This meta-analysis revealed overall increased mortality of up to 25% in patients experiencing depressive symptoms after cancer diagnosis (risk ratio [RR] unadjusted = 1.25; 95% confidence interval [CI], 1.12 to 1.40; P < .001), and a 39% higher risk in patients diagnosed with major or minor depression after cancer diagnosis (RR unadjusted = 1.39; 95% CI, 1.03-1.89; P = .033), based on 25 independent studies. Given the scarce number of relevant studies available to date, the effect of depressive symptoms on cancer recurrence did not reach significance (RR unadjusted = 1.23; 95% CI, 0.85-1.77; P = .275, k = 3).
