The efficacy of meditation-based mind-body interventions for mental disorders: A meta-review of 17 meta-analyses of randomized controlled trials

There is increasing interest in the potential efficacy of meditation-based mind-body interventions (MBIs) within mental health care. We conducted a systematic metareview of the published randomized control trial (RCT) evidence. MEDLINE/PubMed, PsycARTICLES and EMBASE were searched from inception to 06/2020 examining MBIs (mindfulness, qigong, tai chi, yoga) as add-on or monotherapy versus no treatment, minimal treatment and passive and active control conditions in people with a mental disorder. The quality of the methods of the included meta-analyses using A Measurement Tool to Assess Systematic Reviews (AMSTAR) and the methodological quality of the RCTs using AMSTAR-Plus. Sixteen (94%) of 17 meta-analyses had good overall methodological quality. The content validity of the included RCTs was considered good in 9 (53%) meta-analyses. In meta-analyses with good methodological quality (AMSTAR 8 <=) and content validity (AMSTAR+ 4 <=), large effect sizes (0.80 or higher) were observed for mindfulness in schizophrenia and in ADHD, a moderate (0.50 <= 0.80) effect size for mindfulness in PTSD and a small (0.20 < 0.50) effect size for yoga in schizophrenia No serious adverse events were reported (n RCTs = 43, n in the MBI arms = 1774), while the attrition rates were comparable with the rates in passive and active control conditions. Our meta-review demonstrates that mindfulness and to a lesser extent yoga may serve as an efficacious supplement to pharmacotherapy, and psychotherapy and can be complementary in healthy lifestyle interventions for people with mental disorders. Metaanalytic evidence of high methodological quality and content validity of included trials is currently lacking for qigong and tai chi.