Effects of yoga on depressive symptoms in people with mental disorders : a systematic review and meta-analysis

Objective To assess whether physically active yoga is superior to waitlist control, treatment as usual and attention control in alleviating depressive symptoms in people with a diagnosed mental disorder recognised by the Diagnostic and Statistical Manual of Mental Disorders (DSM). Design Systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data sources Data were obtained from online databases (MEDLINE, EMBASE, PsychINFO, CENTRAL, EMCARE, PEDro). The search and collection of eligible studies was conducted up to 14 May 2019 (PROSPERO registration No CRD42018090441). Eligibility criteria for selecting studies We included randomised controlled trials with a yoga intervention comprising ≥50% physical activity in adults with a recognised diagnosed mental disorder according to DSM-3, 4 or 5. Results 19 studies were included in the review (1080 participants) and 13 studies were included in the meta-analysis (632 participants). Disorders of depression, post-traumatic stress, schizophrenia, anxiety, alcohol dependence and bipolar were included. Yoga showed greater reductions in depressive symptoms than waitlist, treatment as usual and attention control (standardised mean difference=0.41; 95% CI -0.65 to -0.17; p<0.001). Greater reductions in depressive symptoms were associated with higher frequency of yoga sessions per week (β=-0.44, p<0.01).