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, Erin McNerney, Rosy Fredeen, and Lauren Brookman
University of California, Santa Barbara
Author Note: Shane R. Jimerson is a professor at UCSB and Erin McNerney, Rosy Fredeen, and Lauren Brookman are doctoral students. The authors would like to thank Mary Baker, and Katherine Elliot for their contribution to the content of this website, through their efforts on prelimary drafts.
Autistic Disorder
Autistic disorder has been described as “…
a severe form of psychopathology evidenced early in childhood and characterized
by severe, pervasive behavioral deficits and bizarre behavioral patterns.”
(Schreibman & Charlop-Christy, 1998; p. 157). The features of
autism include an impaired development in social interactions and communications,
and restricted repertoire of interests. The characteristics of autism
vary greatly across individuals, and individuals diagnosed with autism
do not need to display all of the characteristics (Koegel & Koegel,
1995; Travis & Sigman, 2000). Severity of symptoms of autism fall along
a “spectrum.” In many cases there is an associated diagnosis of mental
retardation. Long term outcome for individuals with autism varies
greatly, depending on the effectiveness of interventions utilized and degree
of impairment. Special and general educators are a group of professionals
who can impact the long term outcomes for children with autism through
intervention and education.
Promoting the success of all students, including
those with disabilities, is the ultimate goal in education. Because
recent epidemiological research suggests a large increase in the incidence
of autism (Bristol-Powers, 1999) and students with disabilities are increasingly
placed in full-inclusion settings, general educators are increasingly likely
to encounter children with autism throughout their careers. Recent
estimates suggest that nearly 400,000 people in the US have some form of
the disorder, thus autism is the third most common developmental disability
(it is more common than Down syndrome). Thus, it is essential that
school psychologists and other educational professionals have up-to-date
information regarding autism. Considering that this disorder impacts
multiple domains of a child’s development over time, the field of developmental
psychopathology provides a useful framework and salient research addressing
the epidemiology, etiology, assessment, and treatment of children with
autism.
DSM-IV Criteria for Autistic Disorder
A. A total of six (or more) items from (1), (2), and (3) with at least two from (1) and one each from (2) and (3):
(1) Qualitative impairment in social interaction, as manifested by at least two of the following:
(a) marked impairment in the use of multiple nonverbal behaviors such
as eye-to-eye gaze, facial expression, body postures, and gestures to regulate
social interaction
(b) failure to develop peer relationships appropriate to developmental
level
(c) a lack of spontaneous seeking to share enjoyment, interests, or
achievements with other people (e.g., by a lack of showing, bringing, or
pointing out objects of interest)
(d) lack of social or emotional reciprocity
(2) Qualitative impairments in communication as manifested by at least one of the following:
(a) delay in or total lack of the development of spoken language (not
accompanied by an attempt to compensate through alternative modes of communication
such as gesture or mime)
(b) in individuals with adequate speech, marked impairment in the ability
to initiate or sustain a conversation with others
(c)stereotyped and repetitive use of language or idiosyncratic language
(d) lack of varied, spontaneous make-believe play or social imitative
play appropriate to developmental level
(3) restricted, repetitive and stereotyped patterns of behavior, interests, and activities as manifested by at least one of the following:
(a) encompassing preoccupation with one or more stereotyped and restricted
patterns of interest that is abnormal either in intensity or focus
(b) apparently inflexible adherence to specific, nonfunctional routines
and rituals
(c)stereotyped and repetitive motor mannerisms (e.g., hand or finger
flapping or twisting, or complex whole-body movements)
(d) persistent preoccupation with parts of objects
B. Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years: (1) social interaction, (2) language as used in social communication, or (3) symbolic or imaginative play.
C. The disturbance is not better accounted for by Rhett’s Disorder or Childhood Disintegrative Disorder.
Source. American Psychiatric Association. (2000). Diagnostic and statistical
manual of mental disorders (4th ed., text revision p. 75). Washington,
DC: Author.
Epidemiological Information
In 1943, Leo Kanner first used the term “autism”
to describe a group of children who shared some similar characteristics,
but who did not seem to fall under the classification of “childhood psychosis”.
In 1980, the condition was first included in the Diagnostic and Statistical
Manual, third edition (DSM-III) as “Infantile Autism,” in the category
of pervasive developmental disorders (American Psychiatric Association,
1980). “Autistic Disorder” is the contemporary classification term
used in both the DSM-IV (American Psychiatric Association, 1994) and DSM-IV-TR
(American Psychiatric Association, 2000) which . Diagnostic criteria currently
includes impaired social functioning and communication, and restricted,
repetitive and stereotyped patterns of behavior, interests, and activities
(see DSM-IV-TR criteria in Table 1).
Autism is currently conceptualized as a spectrum
disorder, with individuals exhibiting diverse and heterogeneous symptoms.
In addition, the manifestation of children’s social and behavioral deficits
may change over time, across environments, and range on a continuum from
mild to severe (Koegel & Koegel, 1995). Extant literature has typically
described autistic disorder as occurring in one of every 20,000 individuals.
However, the median rate of autism is 5 cases per 10,000 individuals, with
reported rates ranging from 2 to 20 cases per 10,000 individuals (American
Psychiatric Association, 2000). It has been argued that the differences
found in prevalence rates may be based on the criteria used to classify
children. The definition of autistic disorder has changed over time, especially
as new and revised versions of the DSM and ICD classification systems are
used. Specifically, the higher prevalence rates may be a result of
better detection of autism and the broadening of the definition of autism
over the years (Gillberg & Wing, 1999; Wicks-Nelson & Israel, 1997).
Females are four to five times more likely than males to receive a diagnosis
of autism (American Psychiatric Association, 2000).
Recently, Powell, Edwards, Edwards, Pandit,
Sungum-Paliwal, & Whitehouse (2000) studied the changes incidence rates
of autism in two regions of the United Kingdom between 1991 and 1996.
Both classical childhood autism and other autism spectrum disorders were
studied. Cases of autism or autism spectrum disorders were detected
from examination of records of child development centers and a regional
child psychiatric referral center. Results show that the male to
female ratio was 6:1. The incidence rate per 10,000 children per year was
8.3 for all children with autism spectrum disorders, 3.5 for classical
autism, and 4.8 for other autism spectrum disorders. Rates
for classical autism increased by 18% per year and rates for other autism
spectrum disorders increased by 55% per year. The authors conclude
that clinicians are becoming increasingly willing and able to diagnose
autism spectrum disorders in preschool children. The authors also
argue that incidence rates are more sensitive to underlying changes in
disorder risk than prevalence rates. They explain that prevalence
studies are confounded by an absence of information about the type of statistic
used.
Tanguay (2000) summarized recent advances
about the nature, diagnosis and treatment of pervasive developmental disorders
and estimate the prevalence of autism to be 1 per 2000. Reviews of
epidemiological studies of autism cite an increase in prevalence reported
in the literature. The author found that comparing studies in the
past decade shows that they differ greatly in screening methods, diagnostic
instruments, and diagnostic criteria. He cites these as possible
explanations for differing results. The author concludes that the
apparent increase in the prevalence of autism is that higher rates include
varying members of persons with atypical autism, ASP, and PDD-NOS as well
as autism.
Gillberg and Wing (1999) reviewed all English language
articles ever published on the prevalence of autism to examine if there
has been a real increase in autism prevalence. Results indicate that early
studies, from the 1960's and 1970's, contained prevalence rates of under
0.5 in 1000 children, whereas, later studies from the 1980's to the present,
contained a mean rate of approximately 1 in 1000 children. Interestingly,
the only two U.S.A. studies published on autism prevalence (1987 and 1989)
reported atypically low rates, with prevalence being estimated at 3.4 in
every 10,000 individuals. The authors provide several suggestions for the
increase in autism prevalence. First, they suggest that using Kanner’s
original criteria immediately provides significantly lower prevalence rates
than if the DSM or ICD criteria are used. Secondly, Gillberg and Wing consider
the possibility that the rise is simply due to greater autism awareness
and that prevalence has always been higher than earlier studies reported.
The authors also contend that the increase in rates might be spurious because
most studies were conducted on small populations. In conclusion, Gillberg
and Wing state that their review of prevalence studies does not resolve
the question of whether or not the increase in autism is real or if it
mainly reflects our ability to better detect the condition. Nevertheless,
they do argue that a more reasonable and conservative prevalence estimate
of autism is 1 in every 1000 children.
Autistic disorder is sometimes observed in
association with other neurological or medical conditions, such as encephalitis,
phenylketonuria, tuberous sclerosis, fragile X syndrome, anoxia during
birth, and maternal rubella. As many as 25% of individuals diagnosed with
autistic disorder may develop seizures, often with increase in age. Children
with autism also often have great difficulty with learning. In about half
of all cases, there is an associated diagnosis of Mental Retardation commonly
in the moderate range (IQ 35-50). Approximately 50-60% of all children
with autism function in the moderate range of mental retardation.
Matsuishi and colleagues (1999) examined the
prevalence rates of autistic disorder and cerebral palsy in a neonatal
intensive care unit in Japan. A total of 5,271 neonates and 241 normal
controls were followed neurodevelopmentally at 2, 3, and 5 years of age.
Of the 5,271 neonates, 18 children were later identified as having autistic
disorder. The study yielded a prevalence rate of autistic disorder of 34
in 10,000, a rate that was two times higher than the previously reported
prevalence in Japan. The authors report that the children with autistic
disorder had a significantly higher incidence of meconium aspiration syndrome,
which is associated with fetal hypoxia, when compared to the children in
the control group. The authors suggest a possible connection between meconium
aspiration syndrome and development of autism. They recommend future research
be conducted examining this possibility.
Barton and Volkmar (1998) address the controversy
surrounding the incidence and contribution of less clearly related medical
conditions in the etiology of autism. Two divergent views are discussed;
one view claims that up to 30% of cases of autism are associated with a
known medical condition, while the second view claims that the incidence
is closer to 10%. The authors also address diagnostic criteria used to
identify autism, and discuss differing amounts of stringency used in past
studies. In the present article, the authors utilize a retrospective study
to determine the prevalence of associated medical conditions and the resulting
variability based on the systems used to diagnose autism. Criteria used
to diagnose autism were based on either the DSM-III or the DSM-III-R, and
data on medical conditions were obtained. The authors conclude that differences
in findings of previous research may be the result of the diagnostic system
employed, and which medical conditions are considered significant in the
etiology of autism. Specifically, the broader diagnostic criteria typically
results in the over diagnosis of autism, particularly among those more
severely disabled. Furthermore, it is among more severely disabled individuals
that more medical conditions are found.
In the article by Bristol and colleagues (1996),
a panel of distinguished scientists was interviewed for their opinions
regarding current developments in the study of autism and directions for
future research. Presented in question-answer format, this review summarizes
research and presents relevant topics for future study not only in epidemiology,
but also in related areas such as diagnosis, etiology, and intervention.
Estimates of prevalence are provided, and current epidemiological research
is described and the benefits of continuing research in epidemiology are
delineated. While this article does not provide an in depth analysis of
epidemiological issues, it is informative in that, as its title suggests,
it presents the “state of the science” in a concise format.
Bryson (1996) presents a brief review of the
results of epidemiological studies on autism as well as directions for
further research. The author provides current estimates of prevalence and
describes the effects of changes in the DSM-IV classification on epidemiological
estimates. The author also identifies ways in which future epidemiological
studies may be used to illuminate issues pertaining to treatment and etiology.
In 1996, Nordin and Gillberg, reported prevalence
rates of autistic spectrum disorder in a population of children with mental
retardation and motor disabilities in Sweden. The authors used a rigorous
diagnostic system to diagnose children with three subgroups of autism spectrum
disorder: autistic disorder (those who met 8 of the DSM III-R criteria),
autistic-like condition (those who met 6 of the DSM III-R criteria), and
autism spectrum disorder not otherwise specified (those who had autistic
symptomatology but did not present symptoms with enough severity for the
DSM III-R classification). The study procedures entailed an initial period
of screening in 1991 and a follow-up screening in 1993. The results indicate
that autistic disorder is present in 8.9% of mentally retarded children.
In addition, they found that it is more prevalent in severely retarded
children than in moderately or mildly retarded children. Finally, they
found that 60% of children with autistic disorder had medical and neurological
disorders.
Ritvo and colleagues (1990) illustrate one
of the primary purposes of epidemiological studies: to contribute to our
understanding of the etiology of disorders. The authors report on the results
of an epidemiological survey of autism in Utah with particular emphasis
of the existence of medical disorders in the autistic population. Specifically,
the results indicate that the diseases known to produce pathology in the
central nervous system are more prevalent in autistic populations. These
diseases include: viral and bacterial infections, metabolic disorders,
and chromosome and genetic abnormalities. The authors conclude that the
results support the hypothesis that autism is caused by central nervous
system abnormalities which are in turn, caused by disease.
Schreibman and Stahmer (1993) present a comprehensive
description of autistic disorder as well as a brief review of issues concerning
diagnosis, assessment, etiology, and treatment. The authors provide relevant
information particularly in the areas of differential diagnosis and the
relative effectiveness of different treatment paradigms. It identifies
and presents several examples of several behaviors typically seen in autistic
children and differentiates these from those typically seen in children
with schizophrenia, pervasive developmental disorder, developmental aphasia,
and mental retardation. In addition, the authors critique different approaches
in behavioral therapy, pharmacotherapy, and alternative treatments citing
empirical studies. Finally, a case study elucidates the practical application
of a treatment program, pivotal response treatment.
Sponheim and Skjeldal (1998) investigated
the prevalence of autism in a sample of Norwegian children (aged 3-14 years)
in order to compare the rate with other findings suggesting prevalence
rates of up to 13.9 cases per 10,000. The authors state that the inclusion
of atypical autistic disorders increase definitions of autism, as well
as prevalence rates. The authors based diagnosis of autistic disorder on
ICD-10 criteria (DSM-III-R diagnosis were also coded). The prevalence of
childhood autism was estimated to be 4-5 per 10,000 in the Norwegian population-based
study, and did not confirm the higher estimates recently reported. The
authors conclude that differences in diagnostic criteria and differences
of the target populations most likely account for the discrepancy between
studies of prevalence. This article provides evidence contrary to the trend
of increase in prevalence of autism, however, the authors state that they
did not include individuals with “atypical” autistic features (e.g. Asperger’s
syndrome).
In conclusion, autism is a disorder that continues
to pose challenges to the scientific community. It is a condition characterized
by both deficits, and excesses in normal development. Because of the pervasive
nature of these deficits and excesses and the controversy over a cure,
autism has stimulated much research in child psychopathology. Epidemiological
studies have served to refine the criteria for diagnosing autism and differentiating
it from disorders with similar symptomatology. Epidemiological research
has also done much to further our knowledge regarding the possible etiologic
role of genetic factors and medical disorders. The heterogeneity of the
population of children with autistic disorder revealed in epidemiological
data suggests that there is a host of risk factors implicated in the development
of autism. In addition, current epidemiological research suggests a significant
increase in the prevalence of autism. Reasons for this increase
include changes in diagnostic criteria and increased awareness of autism
and autism spectrum disorders. Future epidemiological research will continue
to enhance our understanding of the prevalence of autism and the contribution
of potential risk factors.
I. ETIOLOGY
Researchers in the medical and psychological fields have been trying to find the cause (or causes) of autism since it was first identified in 1943. Nevertheless, the specific etiology of autism continues to baffle the scientific community. Currently, most researchers and practitioners view the etiology of autism as being multifaceted, resulting from the interplay of genetic, neurological, and environmental factors. Research in genetics has revealed that several genes may be involved in the susceptibility to autism. Epidemiological studies suggest that in addition to a genetic predisposition, exposure to viral infections prenatally may cause the neurological abnormalities which result in autistic behaviors. There is an abundance of literature examining suspected neurological abnormalities in autism. Some researchers have suggested that the abnormal neurological structure of some children with autism may be due to disrupted development of neurons in the cerebellum and limbic system. In addition, evidence found in several studies of abnormal levels of serotonin in individuals with autism suggests that serotonin plays a role in the development of autism. More recent studies (reviewed below) examine the contributions of genetics and neurobiology in the development of autism.
Genetic and Neurobiological:
Rutter (2000) reviews the genetic studies of
autism from the 1970s to present day elaborating on the advances in the
understanding of the role of genetic influences in autism. Specifically,
autism appears to be influenced by the operation of several interacting
genes. He summarized twin studies, family studies, fragile X, and
genetic heterogeneity. The author cites the findings that 90% of
monozygotic twin pairs were concordant for mixtures of social and cognitive
deficits qualitatively similar to those found in autism. Thus, the
author calls for the need for quantitative genetic studies that look at
the broader phenotypes of autism, concluding that the identification of
causal processes could lead to effect means of prevention or intervention.
In a recent article, Trottier, Srivasta and
Walker (1999) present a review of recent genetic and neurobiological research
studying the etiology of autism. The authors begin by acknowledging that
the
etiology of autism is extremely complex and that in most cases, the underlying
pathologic mechanisms are not known. However, based on family and twin
studies, there seems to be a genetic basis for autism. Interestingly, the
authors report that a quarter of all autism cases are associated with genetic
disorders or infectious disorders. On the other hand, neurochemistry studies
have revealed altered levels of such neurotransmitters as serotonin, epinephrine,
and norepinephrine in autism. After reviewing the recent etiological studies
in genetics, neurobiology and neurochemistry, the authors conclude that
autism is best conceptualized as a “convergent behavioral manifestation
of various brain dysfunctions with different causes” (112).
Konstantareas and Homatidis (1999) present
the results of their record examination of 127 children diagnosed with
autism over a seven year period. Of the 127 participants, 28 children had
karyotypes performed. (Karyotypes involve identifying the chromosomal characteristics
of a particular cell.) Eight children were found to have abnormal karyotypes
with chromosomal abnormalities (e.g., breakage, a 47 XY pattern, trisomy
13, inversion-duplication of chromosome 15). Even though the children with
abnormalities were more cognitively delayed, they were not rated as being
more severely autistic. Despite limitations, such as not having karyotypes
conducted on all the children, the results of the study are consistent
with previous rate estimations of abnormalities. The authors suggest that
future research examining this issue be conducted more systematically.
Lauritsen and colleagues (1999) recognize
that autism is a heterogeneous disorder with a currently unknown etiology,
however, these authors also examined chromosomal abnormalities associated
with autism. The authors used the Danish Cytogenetic Central Register to
detect possible autosomal chromosome abnormalities associated with autism.
In addition, the authors reviewed the literature for reported cases of
autism associated with chromosomal abnormalities to see if they could identify
any potential candidate chromosomal regions. The study revealed potential
candidate regions on chromosomes (i.e. 7q21 and 10q21.2). Interestingly,
these two candidate regions had not been previously reported. The literature
review also revealed possible candidate regions on other chromosomes (i.e.
16q23 and 17q11.2).
Folstein and colleagues (1998) discuss the
idea that while autism appears to be genetic, it may be difficult to identify
the genes that contribute to the disorder. It is hypothesized that several
genes may be involved, most likely 2 to 4 genes, but possibly as many as
10. A number of strategies are described in attempting to identify these
genes and how they interact to produce a particular phenotype. Advantages
and limitations are addressed using family structures such as affected
sibling pairs, more distantly related family members, and discordant sibling
pairs. The authors also discuss future directions, such as the frequency
of the marked genes in autism population, and whether certain marked genes
appear more frequently in individuals with a particular autism phenotype
(e.g., nonverbal, or those who have seizures). The authors conclude that
a variety of different types of family structures, phenotype characteristics,
and analytic approaches will most likely need to be combined in order to
identify specific chromosomal areas likely to contain the contributing
genes.
Rapin and Katzman (1998) provide a clear and
concise review of diagnostic issues, prevalence and etiology of autism.
The authors state that while autism has multiple causes, genetics plays
a major role. The article discusses that autism is a behaviorally defined
syndrome, with a complex etiology, and not much is currently known about
its pathological basis. In a few cases, autism is associated with easily
diagnosable genetic and nongenetic conditions such as congenital rubella
or tuberous sclerosis, however, none of these conditions is invariably
the cause of autism. Epidemiological data suggests that environmental factors,
such as perinatal insults, play a small etiological role. In contrast,
genetics, or genetic vulnerability to some environmental factors may be
predominant in most cases. Various results from magnetic resonance imaging
(MRI) studies on individuals with autism are discussed, although the authors
state that, in terms of neuropathology, fewer than 35 brains have been
examined, thus conclusions are limited. In terms of chemical pathology,
current biochemical evidence is at best “speculative, weak, and contradictory”.
One of the more reliable findings appears to be elevated levels of serotonin
in the blood of about 25% of individuals with autism, although correlations
with brain levels of serotonin remain unclear. The authors also discuss
what is currently known regarding gene-environment interactions. Searches
for potential gene linkages in multiplex families with autism are currently
underway in several locations. The pattern of inheritance varies among
families, yet in one study, 10 out of 11 cases appeared to have paternal
inheritance.
Cook (1996) provides an explanation of the
mechanisms through which neurochemistry may affect the maturation process
of neural systems in autism. Although research has not yet established
a causal model for deficits in autism, this study delineates the several
methods of research which may aid researchers reaching this goal. Specifically,
the authors advocate collaboration between study in animal models, pharmacology,
neuroimaging, genetics and neurochemistry. This article is particularly
useful in that it explains the complex neural events implicated in the
process of the development of autism.
Minshew (1996) reviews the current goals of
research in neurobiology of autism. Evidence for functional and structural
abnormalities associated with autism are reviewed, and the author concludes
with a summary of the events at the neuronal level which produce functional
impairment in cognition exhibited in people with autism. The article is
particularly useful in that it provides a short explanation of the etiology
of autism which integrates knowledge on genetic, developmental, and neurochemical
approaches. In conclusion, the author identifies the need to examine and
locate underdeveloped neural systems and the relevance of this information
for formulating a neurochemical treatment that could be administered prenatally.
Through a comprehensive literature review,
Ciaranello and Cirananello (1995) identify factors which have been implicated
consistently in the development of autism. A review of family studies,
twin studies, studies of related disorders, and studies on neuropathology
provide evidences for both non-genetic and genetic causes of autism. The
primary non-genetic etiologic factor involved in the studies indicates
that autism may be inherited in a multifactorial, heterogeneous fashion.
The association of autism to other disorders having genetic causes such
as Fragile X syndrome and tuberous sclerosis supports the role of genetic
factors in the etiology of autism. Finally, the author’s examination of
evidence for neurochemical bases for autism reveals a consistent association
only with abnormal serotonin levels. The authors provide a comprehensive
review of the areas that have been researched and identify those that have
provided most consistent and fruitful results.
Neuroanatomical:
Page (2000) presents a review of evidence for
metabolic etiologies in autism spectrum disorders. One example given
is that of the relationship between gastrointestinal abnormalities and
autism spectrum disorder. Several enzyme defects are associated with classic
autism. The author points out that not everyone who has these
enzyme defects also has autism. He speculates that it is unlikely that
autism will prove to be a purely metabolic disorder. It is more likely
that different metabolic defects cause a common defect in neural circuitry
that is responsible for autism. The author cites studies that have
found some studies of metabolic treatments that can be highly effective
in some cases. The author suggested that research on the metabolic
aspects of autism of suffering from small study populations, limited scope
and lack of follow-up studies, was limited to one type of test, and having
found a subpopulation that differs from the normal. The author concludes
that the situation in metabolic autism appears to be a large number of
different gene defects, each with relatively small number of affected individuals.
DeLong (1999) proposes that 2 distinct forms
of autism exist. The first form is associated with bilateral brain damage
which occurs in early life, involving the temporal lobes and the medial
temporal lobes. This bilateral brain damage prevents the development of
fundamental semantic language structure, social skills, and organized purposeful
activity. Children with this form of autism cannot build a “structure of
meaning” and are low functioning. The second form of autism is a “more
common idiopathic form”. Specifically, the author hypothesizes that this
second form of autism is a result of familial affective psychopathology.
Supposedly, children with this form of autism are higher functioning and
are able to develop some language. The author uses a variety of genetic,
neurological and family studies to support his hypothesis.
Voeller (1996) suggests that socioemotional
impairments exhibited in autism may be due to an inability to process
information from three major channels: auditory vocal, visual-facial-gestural,
and gaze system. Research on humans and nonhuman primates with lesions
is cited to propose localization of deficits in these channels in the temporal
lobe, amygdala, and hippocampus. Interestingly, the author links these
deficits to the deficiencies in awareness of other’s emotions (or theory
of mind). He proposes that the neuronal abnormalities lead to impaired
ability to perceive and learn from socioemotional environmental cues. The
association of the neurobiological base with this specific behavioral difficulty
is an insightful integration of two different fields of study in autism.
II. DEVELOPMENTAL PERSPECTIVE
A developmental perspective views disorders
as developing from an interplay of various factors, including genetics,
environment, and previous experience. This model suggests that disorders
do not have a single cause but are instead a product of a process. Most
researchers would agree that there is no single cause for autism. While
family and twin studies indicate that there is a genetic component, they
also reveal that there are environmental factors involved as well. Relevant
developmental events implicated in autism occur primarily in the stages
of early neural development. It seems likely that normal growth of neurons
is inhibited during fetal development by a combination of factors which
may include genetic susceptibility and exposure to virus or toxins. At
present, many neural systems have been implicated in the development of
autistic symptomatology. The influence of developmental factors may be
examined in terms of development of specific deficits.
Rutter (1987) suggested that language difficulties
in autism may be in part due to an inability to process feedback from others.
Many of the language difficulties noted in children with autism, such as
pronominal reversal, are common in young children. The failure of autistic
children to acquire the language skills may be due to an inability to perceive
environmental cues. Voeller (1996) suggests that the socioemotional deficits
characteristic of autism may be caused by deficient neural systems underlying
responsiveness to social learning experiences. In other words, infants
with autism do not have the neuronal system development necessary to process
information from the environment that is essential for the development
of social cognition. Impairments in the development of social cognition
in turn may lead to the lack of awareness of other’s emotions. This lack
of awareness which has often been termed a deficit in the individual’s
“theory of mind” leads to the socioemotional impairments evidenced in individuals
with autism. Until more conclusive research is conducted and leads to the
identification of specific genetic and neural abnormalities in the
etiology of autism, a model based on the transactional interplay between
genetics, neurology and environment best explains the etiology of autism.
III. ETIOLOGY CONCLUSIONS
A review of the literature on the etiology
of autism clearly illustrates the complexity of this issue. Despite the
multitude of research exploring the etiology of autism, definitive conclusions
about this disorder remain elusive. A problem of particular importance
relates to the wide range of manifestations of autism symptomatology.
Two children diagnosed as having autism may share few characteristics.
Therefore, conclusive research on one cause for autism is nearly impossible,
as different causes may lead to a variety of symptoms. The most optimal
explanation for the etiology of autism is provided in a multifaceted model
which includes genetics, neurobiological, and neuroanatomical components.
Current research is moving toward the goal of integrating findings of several
approaches, however, more research must be done to clarify the nature of
the interplay between factors causing autism.
I. ASSESSMENT
While autism has been established as a developmental
disorder, the boundaries of the syndrome remain a subject for debate. As
the disorder varies in terms of its severity and symptomatology, assessment
and diagnosis of autism is not always clear cut. Early attempts to define
autism used categorical methods (Rutter, 1978). In the DSM-III (American
Psychiatric Association, 1980), autism was given diagnostic status for
the first time. The DSM-III-R (American Psychiatric Association, 1987),
DMS-IV (American Psychiatric Association, 1994), and ICD-10 also
include categorical diagnostic criteria for autistic disorder. The DSM-IV
divides the diagnostic criteria into what has been called the “triad of
impairment” (Wing & Gould, 1979). These impairments include deficits
in 1) social interaction, 2) verbal and nonverbal communication, and 3)
a restricted repertoire of activities and interests.
Snell and Brown (2000) indicate that assessments
are used to provide information for the purpose of screening, diagnosis,
student evaluation, placement, and curriculum development. As an alternative,
and often as a supplement to categorical diagnoses, a dimensional approach
to assessment of autism can be used. This involves the use of various diagnostic
instruments, rating scales, and diagnostic checklists pertaining to autistic
disorder. Deficits in the three main areas that characterize autism can
be measured with a variety of dimensional assessments. More importantly,
deficits in the “triad of impairment” can be affected by many other factors,
other than the presence of autistic disorder. The use of multidimensional
scales has an advantage over categorical diagnoses as they provide separate
documentation of deficits in the three main areas. Having separate scores
in the three areas that comprise DSM-IV and ICD-10 criteria allows confirmation
that an individual has a specific pattern of deficits defined as autism
(Volkmar, 1998). The following recent studies review important information
about the assessment process in autism.
Dimensional Assessment
According to Baranek (1999), one concern about
the assessment of autism is that diagnosis prior to 2 or 3 years of age
is extremely difficult to obtain, despite the fact that autism is believed
to be present from birth. The author suggests that earlier diagnosis is
currently limited because of two factors: 1) a lack of knowledge about
early development in infants who are later diagnosed as having autism,
and 2) reliance on conventional systems of classification which are based
on the “triad of impairment” (e.g., language, social and behavioral symptoms).
Baranek’s study examined the usefulness of both sensory-motor and social
behavior measures as early predictors of autism in infants. Home videos
of children when they were between 9 and 12 months of age were coded for
categories of sensory-motor and social behaviors (i.e., affect, anticipatory
postures, looking, response to name, motor and object stereotypes, social
touch and sensory modulation). The home videos came from three groups of
children who were either autistic, developmentally disabled, or typically
developing. The results of the retrospective study revealed that nine behavior
items in combination provided discrimination of the 3 groups and resulted
in correct classification 93.75% of the time. The predictor items also
accurately discriminated between the groups of children with autism and
developmental disabilities with a correct classification rate of 95%.
The most salient predictor variables for children with autism included
mouthing of objects, orientation to visual stimuli, social touch aversions,
unusual posturing, affect rating, and number of name prompts. In
conclusion, the author strongly suggests the use of sensory-processing
and sensory-motor variables in addition to social responses in assessment
procedures for autism.
Werner, Dawson, Osterling, and Dinno (2000)
recently performed a follow-up study to a previous study that compared
videotapes of children’s first birthday. Segments were scores on
the same three areas as in the previous study. Unlike the previous
study of 1 year olds, the groups of 8-10 month olds did not differ significantly
in the three generally categories (social behaviors, communication behaviors,
or repetitive behaviors). When the three children whose parents reported
late-onset autism were removed from the analyses, a significant main effect
for diagnostic group was found for the category of social behaviors.
The authors conclude that this finding may suggest that a significant variation
in the early developmental course of autism. Upon analysis of behaviors
within the categories, the most significant difference between typically
developing infants and infants with autism was orienting to their names.
Based on the results of both of these studies, this behavior seems to be
an early emerging and enduring characteristic of children with autism spectrum
disorder. The authors also hypothesize that the reason that they
did not find differences in the three domains that were found with 1 year
olds is because complex behaviors in the categories such as the use of
joint attention and communicative verbalizations are not solidly in place
until at least age 1.
Carter and colleagues (1998) examine special
population norms for four groups of individuals with autism: 1) nonverbal
children under 10 years of age, 2) children with some verbal skills under
10 years of age, 3) nonverbal individuals 10 years of age or older, and
4) individuals with some verbal skills 10 years of age or older. The assessment
of adaptive behavior in individuals with autism has traditionally been
used along with standardized measures of intellectual functioning to determine
the presence of mental retardation. In order to maximize the clinical utility
of the assessment of adaptive behavior for individuals with autism, the
authors provide supplemental norms for these individuals, thus clinicians
and researchers can compare adaptive functioning with a peer group of similarly
affected individuals as well as to national normative data. This article
is useful, as individuals with autism previously could only be compared
to individuals who were typically developing, or to disabled individuals
not classified with autistic disorder. The results indicate that, consistent
with previous research, individuals with autism demonstrate a unique profile
of adaptive behavior scores across the domains of the Vineland Adaptive
Behavior Composite. The addition of these norms should assist in the evaluation
of those with autism, providing a more proximal point of reference and
facilitating realistic recommendations for intervention.
In addition, Pilowski and colleagues (1998)
focused on comparing different systems used for diagnosing autism. The
diagnostic instruments differed in the role of the clinician (e.g., observer,
interviewer), the informer who supplied the information (e.g., parent,
teacher), and the way in which the information was collected (e.g., interview,
checklist, observation). The authors compared two assessments commonly
used to diagnose autism, the Autism Diagnostic Interview-Revised (ADI-R)
and the Childhood Autism Rating Scale (CARS). The former is an interview
conducted with the primary caregiver of the child with autism, typically
a parent. The latter assessment is a rating scale that is often filled
out by the clinician or teacher of the child with autism. In addition,
as gender differences in the incidence of autism have been reported, the
authors examined and compared the clinical picture of autism for a matched
sample of males and females suspected of having autism. As assessment often
relies on multiple informants, this study provides a measure of agreement
between two commonly used assessments. The results of the study show an
agreement of 85.7% between the two assessments. In addition, consistent
with previous literature, females had lower mental ages compared to males,
although no other demographic differences between the genders were found.
Filipeck and colleagues (1999) from the Child
Neurology Society, American Academy of Neurology, and 4 parent and 9 professional
organizations in liaison with the National Institutes of Health systematically
analyzed over 2,500 scientific articles to determine practice parameters
for the screening and diagnosis of autism. The conclusion the panel
reached was that appropriate assessment and diagnosis of autism demands
a dual-level approach. The first level involves routine developmental surveillance.
The panel made several recommendations for Level 1, including the following:
1) all early child care professionals, including physicians, psychologists,
and language pathologists, must become familiar with the signs and symptoms
of autism; 2) developmental screening should be conducted at each “well-child
visit throughout infancy, toddlerhood, and the preschool years”; 3) screening
tools, such as the Ages and Stages Questionnaire (ASQ), The Child Development
Inventories (CDIs), and the Parent’s Evaluation of Developmental Status
(PEDS) should be used to identify any parental concerns about their child’s
development; 4) health care professionals need to increase their ability
and comfort level in talking to families about autism; and 5) as mandated
by IDEA (1997) referrals for early intervention need to be initiated by
primary care physicians.
The second level discussed by the panel is
diagnosis and evaluation of autism. The following recommendations were
made for Level 2: 1) evaluation and diagnosis for autism needs to be conducted
by professionals who specialize in the treatment of autism; 2) diagnosis
of autism needs to be based on clinical (i.e., direct observations of social,
communicative and play behavior, and interviews) and DSM-IV criteria; 3)
children with milder forms of autism need to receive adequate and appropriate
assessments and diagnoses; 4) medical, neurological, family history, speech-language,
cognitive, psychological, adaptive functioning, and behavioral assessments
and evaluations must be conducted and collected by qualified professionals.
Both Level 1 and Level 2 and their specific recommendations are
intended to improve the assessment and diagnosis process of autism, and
as a result, lead to earlier intervention.
Diagnostic Tools
A variety of assessment instruments used to
diagnose and evaluate autism exist, including observation schedules, interviews,
checklists, and behavior rating scales. The following is a brief list of
some of the most commonly used assessments instruments used in autism:
Table 1: Assessment of Austism
Assessment Reference
Autism Diagnostic Interview-Revised (ADI-R) Lord, Rutter & Le Couteur,
1994
Childhood Autism Rating Scale (CARS) Schopler, Reichler, & Renner,
1988
Autism Diagnostic Observation Schedule (ADOS) Lord, Rutter, Goode,
Heemsbergen, Jordan, Mawhood & Schopler, 1989
[Prelinguistic Autism Diagnostic Observation Schedule (PL-ADOS) DiLavore,
Lord & Rutter, 1995]
Autism Diagnoistic Observation Schedule – Generic (ADOS-G) Lord, Risi,
Lambrecht, Cook Jr., Leventhal, DiLavore, Pickles & Rutter, 2000
Parent Interview for Autism (PIA) Stone & Hogan, 1993
Behavior Observation Scale (BOS) Freeman, Schroth, Ritvo, Guthrie &
Wake, 1980
The Autism Behavior Checklist (ABC) Krug, Arick, & Almond, 1980
The Vineland Adaptive Behavior Scales Sparrow, Balla, & Cicchetti,
1984
Wechsler Intelligence Scale for Children- III (WISC-III) Psychological
Corporation, 1997)
Wechsler Adult Intelligence Scale- III Psychological Corporation, 1991
Lord et al. (2000) reviewed the development of the Autism Diagnostic Observation Schedule – Generic (ADOS-G). The ADOS- G is a semi-structured assessment of social interaction, communication, play and imaginative use of material for individuals who may have autism or other PDDs. The authors describe the goal of the ADOS-G as to provide presses that elicit spontaneous behaviors in standardized contexts. The ADOS-G grew out of the ADOS, which was a method of standardizing direct observations of social behavior, communication and play in children suspected of having autism, and the PL-ADOS, which was a downward extension of the ADOS that could be used to assess nonverbal young children. It differs from the previous instruments in that it is aimed at providing standardized contexts for the observation of behaviors for a broader developmental and age range of individuals suspected of having autism. In this article, the authors describe the development, reliability and validity information and procedures involved in the administration of the ADOS-G. This instrument was found to be sensitive and specific for differentiating autism and PDDNOS from nonspectrum disorders. It provides moderate differentiation for autism from PDDNOS.
II. DEVELOPMENTAL PERSPECTIVE
Autism is considered a developmental disability
which changes over time and looks very different in infancy, childhood,
adolescence and adulthood. As a result, it is difficult not to consider
assessment and diagnosis from a developmental perspective. Using a developmentally
oriented, multi-axial approach is recommended as the behavioral features
and diagnosis criteria are best interpreted within a developmental context.
Continuous assessment from behavioral, educational, and medical points
of view are helpful because symptoms of autism vary according to age and
overall developmental level (Gillberg, 1989). Diagnostic reformulations
should continuously be made, as behavior can change dramatically over time,
and educational needs can vary from one period of time to another.
In addition, underlying medical conditions may not become manifest and
be “diagnosable” until the individual is older (often in puberty).
From a developmental perspective, it is important to focus on the disorder
within a conceptual framework of what is expected of children at particular
ages. For example, the most significant relationships in the lives
of infants and young children are caregivers, parents, and siblings. Therefore,
assessment should focus on obtaining information from these individuals.
In addition, behavioral observations of the child with autism and their
primary relationships should be obtained. As the child with autism becomes
an adolescent, peer relationships become more important; hence, assessment
should include examination of relationships with peers as well as parents
and siblings (Mesibov, Adams, & Klinger, 1997).
For the most part, assessment instruments
for autism are compatible with a developmental perspective. A thorough
evaluation of an individual with autism includes a comprehensive gathering
of information from numerous sources. By far, information from parents
is most often relied upon. Additional information is also obtained from
teachers and clinicians. However, there is a substantial lack of focus
on peer relationships of individuals with autism in the assessment process.
III. OPTIMAL ASSESSMENT STRATEGY
The optimal assessment strategy for autism
needs to be multidimensional, incorporating information from developmental
history, direct observation of behavior, interviews, and psychometric measures.
This is the most effective way of assessing autism because it accounts
for the inherent complexity of the disorder.
Volkmar (1998) provides the best description
of multidimensional assessment strategies for autism. The author describes
a thorough listing of assessment and diagnostic procedures for individuals
with autism. Historical information including early development, age and
nature of onset, and medical and family history should be obtained. A psychological
and communication assessment would focus on an estimate of the individual
with autism’s cognitive abilities, receptive and expressive language, language
skills, the use of nonverbal skills and pragmatic communication, and a
measure of adaptive behavior. A psychiatric evaluation would assess the
nature of social relatedness, (i.e., eye contact, attachment behaviors,
interest in peers, imitation skills, style of interacting), behavioral
features such as stereotypy or self-stimulatory behaviors, resistance to
change, unusual interests, unusual sensitivities to environmental conditions,
and play skills (i.e., use of play materials, developmental level of play
activities). Also important is a medical evaluation, including a genetic
screen, audiologic and visual testing, and neurological evaluation such
as EEG’s or MRI’s. Information should be obtained not only from behavioral
observation of the individual with autism, but also from caretakers,
other family members, teachers, and anyone involved in the individual’s
life on a regular basis.
The various components described by Volkmar
combine to form the most appropriate assessment strategy for autism; one
that is multidimensional and addressees the numerous contributing factors
in the development and maintenance of autism. Hopefully, more and more
professionals will begin to recognize the urgency of using such a multidimensional
assessment strategy so individuals with autism and their families are able
to receive the best possible care available.
IV. ASSESSMENT CONCLUSIONS
In conclusion, the assessment process for autism
is challenging and not always clear-cut because the disorder itself varies
greatly in its severity and symptomatology. As a result, diagnostic evaluation
for autism usually consists of some combination of information collected
from developmental history, direct observation of behavior, and psychometric
measures, including diagnostic instruments developed for autism. It is
important to obtain as much information as possible in order to provide
an accurate evaluation and diagnosis of the disorder, and to recommend
appropriate treatment. Recent and current retrospective research
indicates the potential to identify infants (>1) who are possibly at risk
for an autism spectrum disorder. As research continues to identify
early signs of potential autism, pediatricians can be trained to identify
at-risk children at an early age and appropriate treatment can be provided
an used in a preventative manner.
It is also important to frame autism from
a developmental framework and utilize the variety of assessments that exist
when assessing the disorder. An optimal assessment strategy includes a
developmental history, behavioral observation, a medical evaluation, and
additional information such as cognitive functioning and language ability.
As the characterizing features of autism can change within an individual
over time, it is important to continually assess the functioning and needs
of the individual. Frequent evaluation is helpful in identifying the educational
and treatment needs of the individual with autism.
I. TREATMENT
Autism has been increasingly viewed as a collection of disorders possibly with different etiologies but with similar manifestations. The frequently used term, “autism spectrum disorder” acknowledges the heterogeneity of the classification of autism. The variety of treatments available for autism also reflects the need to target specific autistic symptoms with specific interventions. Thus, the heterogeneity in phenotype of autism is reflected in the various treatment paradigms and approaches utilized for specific symptoms. Biological, educational, behavioral, and psychological approaches have all been applied in the treatment of autism, and all make claims about their effectiveness. While some report results that are encouraging, others have offered little evidence for efficacy. Many treatments a highly publisized in the media and on the web, but offer little empirical support. As a result, parents, educators, and other professionals need to be informed about what empirical studies report about the different treatment approaches. The following section will review the most recent findings about autism treatment and will include a section about optimal treatment.
Overview of Treatment
Prizant and Rubin (1999) claim that it is premature
and also misleading to claim that one treatment approach for autism is
more effective than others for the following reasons: 1) research provides
support for the effectiveness of a variety of approaches, which differ
in underlying philosophies and practice; 2) currently there exits no empirical
evidence supporting that one behavioral or developmental approach is more
effective; 3) no one approach is effective for all children; 4) available
research often contains methodological problems and shortcomings; 5) studies
have focused only on child variables and outcomes; 6) there exists no consensus
on “intensity of treatment”; 7) a great deal of overlap exists in approaches
having different philosophies and practice applications; 8) research has
failed to measure fidelity of treatment; and 9) research has not accounted
for variables outside the treatment package. Instead of arguing about which
treatment approach is more effective, the authors contend that several
tenets of practice should be addressed in all interventions for children
with autism, including: 1) treatment approaches need to be individualized
to a child’s needs and current developmental level; 2) intervention should
be based on current knowledge of child development; 3) intervention should
directly address the core components of Autism Spectrum Disorder; 4) treatment
approaches should be consistent in long term goals and teaching protocols;
and 5) treatment approaches should be based on a variety of sources.
Cohen (1999) also contends that no single
treatment approach is effective for all children with autism. The author
reviews the effectiveness of several approaches, including more traditional
applied behavior analysis interventions (such as the Lovaas Young Autism
Project), interventions based on more naturalistic approaches to applied
behavior analysis (such as Pivotal Response Training), and more developmental
approaches. The author states that each of the three approaches, when implemented
properly, helps some children with autism make significant gains
toward typical functioning. Nevertheless, none of the approaches helps
all children with autism achieve this optimal outcome. The author stresses
that what is needed is a database that enables professionals to identify
which children would do best with each particular treatment approach.
Campbell and colleagues (1996) present a review
of several treatments for autism and summarize the efficacy research for
these treatments. Conclusions are drawn regarding our current knowledge
of the effectiveness of treatments. Treatment approaches presented include
family approaches, educational approaches, behavioral/psychosocial approaches,
and biological approaches. The authors critique several specific treatment
models within each of these approaches such as Auditory Integration Training
and Fenfluramine.
Mesibov, Adams and Klinger (1997) discuss
several major approaches to the treatment of autism: psychodynamic, medical,
and educational/behavioral. The authors provide a brief overview of each
of the approaches, and discuss the concepts of “controversial treatments”,
versus “empirically supported” interventions. The authors attempt to provide
an objective review of several models of intervention as well as issues
such as early intervention, normalization, inclusion, punishment, and facilitated
communication.
Rogers (1998) describes the outcomes of comprehensive
treatment plans for children with autism. The criteria for empirically
supported treatments ( as described by C.J. Lonigan) were applied to 8
treatment efficacy studies. Although every case reported positive outcomes,
the author states that the field has yet to identify a treatment that meets
criteria for well-established or probably efficacious treatment. Various
hypothesized variables that the author proposes may affect outcome include
age of the individual at the start of treatment, type of treatment used,
the intensity of treatment, and the IQ and language levels at the start
of treatment. This article is useful for those interested in furthering
research in the area of treatment of autism, as well as parents or other
individuals interested in obtaining information about empirically supported
treatments.
Behavioral Approaches to Treatment
Koegel and Frea (1993) present a paradigm that
has emerged within the behaviorist orientation. Specifically, the authors
argue for the identification and targeting of pivotal behaviors that are
instrumental in producing change that generalized to many behaviors. Results
of their study indicate that interventions aimed at changing pivotal responses
result in changes in untreated behaviors as well. These findings are based
on the responses of two high-functioning children with autism. The authors
provide an explanation for the effectiveness of pivotal response training
based on a functional analysis of behaviors.
Koegel and colleagues (1999) present an overview
of their pivotal response interventions. The authors discuss that their
research efforts at the University of California, Santa Barbara have been
centered around identifying pivotal areas of behavior, that when changed
result in collateral positive changes in other behaviors. The article discusses
several pivotal areas of behavior, including responsivity to multiple cues,
self-regulation of behavior including self-initiations an self-management,
and motivation to initiate and respond appropriately to environmental stimuli.
The authors also present the variables involved in teaching motivation,
which include following child choice, using natural reinforcers, interspersing
maintenance trials in acquisition trials, and reinforcing attempts.
Koegel and colleagues (1999) discuss preliminary
long-term outcome data for their pivotal response interventions. Specifically,
the authors divided their study into two separate phases. Phase 1 involved
looking at archival data of children who either had favorable or unfavorable
intervention outcomes and assessing “whether the presences of spontaneous
self-initiations” was associated with the more favorable outcomes. Phase
2 involved assessing whether children who lacked spontaneous self-initiations
could be taught initiations as a pivotal behavior, and if these children
would experience favorable outcomes. The results for Phase 1 indicate that
the children who had the more favorable intervention outcomes displayed
more spontaneous self-initiations before intervention. The results for
Phase 2 indicate that children who initially lack spontaneous self-initiations
could learn a variety of self-initiations and that these children experienced
favorable outcomes. In conclusion, the authors discuss the importance
of their preliminary outcome data as it relates to assessing key pivotal
behaviors which might be identified as prognostic indicators and be critical
in the treatment of children with autism.
Gresham and MacMillan (1998) discuss the claims
made by the Early Intervention Project (EIP; Lovaas 1987, 1993; McEachin,
Smith & Lovaas, 1993) of recovery in 47% of their cases of autism,
and reduced severity in 42% of their cases. The article evaluates the EIP
study in terms of internal and external validity, as well as from a methodological
standpoint. The authors recommend that the results of the Early Intervention
Project be carefully evaluated in respect to these critiques.
The chapter by Harris (1998) provides a review
of the “state of the art” in behavioral and educational treatments for
individuals with PDD’s. The behavioral technology for early intervention
for children with PDD, including autism is discussed and evaluated, as
well as controversial treatment approaches such as facilitated communication,
and auditory integration therapy. The need to consider family context when
choosing a treatment approach is addressed.
In addition, Harris & Weiss (1998) discuss
intensive behavioral intervention (IBI) for young children (primarily age
5 and younger) who fall within the spectrum of Pervasive Developmental
Disorder. The authors describe how Applied Behavior Analysis (ABA) can
be used to teach speech, language, social, motor, and adaptive skills.
Also discussed is what families should consider before choosing any treatment
method for their child with autism. Curriculum, professional roles, parent
involvement, inclusion, and the “pros and cons” of a home-based vs. a center-based
program are described. A “real-life” family’s account provides personal
experience of receiving a diagnosis for their child and the process of
choosing a treatment program.
Miranda-Linn and Melin (1992) compare the
effectiveness of incidental and discrete trial techniques as methods for
increasing language skills. The techniques were compared in terms of the
speed of acquisition, retention of behaviors, and efficiency. No differences
were reported for retention of learned behaviors, however, discrete trial
methods resulted in faster learning and also took less time. More importantly,
the authors suggest that effectiveness of techniques may depend upon the
nature of the targeted behavior. Specifically, discrete trial methods may
be more effective for teaching language forms, while incidental teaching
may increase spontaneous language use. Thus, application may vary across
developmental levels.
Schreibman (1996) summarizes the progress
made in behavioral research in the past three decades to illustrate the
importance of the behavioral approach to the treatment of autism. She argues
that the research in behavioral methods of treatment has led to the development
of empirically validated treatments ameliorating much of the symtomatology
of autism. In addition, she suggests that the behavioral approach is essential
for addressing the specific and varied symptoms of autistic disorder.
Educational Approaches to Treatment
Schwartz and colleagues (1998) present the
case studies and outcomes of three children with autism who received school-based
educational services during their preschool and kindergarten years. All
three students had positive outcomes and made significant academic and
developmental gains. In addition, all three students entered inclusive
elementary school programs and continued to make progress. According to
the authors, the purpose of reporting these findings is to demonstrate
that there exist several ways to achieve positive outcomes for children
with autism.
Berkell and Malgeri (1996) provide a review
of research investigating the efficacy of Auditory Integration Training
(AIT) in the treatment of autism. The authors explain succinctly the theory
and methods of this technique and identify controversies pertaining to
the use of AIT by untrained professionals and difficulties with technology.
They conclude that methodological shortcomings of empirical studies with
this technique preclude the generalizability of findings. Thus, there has
been no systematic validation of AIT.
Mumford et al. (2000) found similar results
in their experimental study of Auditory Integration Trainig (AIT).
In their study, a crossover experimental design was used to compare AIT
to contol treatmrent for 16 children with autism. Parent rated measures
of hyperactivity showed that the control condition was superior.
No differences were found on teacher-rated measures. A majority of
the parents were not able to report in retrospect when their child had
received auditory intergration training. The authors concluded that
no individual children were identified as benefiting clinically or educationally
from the treatment.
Fine and Fine (1999) explain the difficulties
associated with treating autism with psychotherapy. Using both a theoretical
and clinical approach, the contribution of psychoanalysis is discussed.
Various theoretical frameworks to view the etiology and treatment of autism
are also discussed.
Howlin (1998) discusses the underlying causes
of behavioral disturbances and the role that social communication and obsessional
difficulties play in causing and maintaining them. She reports that there
is not a single mode of treatment likely to be effective for all children
and all families. She concludes that the role of professionals is to provide
families the information and support they need, in order to enable them
to identify problems at an early stage, and to help them develop management
strategies that will minimize the impact of the child’s social, communicative,
and obsessional difficulties later in life.
Light and colleagues (1998) discuss the use
of augmentative and alternative communication (AAC) in enhancing comprehension
and expression of individuals with autism. A model of AAC assessment and
intervention planning is presented, and application of the model is described
through the case report of a 6-year-old boy with autism who had severe
receptive and expressive language impairments.
Siegel and Zimnitzky (1998) review and critique
existing research on two techniques used in the treatment of children
with autism, namely facilitated communication and auditory integration
training. The authors discuss the popularity of the techniques, yet the
authors find little support for the efficacy of AIT for individuals with
autism. In addition, the authors discuss that since 1993, research has
tended to invalidate various assumptions underlying FC.
Simpson and Smith (1995) also address the
controversy surrounding Facilitated Communication as a paradigm for the
treatment of autism. Results of a study of 18 children with autism replicated
the results of previous studies that found Facilitated Communication techniques
to be unsuccessful in producing behavioral change.
Biological Approaches to Treatment
Harteveld and Buitelar (1997) provide and overview
of the diagnostic and therapeutic approaches to children, adolescents,
and adults with autism and other pervasive developmental disorders. Comprehensive
assessment is discussed, including a developmental history, interview with
parents, behavioral observation, psychological testing, and medical examination.
The authors state that the treatment should be multimodal, involving a
combination of structured and special education techniques, individual
skills training, behavioral modification, home treatment, and vocational
schools or day care centers. The role of drug treatment is discussed in
treatment of maladaptive target symptoms such as hyperactivity, aggression,
excitement, negativism, and ritualized stereotypes, or self-injurious behaviors.
Medications mentioned to be considered are antipsychotics, selective serotonin
reuptake inhibitors, other serotonergic drugs, opiod receptor antagonists,
stimulants, clonidine, propanolol, lithium, and anticonvulsants.
McDougle (1998) presents a chapter review
of psychopharmacology research in pervasive developmental disorders (PDD’S)
from the perspective of specific neurochemical systems. Research on the
effects of drugs affecting serotonin function (fenfluramine, buspirone,
clomipramine, fluvoxamine, fluoxetine, and sertraline), drugs affecting
dopamine function (haloperidol, pimozide, and stimulants), drugs affecting
norepinephrine function (beta blockers, clonidine), and drugs affecting
neuropeptide function (naltrexone and adrenocorticotrophic hormone (ACTH)
analogue) is provided and discussed in relation to PDD’s, including autism.
The gastrointestinal hormone, secretin,
has recently received considerable attention in the media as a possible
treatment for autism. This stemmed from one study that reported that
secretin had significant effects in reducing behavioral symptoms of autism
in three children. A recent study by Chez et al. (2000) investigated the
claims of the original secretin study. This study found that, although
treatment with secretin was reported to have caused transient changes in
speech and behavior in a few children, overall it produced few clinically
significant changes compared to those who received saline, placebo, injections.
Pfeiffer and colleagues (1995) offer a thorough
search for empirical studies examining the effectiveness of vitamin B6
and magnesium megadoses in the treatment of autism. The authors provide
a rigorous critique of 12 papers identifying strengths and weaknesses of
studies. They conclude that while the results indicate that vitamin B6-Mg
megadoses do have an effect on neurotransmitter metabolism, the methodological
flaws inherent in the design of the studies reviewed limit the interpretation
of the findings.
Rimland (1998) argues that the article
written by Pfeiffer and colleagues (1995) about the effectiveness
of vitamin B6 and magnesium megadoses in the treatment of autism contained
many problems, including misconceptions, omissions, and errors. Rimland’s
criticisms include the fact that Pfeiffer and colleagues only included
12 of the 18 studies published about the effectiveness of vitamin B6 and
magnesium treatments for autism. Rimland does not appear to be opposed
to criticism of studies examining vitamin B6 and magnesium effectiveness
in treating autism, but specifies that criticisms cannot be naive and based
on errors, omissions or misconceptions.
II. DEVELOPMENTAL PERSPECTIVE
In order to account for the heterogeneity of
autism characteristics, treatment must be flexible both in its ability
to deal with individual differences, and in the intensity of various
behaviors. In addition, treatment approaches must take into account both
the effect of developmental deficits on further development and the appearance
of different symptoms at different ages. Behavioral studies suggest that
early intervention is an important factor in determining the effectiveness
of interventions with children with autism. This may be interpreted as
indicating a critical period for intervention due to increased plasticity
in the early years (Rogers, 1996). In addition, as suggested above, early
deficits in perception and integration of information may result in the
social and language difficulties of autism. The inability to negotiate
social situations may in turn lead to active avoidance behavior. Thus,
many cases symptoms of autism may be viewed as caused by underlying developmental
deficits such as restricted ability to perceive social cues which lead
to a failure to develop age appropriate skills in diffuse areas. Treatment
aimed at facilitating progress in specific developmental arenas must take
into account the processes that precede the symptom development.
In addition, knowledge of normal development
must guide the use of interventions as behavior targets differ at each
level of development. Treatment aimed at eliminating negative behaviors
in children with autism must address the different symptoms that manifest
across age groups. As children with autism develop, their symptoms also
may change. For example, younger children with autism often exhibit irritability
and hyperactivity. In adolescent years, depression and obsessive compulsive
behaviors may be common. The implication of this developmental perspective
is the use of different treatment approaches and interventions for different
stages of development.
III. OPTIMAL TREATMENT
Several treatment approaches have been discussed
in this section, including educational, biological, and behavioral treatment
approaches. Of the treatment approaches discussed, the one that has been
most consistently validated across different subtypes of autism is the
behavioral approach. In addition, the importance of early intervention
has been stressed in much of the literature since age at intake has been
shown to be a reliable predictor of progress (Harris & Handleman, 2000).
Therefore, an optimal treatment approach for autism needs to involve
early behavioral intervention.
Other approaches, such as pharmacological
interventions or the use of Auditory Integration Training, have provided
some evidence for effectiveness in reducing specific target symptoms of
autism. However, behavioral techniques have shown flexibility in
reducing a diffuse array of symptoms and bringing about widespread changes.
In addition, the use of behavioral techniques allows for a sensitivity
to developmental considerations that is essential in the treatment of autism
since different symptoms may be present at different developmental stages.
Many different theories guide the use of behavioral
interventions for children with autism. While some argue for intensive
training addressing all behavioral deficits exhibited, others have suggested
targeting pivotal behaviors, such as motivation, which may yield collateral
changes in a broad range of behaviors. In addition, some have argued for
the effectiveness of incidental teaching over that of discrete trial training.
Research in behavior modification is continuing to increase the effectiveness
and efficiency of behavioral interventions in producing lasting improvements
in the symptomatology of autism. While it is unclear which theory of behavioral
intervention will prove most useful in treating children with autism, the
application of behavioral techniques has already improved the standard
of living for people with autism. In reviewing the different approaches
to behavioral interventions, educators should keep in mind the heterogeneity
inherent in the disorder, and tailor interventions accordingly. In addition,
educators and other professionals should employ developmental considerations
as a guide for the use of particular paradigms in addressing the different
symptomatology exhibited across age groups.
IV. TREATMENT CONCLUSIONS
Reviewing efficacy studies highlights the importance of recognizing different subtypes of autism. From this perspective, no one approach should be applied across all individuals. Therefore, educators need to tailor treatment according to the individual’s specific needs and take into consideration the individual’s prior development, symptoms, and family needs. As a result of these considerations, treatment should be based on an analysis of what will work most effectively with the individual and those in his or her environment.
V. CONCLUSION
Science has made great strides in the
last three decades in increasing our overall understanding of the epidemiology,
etiology, assessment and treatment of autism. We now recognize that there
exists no single cause of autism, but consider autism as developing from
an interplay of genetics, neurobiological, and neuroanatomical components.
Optimal assessment strategies for autism also involve multidimensional
components, incorporating information from developmental history, direct
observation of behavior, interviews and psychometric measures. In
addition, the study of autism has moved toward a view of autism as a collection
of different disorders with different etiologies. Implied in this perspective
is the need for treatments to reflect this heterogeneity. Behavioral
interventions provide the most optimal treatment for children with autism
by being able to address the disorder’s inherent heterogeneity and produce
wide spread changes.
Many new and highly publicized
treatments may arise and make claims about their efficacy. Despite
the appeal of new treatments, it is important to critically evaluate
the empirical base behind such claims, as they may be misleading or lack
the strong research base needed to determine a treatment effective.
Despite the fantastic strides science has made in improving our understanding
of autism and improving the quality of life for individuals with autism,
there is still much work to be done. Perhaps an integration of research
in different disciplines will lead to a more comprehensive and accurate
understanding of autism. In the meantime, professionals must employ the
information empirical studies provide and implement the best possible interventions
for each individual with autism.
VI. WORLD WIDE WEB SITES
General Autism Information
http://www.autism-society.org/autism.html
The Autism Society of America’s webpage gives an overview of
the general characteristics and diagnosis of autism and subtypes of autism
spectrum disorders. The page also briefly discusses possible causes
of autism and explains outdated ones. Of particular interest is the
description of typical individuals with autism. This description
clearly addresses the variability and heterogeneity in autism symptomatology
and dismisses common myths. The page briefly summarized treatments
of autism. This page is useful to get a general information about etiology,
epidemiology, assessment and treatment of children with autism spectrum
disorders.
Autism- Overview
http://www.autism.org/overview.html
This site, presented by Stephen M.Edelson, Ph.D. of the Center
for the Study of Autism in Salem, Oregon provides a fairly thorough overview
of autism. In addition to a description of autistic disorder, it also provides
information regarding prevalence, subgroups and related disorders, etiology,
sensory impairments, cognition, and interventions. This site discusses
a variety of viewpoints and theories, and is written in a clear and concise
manner. It provides a good amount of basic information, and is easy to
read and understand.
Laboratory Research on the Neuroscience of Autism
http://nodulus.extern.ucsd.edu/
This site provides information on the current and past research
on the neuroscience of autism. It gives a timeline of the related
findings. This site is useful in keeping abreast of up-to-date research
in this area. The site also gives a description of current projects
of the laboratory and links to other resources.
Resources for School Psychologists
http://www.sasked.gov.sk.ca/curr_inst/speced/hero.html
This site is a general description of autism and detailed
educational strategies that may be helpful for school psychologists working
with a child with autism. Strategies covered include, behavioral
assessment, behavior interventions, structuring the learning environment,
social skills training and many other specific suggestions on educating
a child with autism. This site is useful because it presents a great
deal of information in a succinct and organized manner. Additionally, the
strategies presented are specific and detailed enough to be useful.
Assessment
http://psy-svr1.bsd.uchicago.edu/ddc/home.htm
This is the website for the Developmental Disorders Clinic at
the University of Chicago. This website is useful in order to view
current research in the areas of assessment, molecular genetics and pharmacological
treatments. Additionally, information is available on upcoming trainings
in the use of diagnostic instruments used in assessing children with autism
(ADI-R and ADOS).
Assessment Information for Parents
http://www.behavior-consultant.com/assessme.htm
This site, which is also provide for by Clinical and Behavioral
Consultants of R+einforcement Unlimited, is geared more for parents of
children with autism, rather than professionals providing assessment. The
distinction between traditional psychometric assessment, and functional
assessment, particularly functional behavioral assessment as specified
by IDEA is discussed. While the site is a description of the services that
the consultants provide, the information is helpful for parents or other
who are not familiar with different types of assessments.
Autism Symptoms Checklist
http://www. autism-society.org
This site provides a checklist of some of the most common symptoms
of autism which is very easy to understand. The symptom list, which provides
both a pictorial depiction and a written description of the symptom, is
not intended to be a substitute for a professional diagnostic assessment,
but is intended to provide parents, educators, and other professionals
who are not very familiar with autism with a quick and clear introduction
to autism symptomatology. A total of 18 symptoms are provided, and include
the following: little or no eye contact, echolalia, insistence on sameness,
resistance to change, sustained odd play, and lack of responsivity to verbal
cues. This is a good site for individuals who know little about autism
to start because it does not overwhelm the reader with technical jargon
or too much information. The site does also suggest that parents contact
a health care provider for a complete assessment.
Theory of Mind
http://www.feat.org/autism/HarvardAutism.htm
This page is part of a more comprehensive website presented
by Families for Early Autism Treatment (FEAT). This site focuses on research
into the nature of autism, taken from the Harvard Mental Health Letter
(1997). It discusses theories such as individuals with autism having a
higher level of arousal, that pathology is mainly perceptual, as well as
the highly controversial “Theory of Mind” hypothesis. This theory states
that the disorder is primarily cognitive, the result of an inability to
think in certain ways. According to one view, individuals with autism are
unable to share experience and express emotion in a normal manner because
they cannot anticipate the thoughts and actions of others, nor can they
understand that others have their own intentions, emotions, and perspectives.
The site is not particularly concise, but free from technical jargon. This
site is an interesting read as it discusses various theories, including
one that has been subjected to much criticism. References for additional
readings are also listed.
Autism Research Center at UC Santa Barbara
http://www.education.ucsb.edu/~autism/
A description of the overall orientation of the Autism Research Center
at University of California, Santa Barbara is provided. The web page lists
several resources for parents and practitioners interested in Pivotal Response
Training. This paradigm maximizes the effectiveness of behavioral techniques
by targeting the individual’s strengths and pivotal behaviors such as motivation.
Updated journal information on the Journal of Positive Behavioral Interventions
is provided. Upcoming dates and locations of presentations by Drs.
Robert and Lynn Kern Koegel and their graduate students are listed.
Treatment and Education of Autistic
and Related Communication Handicapped Children
http://www.unc.edu/depts/teacch
Division TEACCH, a comprehensive program providing services to autistic
individuals and their families presents a website with various related
topic. The site provides an overview of the program (a brief overview of
division TEACCH, TEACCH services), detailed descriptions of their behaviorally-oriented
treatment paradigm (TEACCH services), and concrete suggestions for parents
and teachers for ways in which to provide optimum teaching environments
for children with autism (Structured Teaching, Structuring for Success,
Nonverbal Thinking, Communication, Imitation, and Play Skills from a Developmental
Perspective). In addition, a review of current treatment approaches is
presented (A Pediatric View of Treatment Options for Autistic Syndrome)
and guidelines for evaluating treatment programs (Evaluation Guidelines
When Considering Nontraditional Therapies in Autism). This site is useful
in providing general information regarding the treatment of autism. It
also describes in detail several behavioral methods used by teachers and
practitioners with children with autism. Division TEACCH has a strong research
component which supports their use of behavioral and educational methods.
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