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 was to evaluate the effects of exercise on depression and anxiety symptoms in children and adolescents and identify the most promising exercise-based approaches. METHOD: This systematic umbrella review was preregistered (PROSPERO ID: CRD42024533558) and followed PRISMA and PRIOR guidelines. A search of 11 databases identified systematic reviews and meta-analyses of randomised 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 AMSTAR-2 tool and certainty of evidence was assessed using GRADE. Meta-analyses were conducted to combine effect sizes, using random effects models. Subgroup analyses were performed to examine participant and intervention characteristics. RESULTS: Twenty-one systematic reviews (n=375 RCTs, n=38,117 participants aged 5-18 years) were included. Participants had various clinical conditions including depression, psychosocial disorders, obesity, cancer, as well as healthy individuals. The pooled analysis found moderate effect sizes favouring exercise for symptoms of depression (SMD = -0.45 [95% CI, -0.59 to -0.31], I2 = 71.37%, p<0.01, 180 RCTs, n=34,490 participants) and anxiety (SMD = -0.39 [95% CI, -0.61 to -0.17], I2 = 68.1%, p<0.01, n=55 RCTs, n=24,797 participants). Mixed exercise modes and moderate-intensity exercise had the largest effects on depression, while resistance exercise was most effective for symptoms of anxiety. Interventions that were <12 weeks were more effective for depression compared with >=12-week interventions. 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.