The development of a new standardized investigator-based interview for use in the differential diagnosis of pervasive developmental disorders is described, together with a diagnostic algorithm based on its use. The algorithm correctly identified 16 autistic individuals and none of the 16 nonautistic mentally handicapped subjects. (Author/DB)

This paper reviews whether Rett syndrome is a subtype of pervasive developmental disorders (PDD). The paper analyzes internal and external diagnostic validity and discusses whether Rett syndrome is a neurological disorder or a mental disorder. The paper concludes that data support the idea of classifying Rett syndrome as a subtype of PDD.…

This paper provides a history of the development of the DSM-III-R (Diagnostic and Statistical Manual III, Revised) section on pervasive developmental disorders. It describes the process by which the text and criteria for "Autistic Disorder" and "Pervasive Developmental Disorder Not Otherwise Specified" were decided and gives…

This essay notes the complexities inherent in classifying pervasive developmental disorders (PDD), especially when a single classification scheme is to be used for clinical, research, and administrative purposes. The paper considers principles of classification, symptomatology, the neuropsychiatric interface, the value of a multiaxial approach,…