Emerging adult outcomes of adolescent psychiatric and substance use disorders.

This study investigates the age 25 outcomes of late adolescent mental health and substance use disorders. A hierarchical cluster analysis of age 19 DSM-III-R mental health and substance diagnoses placed participants into one of 9 clusters: Anxious, Depressed, Antisocial, Drug Abuser, Problem Drinker, Anxious Drinker, Depressed Drug Abuser and Antisocial Drinker, and No Diagnosis. Diagnoses were generated from the University of Michigan Composite International Diagnostic Interview. Repeated measures multivariate analyses of variance revealed distinct trajectories of improvement and decline among the 9 clusters. Clusters with co-occurring substance and mental health disorders improved over adolescent levels, but continued to have higher levels of depression symptoms, poorer global functioning, and higher levels of substance use than the No Diagnosis cluster. Members of the The Problem Drinkers cluster, who tended to have alcohol use disorders only at age 19, did not differ from their peers with no diagnoses. Drug use disorders in adolescence, with or without a co-occurring mental health disorders, were associated with a poor prognosis in emerging adulthood. Clinical interventions should distinguish among these diverse clinical presentations.