Yoga-based interventions may reduce anxiety symptoms in anxiety disorders and depression symptoms in depressive disorders: a systematic review with meta-analysis and meta-regression

Objective To summarise the effect of mind–body exercises on anxiety and depression symptoms in adults with anxiety or depressive disorders. Design Systematic review with meta-analysis and meta-regression. Data sources Five electronic databases were searched from inception to July 2022. Manual searches were conducted to explore clinical trial protocols, secondary analyses of clinical trials and related systematic reviews. Eligibility criteria Randomised clinical trials evaluating qigong, tai chi or yoga styles with anxiety or depression symptoms as the outcomes were included. No intervention, waitlist or active controls were considered as control groups. The risk of bias and the certainty of the evidence were assessed. Meta-analyses, meta-regressions and sensitivity analyses were performed. Results 23 studies, comprising 22 different samples (n=1420), were included. Overall, meta-analyses showed yoga interventions were superior to controls in reducing anxiety symptoms in anxiety disorders. Furthermore, yoga-based interventions decreased depression symptoms in depressive disorders after conducting sensitivity analyses. No differences between groups were found in the rest of the comparisons. However, the certainty of the evidence was judged as very low for all outcomes due to concerns of high risk of bias, indirectness of the evidence, inconsistency and imprecision of the results. In addition, there was marked heterogeneity among yoga-based interventions and self-reported tools used to evaluate the outcomes of interest. Conclusion Although yoga-based interventions may help to improve mental health in adults diagnosed with anxiety or depressive disorders, methodological improvements are needed to advance the quality of clinical trials in this field. PROSPERO registration number CRD42022347673.