a useful practice in the assessment of ADHD. ADHD can be viewed as a developmentally relative disorder as findings indicate that ADHD symptoms decline significantly in prevalence and/or change in expression with age across childhood and adolescence.  Furthermore, what we presume to be subtypes of ADHD (ADHD-HI and ADHD-C) may be viewed instead as two different developmental stages of the same disorder (Barkley, 1998).
     As ADHD children tend to progress at a relatively constant rate but with delays in both social development and cognitive tasks when compared to their non-ADHD peers, Mirsky, Pascualvaca, Duncan, and French (1999) speculate whether ADHD represents a developmental delay.  The authors point out that the hypothesis that this “developmental lag” does not necessarily mean that ADHD children will eventually catch-up with their peers is supported in the research literature.  In fact, follow-up studies indicate that approximately 70 to 80 percent of children diagnosed with ADHD continue to present symptoms of inattention and impulsivity into adolescence and early adulthood.  As it is likely that the developmental course and outcome of ADHD children depend on the specific nature of their attention deficits, the authors underscore the importance of assessing specific elements of attention (see Laboratory Measures). Although it is clear that “the diagnosis of ADHD is given to a group of children who show marked variability in their clinical presentation and response to treatment”, little is known about the possible differences in developmental trajectories and outcomes between ADHD subgroups.
    When assessing for ADHD, one must gather historical, behavioral, and socio-emotional information about an individual from multiple sources, informants and contexts.  Furthermore, as indicated in the DSM-IV-TR, it is critical that the evaluation team considers whether the child’s behaviors are developmentally inappropriate and that there is clear evidence of significant impairment in social and/or academic functioning.  Thus, reflected in the assessment process is a regard for the importance of the interactional nature of biological, environmental and developmental constituents.  Current objectives for refining assessment methods should emphasize the importance of developmentally sensitive measures.  At this time, behavior rating scales and some structured interview schedules seem to incorporate this aspect best because of their extensive normative base.
     Using CPTs and actigraphs, Inoue, Nadaoka, Oiji, Morioka, Totsuka, Kanbayashi, and Hukui (1998) considered the developmental perspective in the analysis of their findings.  Results suggest that younger elementary schoolchildren are more hyperactive, inattentive, and impulsive.  Therefore, the authors suggest that ADHD should be diagnosed taking into consideration the age of the child.
     Age and sex relationships were examined with measured performance in the CPT in a study by Lin, Hsiao, and Chen (1999).  The participants were 341 randomly selected school children between the ages of 6 and 15.  Results revealed that the hit rate, false alarm rate, and sensitivity of the CPT measures were associated with age.  These findings underscore that failing to take variables such as age and gender into consideration may result in misdiagnosis or misinterpretation of assessment results.
     Fisher, Barkley, Edelbrock, and Smallish (1990) studied various outcomes in adolescence of children diagnosed as hyperactive.  One hundred hyperactive children (aged 12-14 years) were tested on measures of academic skills, attention and impulse control, and select frontal lobe functions and, then, were tested in follow-up eight years later.  Follow-up results indicated that hyperactive subjects demonstrated impaired academic achievement, impaired attention and impulse control, and greater off-task, restless, and vocal behavior, compared with control subjects.  Thus, it was concluded that hyperactive children may remain chronically impaired in academic achievement, attention, and behavioral disinhibition well into their late adolescent years.
     Barkley (1997) addresses several problems in diagnosing ADHD across the lifespan using the DSM-IV items.  First he states that much of the content of the inattention items actually refers to the persistence of goal-directed responding and resistance to distraction (interference control).  He argues that the term inattention, is in many ways misleading, as distraction and impersistence have nothing to do with perception of information processing, which is usually associated with
attention.  A second argument is that the items reflecting poor behavioral inhibition are underrepresented relative to their importance in identifying the disorder.  Barkley notes that even though the symptoms of inattention become useful discriminators of ADHD in school-age children, they may become increasingly less useful by adulthood.  Thus, only the more serious cases of ADHD would be more likely to be detected by these inattention items, and, even then, not particularly well (Barkley, 1997).
     Barkley offers suggestions to address the problem of the developmental insensitivity of these assessment instruments, by doing what has already been done in the diagnosis of mental retardation or learning disabilities such as reading disorders.  Specifically, he proposes that a wide range of items must be used that represent the broad developmental span for the cognitive impairment of interest.  In addition, a flexible cutoff score must be chosen that is developmentally referenced in order to continue to reflect the same degree of deviance at all ages (Barkley, 1997).
     The developmental perspective is an essential piece in the assessment of ADHD as many of the symptoms tend to be subjective measures (i.e. difficulty sustaining attention, easily distracted, etc.) as evidenced by inconsistency between informants.  Furthermore, the history of its classification in the different versions of the DSM illustrates the inconsistencies and confusion in the agreement of ADHD.  In addition, failing to incorporate one’s developmental level in the assessment procedures may lead to misdiagnosis as measured by the DSM.
 

III. OPTIMAL ASSESSMENT BATTERY

     To date, ADHD, like any other mental disorder, cannot be firmly diagnosed by one medical or objective procedure (August, 1998).  The best approach for evaluating individuals for ADHD is a comprehensive, multi-method, multi-informant behavioral assessment that addresses the specific referral questions.  As a best-estimate approach, the following assessment strategies, also mentioned above, should be used in a standard ADHD assessment: Diagnostic interview, behavioral rating scale, behavioral observations, and laboratory measures that examine different elements of attention.  In addition, a peer sociometric measure may be of use if the child is having social difficulties.  Research has shown that many of the available methods do not correlate highly with one another, which lends support to the rationale for incorporating more than one method.
     The assessment practice of ADHD has included the use of diagnostic interviews, behavioral rating scales, peer-referenced measures, behavioral observations, and laboratory measures.  An undergirding theme in assessing for ADHD is the developmental perspective, which is a reflection of the developmental underpinnings associated with this disorder.  At the present time, it is recommended that measures that have a solid normative base such as that found in most behavioral rating scales and/or diagnostic interviews remain a necessary component of the broad assessment.  Currently, the most effective method for ADHD assessment is conducting a comprehensive behavioral assessment that utilizes multiple methods and informants.  While assessments may be conducted by school personnel and/or medical professionals in the school environment or clinical settings, it is imperative that these professionals and informants communicate and work together as an evaluation team to discuss the students’ situation. Furthermore, the evaluation team should discuss the confluence of assessment results as well as the developmental level of the child when attempting to interpret findings and make a diagnosis.  Failure to establish effective communication may result in misdiagnosis.
 
 

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I. TREATMENT

 A variety of interventions have attempted to ameliorate the cognitive, behavioral, academic and social disturbances, which accompany ADHD.  Among the most popular treatments are pharmacological, behavioral, cognitive-behavioral and multi-modal strategies.  All treatments have demonstrated some promise, but a single effective treatment has not been identified.  The heterogeneity of symptoms and frequent co-occurrence with other behavioral and psychological conditions contribute to the difficulty in treating ADHD.  Few studies have examined the efficacy of treatments across developmental stages.  Despite the evidence that various symptoms of the disorder seem to improve somewhat with age, psychologists know little about which treatments address the salient features of this disorder across different stages of the life span.  Listed below are examples of research literature, which examine the effectiveness and/or ineffectiveness of various treatment approaches that have been utilized for ADHD.

Studies of Pharmacotherapy for ADHD:

     Psychostimulants are one of the most common treatments for ADHD in children and include methylphenidate (MPH, also commonly known as Ritalin), clonidine, dextroamphetamine, and Adderall among the most commonly prescribed in the United States (Manos, Short, & Findling, 1999).  While several studies have demonstrated their effectiveness, the use of psychostimulants with children continues to be controversial.
     Little information exists concerning the long-term effects of psychostimulants, however, there is no conclusive evidence that careful therapeutic use is harmful (National Institute of Health, 1998).  Because the behavioral and side effects of stimulants can vary significantly across dosages and individuals, the importance of evaluating the medication response should be stressed (Roberts & DuPaul, 2000).  Evaluations should include repeated assessment of child behavior across dosages including placebo and/or non-medication conditions (as a basis of comparison) in order to ensure that the child is not receiving inappropriate dosages.
Despite its controversy, this type of treatment has been used in children as young as two years old.  Research has shown that clinical improvement in behavior occurs in as many as 75-92 percent of those with the hyperactive-impulsive form of ADHD and results in normalization of behavior in approximately 50-60 percent of these cases on average (Barkley, 1997).
      Studies have estimated that 3 percent of US schoolchildren take medication for ADHD, while as many as 7 percent of US children may have the disorder (Lang, 1997).  Recently, public concerns have been raised about the dramatic rise in ADHD diagnosis and stimulant prescription.  Jensen et al. (1999) investigated the rates of ADHD diagnosis and treatment in four U.S. communities (Atlanta, Georgia; New Haven, Connecticut; Westchester, New York; and San Juan, Puerto Rico).  The epidemiological procedures used for the study entailed two lay interviewers separately interviewing children (ages 9-17) and their primary caretakers in their homes using a computer-assisted version of the National Institute of Mental Health Diagnostic Interview Schedule for Children (NIMH-DISC-2.3). Only the children for whom the DISC data permitted an ADHD diagnosis were included in the analyses.  The researchers found a low overall prescription rate, only 12% of children with ADHD received stimulant treatment.  There were no significant differences in prescription rates between the four sites.  Although half of the children who were taking stimulants did not meet full diagnostic criteria for ADHD, this may have been a function of a positive response to stimulant treatment.  However, these children had high levels of ADHD symptoms.  The authors conclude that concerns about overprescription were not supported by the study data.  Furthermore, more ADHD children received school-based or psychotherapeutic services (one-fourth to one-third) than medication (one-eighth).  The authors underscore the lack of services provided to ADHD children, with these findings paralleling previous reports that only about one-third of children in need of mental health services actually receive care.
     LeFever, Dawson, and Morrow (1999) attempted to determine the extent of medication use for ADHD among children enrolled in public schools in two different cities in Virginia.  The study population included all students enrolled in grades 2 through 5 in city A (n=5767), and city B (n=23967).  Results indicated that 8-10 percent of the students received medication for ADHD.  The majority (90 percent) of children receiving medication were prescribed MPH, and 5 percent received MPH in combination with other drugs.  The percentage of students receiving ADHD medication generally increased with grade; the increase from second to fifth grade was from 7-9 percent and 7-10 percent in cities A and B respectively.  The percentage was highest in fifth grade, in which 18 percent and 20 percent received medication in cities A and B, respectively.  The study also included sex and race differences: 17 percent of Caucasian males, 9 percent of African-American males, 7 percent of Caucasian females, and 3 percent of African-American females received ADHD medication (these findings were consistent between the two districts).  The difference between the findings of this study and the previous study indicate that both overprescription and underprescription occur and are likely to be region-, community-, and provider-specific (Jensen et al, 1999).
      While the the LeFever, Dawson, and Morrow (1999) study included school-aged children, psychotropic medical use has also been studied in younger children.  Rappley, Mullan, Alvarez, Eneli, Wang, and Gardiner (1999) investigated the diagnosis and treatment methods used in very young children with ADHD.  Their study included 223 children aged 3 years or younger who had a clinical diagnosis of ADHD.  In addition, many had conditions commonly comorbid with ADHD (44 percent), other chronic health conditions (41 percent), and injuries (40 percent).  More than half of the children received psychotropic medication (57 percent) while 26 percent received psychological services.  Among those receiving psychotropic medications, 54 percent received one medication and 45 percent received a combination of medications.  Twenty-two different medications were used by children included in this sample, with MPH and clonidine hydrochloride among the most frequently used.  The authors do point out that, “the use of psychotropic medications as described for these children is not approved by the FDA” (Rappley, et.al., 1999).
 The research described previously highlights the prevalence of psychotropic medical use in children with ADHD.  We will now turn to studies that highlight different effects of such medications.
     One commonly reported side effect of psychostimulant use is sleeping difficulties.  Stein (1999) compared the parental perceptions of sleep problems in stimulant treated children with ADHD, untreated children with ADHD, and a control group children receiving routine pediatric care.  Thirty percent of the stimulant treated children with ADHD versus 10 percent of the untreated children with ADHD reported delayed sleep onset or insomnia every night.  The stimulant treated children with ADHD were three times more likely to report severe sleeping problems than the untreated children with ADHD.  The authors point out that the findings of this study concur with previous studies indicating that children with ADHD who take stimulant medications are at increased risk for insomnia as well as other sleeping difficulties.
     Schachar, Tannock, Cunningham, and Corkum (1997) studied the long-term effects of MPH in children’s behavior as well as the medication side effects as reported by teachers and parents.  The study duration was scheduled for 12 months, with this interim report covering the first four months of treatment.  The findings include differences in adherence to treatment, with more families and children in the placebo group discontinuing treatment due to ineffectiveness.  Medication side effects were the primary reason for discontinuing use in the medication group.  Teacher ratings revealed greater behavioral improvement for the MPH group.  In contrast, parents reported no difference between the groups (both groups improved overall).
     Another study included observations of student’s behavior and academic performance in response to the effectiveness of Adderall with ADHD children.  Swanson, Wigal, Greenhill, Browne, Waslik, Lerner, Williams, Flynn, Agler, Crowley, Finberg, Baren and Cantwell (1998) included 30 children in their study to compare the effectiveness of 5, 10, 15, and 20 mg of Adderall to the best dose of Ritalin.  Results indicated that all doses of the two medications were superior to the placebo.  However, higher doses of Adderall lasted longer than lower doses of Adderall and Ritalin, and these effects were apparent in the children’s behavior and academic performance.  This longer lasting effect is of particular interest because it has been reported that higher doses of Ritalin give a more powerful effect instead of a longer lasting effect.
     Another study was conducted comparing the effectiveness of MPH and Adderall in children ranging in age from 5 to 17 years.  More specifically, the study was designed to compare the effectiveness of Adderall given once in the morning and that of MPH given in the morning and at noon.  All forty-two participants met the DSM-IV criteria for ADHD and were assigned to one of three groups (Adderall, MPH and control).  Teacher reports, parent ratings as well as standardized measures of the side effects were included in the measurement procedures.  Results indicated that both MPH and Adderall are effective treatments as measured by the teacher and parent ratings of behavior.  In addition, a single-dose treatment of Adderall was shown to be as effective as two daily doses of MPH.  These results may increase the possibility of managing treatment without having to involve the school in medication administration.
     As the majority of stimulant response studies have been conducted on children, there is a paucity of studies examining stimulant efficacy for adolescents with ADH.  Barkley, Connor, and Kwasnik (2000) evaluated the utility of employing systematic assessment of stimulant response with adolescents (ages 12-17) with ADHD in a routine outpatient clinical setting.  Thirty-five teenagers with ADHD rotated through five blind drug conditions: Two daily doses of Adderall (5 mg and 10mg), MPH (5mg and 10mg), and a lactose placebo.  Results revealed no significant effects of the medication on parent or teacher ratings between groups.  The authors note confounding variables such as the teachers completing less than half of the weekly ratings across the five weeks of the study. Subjects taking 10mg of Adderall made significant improvements on an inhibition control task (Stroop Color Word Association Test) but not on an attention task (CPT).  Teens reported less severe side effects for the 10mg dose of Adderall than the 5mg dose of MPH.  Non-blinded global clinical judgements of stimulant response, based upon multiple sources of information, suggested that both Adderall (46%) and MPH (40%) appear to be clinically effective in the treatment of adolescents with ADHD.  However, 14% did not respond to either stimulant.  The authors discuss several logistical problems with conducting this type of study using rating scales in typical outpatient practice and offer recommendations (e.g., a daily report card presented to each teacher by the teenager) for future studies.
     Frankel, Cantwell, Myatt, and Feinberg (1999) used the Achenbach Child Behavior Checklist (CBCL), the Social Skills Rating System (SSRS), and the Piers-Harris Self-Concept Scale (PHS), to assess the self-esteem of children with ADHD medicated with stimulants and those who were unmedicated.  Results showed that stimulants were associated with significantly higher self-esteem and children reported feeling more intelligent and more popular than unmedicated children with ADHD did.  Significant correlations indicated that higher doses were associated with higher levels of self-esteem.  The authors highlighted two possible interpretations for these results.  First, subjects reported higher self-esteem because they perceived that their behavior was under better control (and perhaps they were drawing less criticism from others).  Second, the dose-response correlations reflect stronger internal sensations caused by stimulants at higher doses and perhaps a greater hope for positive social outcomes.
      Kemptom, Vance, Maruff, Luk, Costin, and Pantelis (1999) attempted to measure  executive function in medicated and non-medicated children with ADHD by using a computerized battery.  Results from the study indicated that the unmedicated ADHD children showed impairment on tasks of executive function, including planning ability, movement time, attentional set shifting, and spatial working memory.  However, the group of medicated ADHD children showed no impairment on any of the executive function tasks, with the exception of poor performance on the spatial recognition memory task.  Results from this study are consistent with neuropsychological attributes of ADHD in specific regions of the brain.
      Thomson and Varley (1998) conducted a multivariate analysis with several predictor variables (age, gender, SES, family structure type, adoptive status, and neurological status) and response to medication in 336 children with ADHD from 3-16 years old.  All children underwent a 3-week, double blind trial of MPH and a placebo.  Three conditions were assigned to each child: a) 1 week of placebo, b) 1 week of .5 mg/kg daily of MPH in two divided doses, and c) 1 week of 1.0 mg/kg daily of MPH in two divided doses.  The CBCL and the Wechsler Intelligence Scale for Children (WISC-R) were completed before the drug trial period.  In addition, the Connors Abbreviated Symptom Questionnaires- Parent and Teacher forms and narratives regarding the child’s functioning were collected daily during the medication trial for the determination of response.  Results indicate that neurologic status, inattention, and overactivity were found to be most likely to predict good response to psychostimulants, whether rated by parents or teachers.  Although a number of variables predicted a positive psychostimulant response, the strength of the predictive associations suggests only a minimal clinical usefulness.

Cognitive-Behavioral Therapy for ADHD:

       A variety of cognitive-behavioral interventions have been used to treat ADHD in children. Ervin, Bankert, and DuPaul (1996) discuss several of these methods including: Cognitive-based interventions (i.e., self-instruction training and social problem-solving training), contingency-based interventions (i.e., self-monitoring, self-evaluation, self-reinforcement, and correspondence training), and cognitive-behavioral therapy (self-management) combined with other interventions.  The authors use empirical studies to examine the e