Obesity was significantly associated with any mood disorder (OR 1.23), major depressive disorder (OR 1.27), any anxiety disorder (OR 1.46), and most strongly with some individual anxiety disorders such as post-traumatic stress disorder (PTSD) (OR 2.64). Sociodemographic correlates moderated the association between obesity and mood disorders but were less influential in obesity-anxiety disorder associations. Adjustment for the comorbidity between anxiety and mood disorders made little difference to the relationship between obesity and anxiety disorders (OR 1.36) but rendered the association between obesity and mood disorders insignificant (OR 1.05).
Stronger associations were observed between anxiety disorders and obesity than between mood disorders and obesity; the association between PTSD and obesity is a novel finding. These findings are interpreted in light of research on the role of anxiety in eating pathology, and deserve the further attention of researchers and clinicians.
Obesity (defined as body mass index [calculated as weight in kilograms divided by the square of height in meters] of > or =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). Subgroup 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).
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.