Review of: Recchia F et al, JAMA Pediatrics 2023;177(2):132–140

Study Type: Systematic review and meta-analysis

We often look for ways beyond medication and therapy to help manage depression in young people, especially because these traditional methods can have drawbacks like side effects or lack of engagement. This is where physical activity could be useful as an adjunctive modality. The 2023 AACAP Clinical Practice Guidelines for Depressive Disorders concluded there was “insufficient rigorous evidence of benefit for…exercise” (Walter HJ et al, J Am Acad Child Adolesc Psychiatr 2023;62(5):479–502). Let’s dig into some recent findings on this.

This comprehensive review brought together data from 21 studies, including 17 randomized controlled trials. These studies investigated the effects of aerobic-type physical activity lasting at least four weeks, though the average was about 22 weeks. The sessions typically lasted 50 minutes and occurred three times a week. The researchers were particularly focused on how these activities impacted depressive symptoms in children and adolescents as measured by validated scales.

Overall, 2,441 participants (53% girls, average age of 14 years) took part. Physical activity interventions reduced depressive symptoms to a statistically significant degree, although the mean effect size was small (Hedges’ g=-0.29; p=0.004) (Editor’s note: For Hedges’ g effect size, 0.15 is considered small, 0.40 is medium, and 0.75 is large). The number needed to treat (NNT) was 6, which means that for every seven kids who participate in such a program, one would likely see improvement in their depressive symptoms—for most treatments, an NNT of 5 is considered meaningful.

Several factors influenced the effectiveness of the interventions:

• Intervention characteristics: Programs that were less supervised and shorter in duration (less than 12 weeks) tended to have a stronger effect.
• Participant characteristics: Older adolescents (over 13 years) and those with a clinical diagnosis of mental illness or depression benefited the most from the physical ­activity.

Carlat Take

This study offers limited support for using structured physical activity to manage depression, particularly among teens. But it’s more than getting kids moving; we need to understand who benefits and how to tailor interventions to be most effective. We need more research to clarify parameters—such as frequency, duration, and supervision—and to understand the impact of other factors such as co-occurring conditions and social determinants of health. Still, keep exercise in mind as some patients may respond well.