To the Editor Dr Cooney and colleagues1 provided a concise summary of their recent meta-analysis of exercise for depression, but careful examination of their data raises concerns about the validity of their analysis and interpretation of results. The Figure indicates that 13 of 16 studies favored exercise—an 81% positive rate; the overall effect size was moderate (5-point improvement on a depression scale) favoring exercise. To put this in perspective, an analysis of 74 trials of 12 antidepressant agents involving 12 564 patients submitted to the US Food and Drug Administration2 reported that only 51% of trials showed a positive benefit for antidepressants over placebo. Most antidepressants only show a 2- to 3-point superiority over placebo on depression rating scales.
Blumenthal JA, Doraiswamy PM. Exercise to Combat Depression. JAMA. 2014;312(20):2166-2167. doi:10.1001/jama.2014.14334