Childhood and Adolescent Psychiatric Disorders as Predictors of Young Adult Disorders

Context: Most adults with a psychiatric disorder first met diagnostic criteria during childhood and/or adolescence, yet specific homotypic and heterotypic patterns of prediction have not been firmly established. Objective: To establish which childhood and adolescent psychiatric disorders predict particular young adult disorders when accounting for comorbidities, disaggregating similar disorders, and examining childhood and adolescent predictors separately. Design: Eleven waves of data from the prospective population-based Great Smoky Mountains Study (N=1420) were used. Setting: The Great Smoky Mountains Study is a longitudinal study of the development of psychiatric disorder and need for mental health services in rural and urban youth. A representative sample of children was recruited from 11 counties in western North Carolina. Participants: Children in the community aged 9 to 16, 19, and 21 years. Main Outcome Measures: Common psychiatric disorders were assessed in childhood (ages 9-12 years) and adolescence (ages 13-16 years) with the Child and Adolescent Psychiatric Assessment and in young adulthood (ages 19 and 21 years) with the Young Adult Psychiatric Assessment. Results: Adolescent depression significantly predicted young adult depression in the bivariate analysis, but this effect was entirely accounted for by comorbidity of adolescent depression with adolescent oppositional defiant disorder, anxiety, and substance disorders in adjusted analyses. Generalized anxiety and depression cross-predicted each other, and oppositional defiant disorder (but not conduct disorder) predicted later anxiety disorders and depression. Evidence of homotypic prediction was supported for substance use disorders, antisocial personality disorder (from conduct disorder), and anxiety disorders, although this effect was primarily accounted for by DSM-III-R overanxious disorder. Conclusions: Stringent tests of homotypic and heterotypic prediction patterns suggest a more developmentally and diagnostically nuanced picture in comparison with the previous literature. The putative link between adolescent and young adult depression was not supported. Oppositional defiant disorder was singular in being part of the developmental history of a wide range of young adult disorders.