Major depressive episodes and mortality in the Canadian household population

•The association of major depression with mortality is not restricted to clinical samples, it is evident in the general population (albeit with smaller hazard ratios), reflecting the spectrum of MDE.•The analysis provides evidence that behavioral and clinical variables that are associated with major depression contribute to the strength of association between major depression and mortality.•Even with control of an extensive list of covariates, and association of major depression and mortality persisted, but the strength of the association was attenuated. To explore the association between major depressive episodes (MDE) and subsequent mortality in a representative sample of the general household population, with adjustment for other determinants of mortality. The analysis used four datasets from the Canadian Community Health Survey (CCHS); the CCHS 1.1 (conducted in 2000 and 2001), the CCHS 1.2 (conducted in 2002), the CCHS 2.1 (conducted in 2003 and 2004) and the CCHS 3.1 (conducted in 2005 and 2006). Each survey included an assessment of past-year major depressive episodes (MDEs) and was linked to mortality data from the Canadian Mortality Database for January 1, 2000 to December 31, 2011. The hazard ratio (HR) for all-cause mortality was estimated in each survey sample. Random effects, individual-level meta-analysis was used to pool estimates from the four survey data sets. Estimates were adjusted for other determinants of mortality prior to pooling in order to help quantify the independent contribution of MDE to all-cause mortality. The unadjusted HR was 0.77 (95% CI 0.63–0.95). A naïve interpretation of this HR suggests a protective effect of MDE, but the estimate was found to be strongly confounded by age (age adjusted HR for MDE: 1.61, 95% CI 1. 34–1.93) and by sex (sex adjusted HR for MDE: 1.15, 95% CI 0.75–1.77). The age and sex adjusted HR was: 1.70 (95% CI 1.45–2.00). No evidence of effect modification by any determinant of mortality was found, including sex. After adjustment for a set of mortality risk factors, the pooled HR was weakened, but remained statistically significant, HR = 1.29 (I-squared =