Effects of a school-based physical activity intervention on mental health indicators in a sample of Brazilian adolescents: a cluster randomized controlled trial.

Abstract

Purpose: To test the effects of a physical activity intervention program on symptoms of mental disorders among adolescents.

Methods: This study is a 12-week cluster randomized controlled trial. The sample consisted of 306 adolescents (45,8% male, age: 13,6 [0,72] years; 54.2% female, age: 13.5 [0.69] years), randomized into an intervention group (N = 165) and a control group (N = 141). The physical activity program involved sessions including muscle strengthening and cardiorespiratory exercises and lifestyle guidance. The mental health indicators analyzed were: anxiety, depression, sleep, and psychological well-being. Intervention effects were analyzed by generalized estimating equations.

Results: After 12 weeks, no significant improvements were observed in the intervention group for sleep; anxiety; depression, and psychological well-being. In the subgroup analysis, significant group×time interactions were observed for adolescents who were classified with moderate symptoms of depression (mean difference: -0.97, p = 0.002) and anxiety (mean difference: -3.03, p = 0.01) with favorable effects for intervention group.

Conclusion: After the 12-week intervention period, it can be concluded that 12 weeks of school-based physical activity intervention significantly reduced symptoms of anxiety and depression in adolescents with moderate/severe symptoms. Furthermore, the intervention contributed to the maintenance of psychological well-being, since the control group showed a significant reduction in this mental health indicator.