DIAGNOSIS AND CLASSIFICATION IN AUTISM

This study compared four systems for the diagnosis of autism (DSM-III; DSM-III-R, DSM-IV and ICD-10) with two empirically derived taxa of au tism, and with three social subgroups of autism (Aloof; Passive, and A ctive-but-Odd) in 194 preschool children with salient social impairmen t. There were significant behavior and IQ differences between autistic and other-PDD groups for all four diagnostic systems, and a significa nt association was found (a) for Taxon B, diagnoses of autism, and the Aloof subgroup, and (b) for Taxon A, other-PDD, and the Active-bur-Od d subgroup. Findings offer support for two major overlapping continua within idiopathic Pervasive Developmental Disorder.