Psychiatric and substance use disorders in South Florida: racial/ethnic and gender contrasts in a young adult cohort.

BACKGROUND: Prevalence rates of psychiatric and substance use disorders among young adults in South Florida are presented. Unique aspects of the study include the large sample size, its ethnic diversity, and the fact that a substantial proportion of Hispanic participants were foreign born. METHODS: This study builds on a previous cohort study of students who entered middle school in 1990. A random subsample of this representative cohort (N = 1803) was interviewed between 1998 and 2000 when most were between 19 and 21 years of age. Disorders were assessed through computer-assisted personal interviews utilizing the DSM-IV version of the Michigan Composite International Diagnostic Interview. RESULTS: More than 60% of the sample met lifetime criteria for 1 or more study disorders, and 38% did so within the preceding year. Childhood conduct and major depressive and alcohol abuse disorders were the most prevalent. Although rates of affective and anxiety disorders in females were double that in males, this gender difference disappeared when attention-deficit/hyperactivity disorder, conduct disorders, and antisocial personality disorders were also considered (46.6% vs 45.7% for females vs males, respectively). Substantially lower rates were observed among African Americans for depressive disorders and substance abuse and dependence. Among Hispanics, rates tend to be lower among the foreign-born in comparison with their US-born counterparts, particularly for the substance disorders. CONCLUSIONS: The documented presence of psychiatric and substance disorders in middle and high school populations emphasizes the importance of prevention efforts in school settings. Research on the origins of ethnic and nativity differences is called for.