Journal of Autism and Developmental Disorders, Vol. 31, No. 1, 2001
Editorial Preface
This issue of the Journal of Autism and Develop-
mental Disorders includes a number of articles related
to high-functioning individuals with autism or Asperger
disorder. The rapid increase in the identification of these
individuals over the past 5 years makes this subgroup a
particularly timely focus. The recently published 6-year
follow-up study of the Checklist for Autism in Toddlers
reported 57/10,000 children with Autism, Asperger dis-
order, Atypical Autism, and Pervasive Developmental
Disorder Not Otherwise Specified, of which 70% were
nonmentally retarded (Baird et al., 2000). The bound-
aries between high-functioning autism and Asperger dis-
order, on the one hand, and the broader autism pheno-
type and impaired skills on the other is difficult to
define. DSM-IV-R has attempted to address this issue
by emphasizing the almost incapacitating impact of the
impairments on life function as the dividing line be-
tween individuals with Pervasive Developmental Dis-
order and individuals with traits or skill difficulties that
are qualitatively similar.
Two articles in this issue are related to diagnosis.
Baron-Cohen and colleagues report the development of
a new self-administered instrument, the Autism-Spectrum
Quotient, for measuring the degree to which adults of
normal intelligence have the traits associated with
autism. This 50-question interview is not diagnostic, as
a high score is not automatically indicative of a clini-
cal diagnosis of autism or Asperger disorder. That is,
all high-scoring individuals did not qualify for a diag-
nosis of Asperger disorder or high-functioning autism;
again a distinction was drawn between those who were
able to function successfully in society and those who
were not. This instrument provides a potential method
for comparing where individuals fall on the spectrum
of autism traits relative to each other and possibly also
for screening to identify individuals in need of further
evaluation for Asperger disorder and high-functioning
autism. A second article addresses the question of di-
agnostic overlap between high-functioning autism and
schizophrenia. A key distinction is between overlap of
some symptoms and overlap in diagnosis. Clinical sim-
ilarities are not surprising given that the term “autism”
originally referred to the social isolation, affective flat-
tening, and apathy seen in individuals with schizo-
phrenia. The present study, like an earlier study com-
paring autism and schizophrenia (Rumsey, Andreasen,
& Rapoport, 1986), found an overlap primarily in neg-
ative symptoms (reduced facial affect, reduced social
contact, apathy, alogia, and problems with attention)
but not in positive symptoms (hallucinations, delusions,
bizarre behavior, and formal positive thought disorder).
Although half of the individuals with autism met cri-
teria for Disorganized schizophrenia subtype based on
negative symptoms ALONE, they did not have all the
features of schizophrenia; a critical difference was the
absence in the individuals with autism of delusions and
hallucinations, two cardinal symptoms of schizophre-
nia. The central question for parents and clinicians is
whether children with autism will develop schizophre-
nia in later life. This was addressed by Volkmar and
Cohen (1991) who found that the rate of schizophrenia
in autism was 0.6%, not higher than the general popu-
lation and is supported by the absence of delusions and
hallucinations in the high-functioning individuals with
autism in the present study. Had the full syndrome of
schizophrenia been required for a diagnosis of schizo-
phrenia in the present study, then none of the individ-
uals with autism would have met criteria for schizo-
phrenia. The second question is whether individuals
with autism should be considered as being comorbid
for schizophrenia based on the overlap in negative
symptoms. I would say not. Some symptoms are com-
mon to both disorders and a diagnosis of autism is suf-
ficient to account for the “negative symptoms”; invok-
ing a comorbid condition entails counting the symptoms
twice (once for autism and once for schizophrenia). An
alternative explanation for the overlap in symptoms is
that autism and schizophrenia involve many of the same
brain systems; the differences in symptoms may reflect
the very different stages in brain development when the
disorders begin and basic differences in the nature of
the biologic process. The clinical similarities between
high-functioning autism and schizophrenia highlight
the potential for misdiagnosis of high-functioning in-
dividuals with autism as having schizophrenia. Al-
though neuroleptics may be helpful in both disorders
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0162-3257/01/0200-0001$19.50/0 © 2001 Plenum Publishing Corporation