Systematic Umbrella Review and Meta-Meta-Analysis: Effectiveness of Physical Activity in Improving Depression and Anxiety in Children and Adolescents.

Objective: Depression and anxiety are prevalent and rising in children and adolescents, prompting interest in exercise as a potential therapeutic intervention. The aim of this systematic umbrella review and meta-meta-analysis (a meta-analysis of meta-analyses) was to evaluate the effects of exercise on depression and anxiety symptoms in children and adolescents and to identify the most promising exercise-based approaches.

Method: This systematic umbrella review was preregistered (PROSPERO ID: CRD42024533558) and followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Preferred Reporting Items for Overviews of Reviews (PRIOR) guidelines. A search of 11 databases identified systematic reviews and meta-analyses of randomized controlled trials (RCTs) evaluating the effects of exercise (aerobic, resistance, mind-body exercise) on depression and anxiety symptoms in children and adolescents. Risk of bias was assessed using the A MeaSurement Tool to Assess systematic Reviews (AMSTAR-2) tool, and certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool. Meta-analyses were conducted to combine effect sizes, using random effects models. Subgroup analyses were performed to examine participant and intervention characteristics.

Results: A total of 21 systematic reviews (n = 375 RCTs, n = 38,117 participants 5-18 years of age) were included. Participants included those with various clinical conditions, including depression, psychosocial disorders, obesity, and cancer, as well as healthy individuals. The pooled analysis found moderate effect sizes favoring exercise for symptoms of depression (standardized mean difference [SMD] = -0.45, 95% CI = -0.59 to -0.31, I = 71.37%, p < .01, 180 RCTs, n = 34,490 participants) and anxiety (SMD = -0.39, 95% CI = -0.61 to -0.17, I = 68.1%, p < .01, n = 55 RCTs, n = 24,797 participants). Mixed exercise modes and moderate-intensity exercise had the largest effects on depression, whereas resistance exercise was most effective for symptoms of anxiety. Interventions that were <12 weeks were more effective for depression compared with those that were ≥12 weeks. Benefits were generally consistent across populations. The certainty of evidence was moderate for depression and low to moderate for anxiety.

Conclusion: This meta-meta-analysis finds that exercise reduces depression and anxiety symptoms in children and adolescents. These results suggest that structured exercise programs should be considered as part of comprehensive care approaches.