Yoga for posttraumatic stress disorder - a systematic review and meta-analysis

Background: Yoga is increasingly used as a therapeutic treatment and seems to improve psychiatric conditions such as anxiety disorders and depression. The aim of this systematic review was to assess the evidence of yoga for reducing symptoms of posttraumatic stress disorder (PTSD). Methods: The Cochrane Library, Medline/PubMed, PsycINFO, Scopus, and IndMED were searched through July 2017 for randomized controlled trials (RCTs) assessing the effects of yoga on symptoms of PTSD. Mean differences (MD) and standardized mean differences (SMD) with 95% confidence intervals (CI) were computed. The quality of evidence and the strength of recommendation were graded according to the GRADE recommendations. Results: Seven RCTs (N = 284) were included. Meta-analysis revealed low quality evidence for clinically relevant effects of yoga on PTSD symptoms compared to no treatment (SMD = -1.10, 95% CI [-1.72, -0.47], p<.001, I-2 = 72%; MD=-13.11, 95% CI [-17.95, -8.27]); and very low evidence for comparable effects of yoga and attention control interventions (SMD = -0.31, 95% CI = [-0.84, 0.22], p=.25; I-2 = 43%). Very low evidence was found for comparable retention of patients in the trial for yoga and no treatment (OR = 0.68, 95% CI [0.06, 7.72]) or attention control interventions (OR = 0.66, 95% CI [0.10, 4.46]). No serious adverse events were reported. Limitations: Few RCTs with only limited sample size were available. Conclusions: Only a weak recommendation for yoga as an adjunctive intervention for PTSD can be made. More high quality research is needed to confirm or disconfirm these findings.