Familial aggregation of adolescent personality disorders.

Objective: A family study of DSM-III-R personality disorders was conducted in the families of 66 clinically referred adolescents to examine the validity of personality disorder diagnoses in adolescents.
Method: Semistructured interviews of Axis I and II disorders, including the Structured Clinical Interview for DSM-III-R Personality Disorders, were used to directly interview 66 clinically referred adolescents and their adult first-degree family members, combining family study and family history data.
Results: The relatives of adolescents with avoidant personality disorder had an increased prevalence of avoidant and cluster A (schizoid, schizotypal, and paranoid) personality disorders. The relatives of adolescents with borderline personality disorder demonstrated increased rates of borderline and avoidant personality disorders, even after adjusting for comorbidity.
Conclusions: The results of this study support the validity of Axis II diagnoses, particularly avoidant and borderline disorders, in adolescents.