A family study of major depressive disorder in a community sample of adolescents

Background: Family studies provide a useful approach to exploring the continuities and discontinuities between major depressive disorder (MDD) in children and adolescents and MDD in adults. We report a family study of MDD in a large community sample of adolescents. Methods: Probands included 268 adolescents with a history of MDD, 110 adolescents with a history of non-mood disorders but no history of MDD through age 18 years, and 291 adolescents with no history of psychopathology through age 18 years. Psychopathology in their 2202 first-degree relatives was assessed with semistructured direct and family history interviews, and best-estimate diagnoses were derived with the use of all available data. Result: The relatives of adolescents with MDD exhibited significantly elevated rates of MDD (hazard ratio [HR], 1.77; 95% confidence interval [CI], 1.46-2.31), dysthymia (HR, 1.79; 95% CI, 1.11-2.87), and alcohol abuse or dependence (HR, 1.29; 95% CI, 1.05-1.53), but not anxiety disorders, drug abuse or dependence, or antisocial and borderline personality disorder. In contrast, anxiety, substance use, and disruptive behavior disorders in adolescents were not associated with elevated rates of MDD in relatives. However, the relatives of probands with anxiety and substance use disorders exhibited elevated rates of anxiety and substance use disorders, respectively. Conclusions: The results provide evidence of the familial aggregation of adolescent MDD, and also indicate that there is a considerable specificity in the pattern of familial transmission. In addition, we found preliminary evidence of the familial aggregation of adolescent anxiety and substance use disorders.