Association between obesity and psychiatric disorders in the US adult population

Background: Epidemiologic data suggest an association between obesity and depression, but findings vary across studies and suggest a stronger relationship in women than men. Objective: To evaluate the relationship between obesity and a range of mood, anxiety, and substance use disorders in the US general population. Design: Cross-sectional epidemiologic survey. Setting: Nationally representative sample of US adults. Participants: A total of 9125 respondents who provided complete data on psychiatric disorder, height, and weight. Response rate was 70.9%. Main Outcome Measures: Participants completed an in-person interview, including assessment of a range of mental disorders (assessed using the World Health Organization Composite International Diagnostic Interview) and height and weight (by self-report). Results: Obesity (defined as body mass index [calculated as weight in kilograms divided by the square of height in meters] of >= 30) was associated with significant increases in lifetime diagnosis of major depression (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.09-1.35), bipolar disorder (OR, 1.47; 95% CI, 1.12-1.93), and panic disorder or agoraphobia (OR, 1.27; 95% CI, 1.01-1.60). Obesity was associated with significantly lower lifetime risk of substance use disorder(OR, 0.78; 95% CI, 0.65-0.93). Sub group analyses found no difference in these associations between men and women, but the association between obesity and mood disorder was strongest in non-Hispanic whites (OR, 1.38; 95% CI, 1.20-1.59) and college graduates (OR, 1.44; 95% CI, 1.14-1.81). Conclusions: Obesity is associated with an approximately 25% increase in odds of mood and anxiety disorders and an approximately 25% decrease in odds of substance use disorders. Variation across demographic groups suggests that social or cultural factors may moderate or mediate the association between obesity and mood disorder.