Yoga for Depressive Disorder: A Systematic Review and Meta-Analysis

Background: The prevalence of depression has been increasing sharply. Given the existing treatment gap and the high prevalence of nonresponders to conventional therapies, the potential of complementary medicine becomes clear. The effect of yoga on depression has already been studied, but its efficacy in manifest depressive disorders remains unclear. Objective: To update and evaluate the current state of evidence for yoga as a therapy option for depressive disorders. Methods: PubMed/Medline, Cochrane Library, Scopus, PsycINFO, and BASE were searched systematically. Randomized controlled trials (RCTs), including participants with depressive disorders, were eligible. Analyses were conducted for active and passive control groups separately and for subgroups of major depressive disorder (MDD) and mixed samples. The risk of bias was assessed using the Cochrane risk of bias tool 2.0. Primary outcomes were the severity of depression and remission rates, and secondary outcomes were health-related quality of life and adverse events. The quality of evidence was assessed according to Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Results: Twenty-four studies (n = 1395) were included; of those, 20 studies (n = 1333) were meta-analyzed. Yoga showed a statistically significant short-term effect on depression severity when compared to passive control (standardized mean difference [SMD] = -0.43, 95% confidence interval [CI] = [-0.80; -0.07]) but not when compared to active control (SMD = -0.22, 95% CI  = [-0.67; 0.23]). Regarding remission rates, statistically significant effects were observed when comparing yoga to passive (odds ratio [OR] = 3.20; 95% CI = [1.45; 7.10]) as well as to active control (OR = 2.04; 95% CI = [1.13; 3.69]). No differences on safety outcomes were observed for passive (OR = 1.00, 95% CI = [0.10; 9.98]) as well as for active control (OR  = 0.80, 95% CI = [0.08; 8.09]). The quality of evidence ranged from moderate to very low. Due to the heterogeneity of outcome reporting, no meta-analysis for quality of life was possible. Conclusion: Yoga is an effective therapy approach for reducing depression severity when compared to passive control and obtains higher remission rates when compared to active and passive controls. Quality of evidence is inconsistent, but given the positive risk-benefit ratio of the intervention and the urge for therapy options for depression, yoga should be considered as a possible treatment option, particularly for MDD patients.