, Volume 22, Issue 4, pp 583-600

The validity of autistic spectrum disorders: A literature review

Abstract

The objective of this literature review is to assess the validity of autistic spectrum disorders (ASD). Twenty papers were identified that adequately investigated the internal or external validity of various subtypes of ASD. At least three groups can be distinguished from autism on clinical grounds; an Asperger syndrome subtype, and two atypical subtypes characterized by low IQ and high IQ. However, the evidence that these clinical distinctions carry inferences with respect to etiology, clinical course, and treatment is only suggestive. Nevertheless, the specification of several ASD subtypes might promote further research and resolve many of the nosologic issues with respect to the classification of pervasive developmental disorders (PDDs).

The literature review was prepared for the APA DSM-IV Advisory Group on Pervasive Developmental Disorders. The opinions expressed in the paper are solely those of the author, and not those of the APA or the Advisory Group. The author thanks members of the committee for their helpful comments and the reviewers who commented on an earlier version of this paper. The author was supported in the preparation of this paper by grants from the Ontario Mental Health Foundation and National Health and Welfare, Canada.