Physical activity can help relieve depressive symptoms in teens, according to a systematic review and meta-analysis of clinical trials.
Engaging in physical activity significantly helped reduce depressive symptoms, with a modest corrected effect size compared to controls (g= -0.29, 95% CI -0.47 to -0.10, s= 0.004), found Parco M. Siu, Ph.D. of the University of Hong Kong, and colleagues.
In all studies, the group reported that the benefits of physical activity in reducing depressive symptoms resulted in a number needed to treat six. JAMA Pediatrics.
But it appears that physical activity needs to keep up in order to reap these benefits. In the four studies examining follow-up outcomes at a median of 21 weeks after the intervention, significant differences in depressive symptoms disappeared (g= -0.39, 95% CI -1.01 to 0.24, s= 0.14). However, Siu’s group said this is “probably due to the limited number of studies with follow-up results.”
In a secondary analysis, the researchers found a few factors that might predict exactly who will reap the greatest mental health benefits from physical activity. For example, adolescents aged 13 or older (vs children under 13), those with a preexisting mental illness (vs considered “healthy” or physically ill), and those with a diagnosis of depression experienced the largest effect sizes. between physical activity and mental health.
The characteristics of the physical activity itself also seem to be important. Engaging in physical activity three times per week was associated with the greatest reduction in depressive symptoms, and the effect was greater when physical activity was unsupervised than when it was fully or partially moderated in studies. Also, studies in which the physical activity intervention lasted less than 12 weeks had a larger effect size.
The level of intensity (low to moderate versus vigorous) and the length of the activity session (less than 45 minutes versus 45 minutes or more) did not appear to play a role in the effect size of the outcome.
Siu group indicated a A recent cross-sectional study which found a U-shaped association between physical activity and mental health, suggesting that 10 to 15 sessions of physical activity per month was associated with the greatest mental health benefits.
“Mediators at the individual level who are statistically rationally determined that depressed adolescents and young adults may have higher baseline depressive symptoms (more room for improvement on the dependent variable) and lower levels of physical activity (more room for improvement on the independent variable),” he noted. accompanying editorial By Eduardo E. Bustamante, Ph.D. of the University of Illinois at Chicago, and colleagues.
“The finding that outcomes were less significant when the interventions were too frequent (or not frequent enough) and continued for too long (or not long enough) may reflect that part of the association of physical activity with decreased depression is the sense of accomplishment associated with their successful completion — namely, An advantage that requires achievable but challenging goals.”
A wide variety of physical activity programs were evaluated across the studies included in the meta-analysis, ranging from dance, swimming, sports, running, walking, the elliptical machine, exercise games, and more. The common denominator, though, was the focus on aerobic exercise.
Across the 21 studies included, the average age of the participants was 14 and 47% were male. The majority of included studies (17 of 21) were randomized controlled trials, and the remainder were non-randomized controlled trials.
Bustamante’s group concluded, “The evidence that physical activity is an effective drug for mental health is strong; now we need to find ways to get people to take it.”
The study was supported by a grant from the Health and Medical Research Fund of the Food and Health Bureau, the Government of the Hong Kong Special Administrative Region, and the Seed Fund for Basic Research of the University of Hong Kong.
Seo and co-authors reported no disclosures.
Bustamante and co-authors reported no disclosures.
Source Reference: Recchia F, et al “Physical activity interventions for alleviating depressive symptoms in children and adolescents” JAMA Pediatr 2022; DOI: 10.1001/jamapediatrics.2022.5090.
Source Reference: Bustamante EE, et al “Unlocking the promise of physical activity to promote mental health” JAMA Pediatr 2022; DOI: 10.1001/jamapediatrics.2022.5096.