SUBTYPES OF AUTISM BY CLUSTER-ANALYSIS

Multidisciplinary data from 166 children with autistic spectrum disord ers were subjected to cluster analysis. Cross-validation between rando m halves of the sample showed acceptable consistency of the clustering method. Four clinically meaningful subtypes emerged from the analysis . They did not differ in demographic characteristics but did show, on average, distinct differences in behavioral and cognitive areas. Over half of the sample fell into a subtype described as typically autistic with abnormal verbal and nonverbal communication, aloofness, impaired social skills, and sensory disturbances. Another 19% were similarly a utistic but with moderate to severe mental handicap. The remaining chi ldren formed two subtypes: a high-functioning Asperger-like group who were overactive and aggressive, and a small group who were impaired in social and language skills, had restricted interests, and a family hi story of learning problems. This study highlights' important differenc es among children with autism and emphasizes relationships between cog nitive functioning and subtypes of the disorder.