Abstract

Eighteen preschool children diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders Third Edition Revised (DSM III-R) as having Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) were compared to 176 children with DSM III-R Autistic Disorder (AD), and to 311 non-autistic children with developmental language disorders (DLD) (N = 201) or low IQ (N = 110). All children were partitioned into "high" and "low" cognitive subgroups at a nonverbal IQ of 80. Within cognitive subgroups, the 18 PDD-NOS children did not differ significantly from either the DLD or the AD children in verbal and adaptive skills and obtained scores intermediate between those of these groups. The PDD-NOS did not differ from the AD children in maladaptive behaviors. Both the PDD-NOS and AD children had many more of these behaviors than the non-autistic comparison groups. Children in the "high" and "low" cognitive subgroups of AD, but not of PDD-NOS, differed substantially on most measures, with the children with lower cognitive scores significantly more impaired on all measures. Similarity of PDD-NOS children to AD children in maladaptive behaviors and an intermediate position between autistic and non-autistic groups on virtually all measures explains the difficulty clinicians encounter in classifying children with PDD and raises questions about the specificity of these diagnostic subtypes of the autistic spectrum.

View details for Web of Science ID 000167825700009

View details for PubMedID 11315538