Yoga is an ancient spiritual practice that originated in India and is currently accepted in the Western world as a form of relaxation and exercise. It has been of interest for people with schizophrenia to determine its efficacy as an adjunct to standard-care treatment.
To examine the effects of yoga versus standard care for people with schizophrenia.
We searched the Cochrane Schizophrenia Group Trials Register (November 2012 and January 29, 2015), which is based on regular searches of MEDLINE, PubMed, EMBASE, CINAHL, BIOSIS, AMED, PsycINFO, and registries of clinical trials. We searched the references of all included studies. There were no language, date, document type, or publication status limitations for inclusion of records in the register.
All randomised controlled trials (RCTs) including people with schizophrenia comparing yoga to standard-care control.
The review team independently selected studies, quality rated these, and extracted data. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For continuous data, we estimated the mean difference (MD) between groups and its 95% CI. We employed mixed-effect and fixed-effect models for analyses. We examined data for heterogeneity (I(2) technique), assessed risk of bias for included studies, and created 'Summary of findings' tables using GRADE (Grading of Recommendations Assessment, Development and Evaluation).
We included eight studies in the review. All outcomes were short term (less than six months). There were clear differences in a number of outcomes in favour of the yoga group, although these were based on one study each, with the exception of leaving the study early. These included mental state (improvement in Positive and Negative Syndrome Scale, 1 RCT, n = 83, RR 0.70 CI 0.55 to 0.88, medium-quality evidence), social functioning (improvement in Social Occupational Functioning Scale, 1 RCT, n = 83, RR 0.88 CI 0.77 to 1, medium-quality evidence), quality of life (average change 36-Item Short Form Survey (SF-36) quality-of-life subscale, 1 RCT, n = 60, MD 15.50, 95% CI 4.27 to 26.73, low-quality evidence), and leaving the study early (8 RCTs, n = 457, RR 0.91 CI 0.6 to 1.37, medium-quality evidence). For the outcome of physical health, there was not a clear difference between groups (average change SF-36 physical-health subscale, 1 RCT, n = 60, MD 6.60, 95% CI -2.44 to 15.64, low-quality evidence). Only one study reported adverse effects, finding no incidence of adverse events in either treatment group. This review was subject to a considerable number of missing outcomes, which included global state, change in cognition, costs of care, effect on standard care, service intervention, disability, and activities of daily living.
Even though we found some positive evidence in favour of yoga over standard-care control, this should be interpreted cautiously in view of outcomes largely based each on one study with limited sample sizes and short-term follow-up. Overall, many outcomes were not reported and evidence presented in this review is of low to moderate quality - -too weak to indicate that yoga is superior to standard-care control for the management of schizophrenia.