Cluster analytic identification of autistic preschoolers.

Cluster analysis was performed on factor analytic symptom profiles obtained from the Achenbach CBCL for a clinical sample of 204 3- to 5-year-old boys containing 79 autistic and autistic-like children. Patterns of results across 2-, 3-, 4-, 5-, and 6-cluster solutions are presented. Clustering identified an autistic group as soon as three clusters were formed. As more clusters were obtained, this autistic cluster was subdivided according to presence/absence of anxiety and level of functioning. Other clusters included an emotional/behavioral disorder group, with some differentiation into Externalizing and Internalizing clusters, and a group of relatively normal children with few symptoms.