Depressive symptoms during childhood and adult obesity: the Zurich Cohort Study.

Depression and obesity have become major health problems with increasing prevalence. Given the limited effectiveness of treatment for weight problems, the identification of novel, potentially modifiable risk factors may provide insights on new preventive approaches to obesity. The purpose of this study was to test the hypothesis that depressive symptoms during childhood are associated with weight gain and obesity during young adulthood. Participants were from a prospective community-based cohort study of young adults (N=591) followed between ages 19 and 40 years. The sample was stratified to increase the probability of somatic and psychological syndromes. Information was derived from six subsequent semistructured diagnostic interviews conducted by professionals over 20 years. The outcome measures were body mass index (BMI) and obesity (BMI>30). Among women, depressive symptoms before age 17 years were associated with increased weight gain (4.8 vs 2.6% BMI increase per 10 years) representing greater risk for adult obesity (hazard ratio=11.52, P<0.05). Among men, only after controlling for confounders, depressive symptoms before age 17 years were associated with increased weight gain (6.6 vs 5.2% BMI increase per 10 years) in adulthood but not with occurrence of obesity. These associations between childhood depressive symptoms and adult body weight were adjusted for baseline body weight, a family history of weight problems, levels of physical activity, consumption of alcohol and nicotine, and demographic variables. As the magnitude of the associations was high, and depression during childhood is a prevalent and treatable condition, this finding may have important clinical implications for the prevention and treatment of obesity. Whether the results of this study are limited to populations with elevated levels of psychopathology remains to be tested.