Racial and ethnic differences in the association between obesity and depression in women

It is generally accepted that obesity and depression are positively related in women. Very little prior research, however, has examined potential variation in this relationship across different racial/ethnic groups. This paper examines the association between obesity and depression in non-Hispanic White, non-Hispanic Black, and Mexican American women.

The sample included women aged 20 years and older in the 2005-2008 National Health and Nutrition Examination Surveys (n=3666). Logistic regression was used to assess the relationship between obesity and depression syndrome (assessed using the Patient Health Questionnaire-9), after adjusting for covariates. We then investigated whether this association varied by race/ethnicity.

Overall, obese women showed a 73% greater odds of depression (odds ratio [OR]=1.73; 95% confidence interval [CI]=1.19, 2.53) compared with normal weight women. This association varied significantly, however, by race/ethnicity. The obesity-depression associations for both Black and Mexican American women were different from the positive association found for White women (ORBlack*obese=0.24; 95% CI=0.10,0.54; ORMexican American*obese=0.42; 95% CI=1.04). Among White women, obesity was associated with significantly greater likelihood of depression (OR=2.37; 95% CI=1.41, 4.00) compared to normal weight. Among Black women, although not statistically significant, results are suggestive that obesity was inversely associated with depression (OR=0.56; 95% CI=0.28, 1.12) relative to normal weight. Among Mexican American women, obesity was not associated with depression (OR=1.01; 95% CI=0.59, 1.72).

The results reveal that the association between obesity and depression varies by racial/ethnic categorization. White, but not Black or Mexican American women showed a positive association. Next research steps could include examination of factors that vary by race/ethnicity that may link obesity to depression.