Effects of Exercise on Positive Symptoms, Negative Symptoms, and Depression in Patients with Schizophrenia: A Systematic Review and Meta-Analysis

This study was performed to evaluate the effects of exercise on positive and negative symptoms and depression in patients with schizophrenia through a systematic review and meta-analysis focusing on randomized controlled trials (RCTs). PubMed, Embase, CINAHL, MEDLINE, Cochrane Library, PsycINFO, and Web of Science were searched from their inception to 31 October 2022. We also conducted a manual search using Google Scholar. This meta-analysis was conducted according to the PRISMA guidelines. The methodological quality of the studies was assessed using the Cochrane risk-of-bias tool for randomized trials. To identify the cause of heterogeneity, subgroup analysis, meta-ANOVA, and meta-regression analyses were performed as moderator analyses. Fifteen studies were included. The meta-analysis (random-effects model) for overall exercise showed a medium significant effect (standardized mean difference [SMD] = −0.51, 95% confidence interval [CI]: −0.72 to −0.31) on negative symptoms, a small significant effect (SMD = −0.24, 95% CI: −0.43 to −0.04) on positive symptoms, and a nonsignificant effect (SMD = −0.87, 95% CI: −1.84 to 0.10) on depression. Our findings demonstrate that exercise can relieve the negative and positive symptoms of schizophrenia. However, the quality of some included studies was low, limiting our results for clear recommendations.