Physical activity and mortality in the general population with and without major depression

Background and aims: It is not yet well understood whether physical activity (PA) may protect against elevated mortality in major depression. Answering this question has implications for policy and practice. The aim of this study was to estimate the association of PA with mortality in major depressive disorder (MDD). Methods: We used data from the Canadian Community Health Survey—Mental Health and Well-Being (CCHS 2002), conducted in 2002 (n = 31,200), and the Canadian Community Health Survey—Mental Health (CCHS-MH 2012), conducted in 2012 (n = 20,935), for this analysis. Recreational PA was measured using metabolic equivalent of task (MET) values, classifying participants as active, moderately active, and physically inactive in the 2002 survey and as very active, active, moderately active, and physically inactive in the 2012 survey. Major depression was assessed using a fully structured diagnostic instrument, the Composite International Diagnostic Interview. Mortality data was obtained through data linkage. The analysis used Cox proportional hazard models to explore the associations. Results: PA in the 2002 survey was protective: HR 0.69 (95% CI 0.64–0.74) and HR 0.77 (95% CI 0.72–0.83) for the active and moderately active groups, respectively. In the 2012 survey, the HRs were 0.55 (95% CI 0.43–0.70), 0.57 (95% CI 0.43–0.75), and 0.59 (95% CI 0.46–0.76) for the very active, active, and moderately active groups, respectively. No interactions were significant. Conclusions: These results indicate that PA protects against elevated mortality to the same extent in those with MDD as in those without. These findings, which arise from a representative sample, support continued efforts to integrate PA into the management of depressive disorders at the population level.