Review: Exercise for depression in children and adolescents - a systematic review and meta-analysis.

Background: The objective of this systematic review was to examine the treatment effects of exercise on children and adolescents with depression compared to either other nonexercise treatments or no treatment. A study protocol was registered in PROSPERO (CRD42018101982).

Method: Cochrane Central Register of Controlled Trials (CENTRAL), Medline (Ovid), Embase (Ovid), PsycINFO (Ovid), AMED (Ovid), SPORTDiscus, PEDro, CINAHL (EBSCO), ERIC (EBSCO), Web of Science, and databases for grey literature and dissertations were searched from their inception through 30 August 2020 for randomized controlled trials. Varieties of search terms for depression, children and adolescents, exercise, and study design were applied. No limits were placed on publication year, language or publication type. Registers for ongoing trials were also searched. Two authors independently screened references, extracted data and assessed risk of bias in the included trials. The effect sizes for depression postintervention were pooled in a meta-analysis, and the certainty of the evidence was assessed using GRADE (Grading of Recommendations Assessments, Development, and Evaluation).

Results: 13,307 references were screened. Four trials were included (n = 159). Participants were between 12 and 18 years old, and predominantly female. A meta-analysis with a random-effects model was performed, and a moderate effect in favour of exercise on postintervention depression severity was identified (SMD = -0.59, 95% CI = -1.08 to -0.10, p = .02). However, the overall certainty of the evidence for this outcome was low. One trial found a nonsignificant decrease in depression severity at six-month follow-up (n = 42, SMD = -0.59, 95% CI = -1.22 to 0.04, p = 0.07), and the overall certainty of the evidence for this outcome was very low. One trial found no statistically significant differences between the exercise and control groups on quality of life. Other outcomes, including adverse events, psychological well-being and social functioning, were not evaluated.

Conclusion: Low certainty evidence suggests that exercise interventions may be associated with a decrease in adolescent depression severity. However, our confidence in the effect estimate is limited, and the true effect may be substantially different. Thus, large, high-quality trials including follow-up periods are needed.