Characteristics of community-based individuals with mental retardation and aggressive behavioral disorders.

A cohort of 199 individuals with mental retardation referred for behavioral and psychiatric crisis intervention services was studied to determine attributes differentiating physically aggressive behavior from other behavioral problems. Individuals with aggressive and nonaggressive behavior had similar neurological histories and current medical status and similar levels of seizure disorders and CNS abnormalities. Aggressive individuals more often had psychiatric diagnoses of organic brain syndrome, but frequencies of this diagnosis in each group were small. Current aggression was predicted by gender, level of mental retardation, and history of previous institutional placement; the strongest predictor was history of aggression. These data suggest a complex equation to describe social inadequacy involving interactions between CNS functioning and developmental cognitive and social variables that are only partially defined at this time. Further work to characterize this interaction almost certainly must include a prospective longitudinal analysis of social and developmental functions early in life.