The effect of Tai Chi and Qigong practice on depression and anxiety symptoms: A systematic review and meta-regression analysis of randomized controlled trials

Background: We extend findings from previous quantitative reviews of the effects of Tai Chi and Qigong exercises on symptoms of depression and anxiety in randomized controlled trials by examining whether effects varied according to participant characteristics, exposure, or features of research design. Methods: Thirty-five articles published before 1 April 2013 involving 2765 participants were selected according to PRISMA guidelines. Hedges d effect sizes were calculated and random effects models were used to estimate population variance of the observed effects and its moderators using meta-regression analysis. Results: Tai Chi training reduced depression by a heterogeneous standardized mean effect size 0.36 (95% CI, 0.19-0.53); reductions were larger in participants having elevated symptoms at baseline. Studies with blinded allocation of participants had smaller effects. The homogeneous mean effect of Qigong on depression was 0.38 (95% CI = 0.25-0.51). The heterogeneous mean effect of Tai Chi on anxiety was 0.34 (95% CI = 0.02-0.66); reductions were larger when participants were Asian and smaller when they were older. The heterogeneous mean effect of Qigong on anxiety was 0.72 (95% CI = 0.4-1.03); reductions were inversely related to age and positively related to session duration and weekly frequency. Conclusion: Tai Chi and Qigong exercises have small-to-moderate efficacy for reducing symptoms of depression and anxiety. Higher-quality trials are needed that sample patients with elevated symptoms, use blinded allocation to conditions, and standardize Tai Chi and Qigong exposure in order to better determine clinical effectiveness and its modifiers. (C) 2014 Elsevier Ltd. All rights reserved.