Association between obesity and depressive disorder in adolescents at high risk for depression

OBJECTIVE: To examine the relationship between Body Mass Index (BMI) and depressive disorder in adolescents at high risk for depression. DESIGN: Prospective longitudinal 3-wave study of offspring of parents with recurrent depression. Replication in population-based cohort study. SUBJECTS: Three hundred and thirty-seven families where offspring were aged 9-17 years at baseline and 10-19 years at the final data point. Replication sample of adolescents from population-based cohort study aged 11-13 years at first assessment and 14-17 years at follow-up. MEASUREMENTS: High risk sample used BMI, skin-fold thickness, Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV)-defined major depressive disorder and depression symptoms using the Child and Adolescent Psychiatric Assessment (CAPA). Replication sample used BMI, DSM-IV depressive disorder and depression symptoms using the Development and Well-Being Assessment (DAWBA). RESULTS: Two hundred and eighty-nine adolescents were included in the primary analyses. The mean BMI for each age group in this sample were significantly higher than population norms. There was no significant longitudinal association between categories of weight (or BMI) and new onset depressive disorder or depression symptoms. Similar results were found for skin-fold thickness. The association was also tested in a replication population-based sample and found to be non-significant in the subsample of offspring with mothers who had experienced recurrent depression in the past. BMI at age 12 years was, however, a significant predictor of depression symptoms but not of depressive disorder at age 15 years for the total unselected population. CONCLUSION: BMI does not significantly predict the development of depression in the offspring of parents with recurrent depression.