The research sample consisted of 147 adolescents and 112 children being treated for psychiatric problems at an Ohio Psychiatric Hospital from September 1983 to June 1985 and 3,280 juvenile delinquent/unruly cases referred to the juvenile court in the area during 1984. Records of these juvenile offenders, whose ages ranged from 7 to 21 years old, were double checked to determine extrafamilial adoption (EFA) -- legal adoption by nonrelatives, and intrafamilial (IFA) -- legal adoption by stepfathers or relatives. The general population rate was estimated by a survey of literature and community agencies. Identification of adoptees in the psychiatric group was achieved by record review and by interviewing clinicians who worked with all the subjects. Findings revealed a significantly lower rate of IFA in both psychiatric inpatient and juvenile court subjects than in the general population. When compared with the EFA adoption rate of the general population in the region, the study found a significant overrepresentation of adopted children and adolescents among inpatient psychiatric subjects, and a significant underrepresentation of adopted children and adolescents referred to juvenile court. 34 references.