Effect of Physical Exercise on Depressive Disorder: A Systematic Review with Meta-Analysis and Meta-Regression

Background: Physical exercise has emerged as a promising intervention for depressive disorder, yet its efficacy and optimal implementation remain under investigation. Ob-jective: To thoroughly assess the effectiveness of structured physical exercise as a con-ventional treatment for adults with depressive disorder. Methods: Adhering to PRISMA 2020 guidelines, a comprehensive literature search was conducted across PubMed/MEDLINE and institutional multi-databases. Peer-reviewed randomized controlled trials (RCTs) published between 2010 and 2025, studying adults diagnosed with depressive disorder under supervised exercise interventions, were se-lected. Methodological rigor was ensured through two independent reviewers. The in-fluence of moderating variables (workload and the instrument used to evaluate depres-sive disorder: instrument) was analyzed using meta-regression, and the pooled effect size was estimated using both frequentist and Bayesian meta-analyses. Results: From 15,542 screened records, 20 RCTs met the inclusion criteria. Workload accounts for 60% of the variance in the effect size, and instrument accounts the 15%. Supervised physical exercise significantly reduced depressive symptoms (standardized mean difference = 0.80; 95% CI: 0.57–1.03; I² = 59%). Robust Bayesian meta-analysis confirmed the consistency of these findings. Conclusion: Physical exercise serves as a valuable complement to traditional therapies for adults diagnosed with depressive disorder, resulting in clinically significant reductions in depressive symptoms.