The effect of physical activity on the association between perceived racial discrimination and depression in African Americans

Background: : The purpose of this cross-sectional study was to examine the effect of physical activity (PA) on the relationship between perceived racial discrimination and major depressive disorder (MDD) in African Americans. Methods: : 645 African Americans (mean age 45 years) were interviewed on their perceived racial discrimination, PA, and past 12-month MDD. Participants were categorized into tertiles (lower, middle, upper) of racial discrimination as well as "active" or "inactive" groups based on the US PA guidelines. Odds ratios and 95% confidence intervals (CIs) were calculated for MDD prevalence across discrimination tertiles stratified by PA group after adjusting for potential confounders. Results: : The upper (higher) discrimination group had 2.99 (95% CIs 1.03-8.67) increased odds of MDD compared with the lower group after adjusting for potential confounders. The stratified analysis indicated that the increased odds of MDD in the upper discrimination group were observed only among the inactive group (5.19 [1.08-24.87]) after adjusting for age and sex. The association between discrimination and MDD was not significant among active participants. Limitations: : Limitations include generalizability since participants were predominantly women and recruited solely from Iowa or Georgia; the low number of MDD cases in some groups; and that causation cannot be inferred from this cross-sectional study. Conclusion: : Not meeting the PA guidelines may be associated with higher depression among African Americans experiencing higher levels of perceived racial discrimination.