Exercise serves as a decent and effective treatment for teen depression, suggests a recent analysis of data from multiple studies over three decades.

For those of you that didn't already know, regular exercise has been shown to treat adult depression and anxiety, maybe just as well as psychotherapy or antidepressants. This is why I now routinely "prescribe" exercise to my depressed and anxious young adult patients.  And, yes, reader, this means that you, too, MIGHT save thousands of dollars in therapy bills in exchange for hundreds of dollars for a gym membership or a pair of running shoes.  The recommended "dose" of exercise for better mental health is 30 minutes, five times a week.  Fast walks count! So just do it! Your brain will thank you – and so will your dog.

The research evidence on exercise's positive mental health effects on teens and children is less strong, but that is likely because fewer studies have been completed in child populations. But the evidence that exercise is related to improved mental health in children is accumulating.

The latest study,  known as a meta-analysis — a statistical technique for synthesizing data from several smaller studies to determine findings that none could conclude on their own — examined trends in research data going back over 30 years and was  published in the Journal of the American Academy of Child and Adolescent Psychiatry. It joins  three  others on the same topic published in very good journals in the last three years. 

The most recent study on the benefits of exercise for teens is the strongest of the bunch because it included only data from previous studies where groups were assigned randomly to an exercise “treatment” or to another group (wait-list, psychotherapy-as-usual). These are called “randomized controlled studies” and are considered the best design for teasing out cause and effect. Based on the combination of statistical results from 8 such “gold standard” studies published between 1982-2015, the authors concluded that mild-to-moderate, group-based, supervised physical activity, three times a week for 6-12 weeks, can improve mild to severe depression in teens aged 13-17.

Why might exercise "work" as a mental health treatment? Various theories put forward in the research literature include:

1. Exercise reliably induces a positive mood. And it's hard to feel depressed when you're feeling positive (at least five times a week).

2. The practice of exercising regularly increases your sense of self-esteem. It's hard to feel bad about yourself when you are being such a disciplined go-getter.

3. Exercise might regulate important chemicals in the brain that are related to depression and anxiety. This is similar to the proposed mechanism of antidepressant medications, but without the side effects.

4. Regular exercise gets you accustomed to tolerating unpleasant physical sensations of the sort that mimic anxiety, such as pounding heart, labored breathing, and feeling hot and sweaty. In other words, you become much more comfortable being uncomfortable.

5. Regular exercise makes you sleep better. Less tired = less depressed.

As a child psychotherapist, I see a lot of depressed teens. Given the increasing evidence that exercise is an effective treatment for depression, perhaps I would do well to take my patients outside and combine their psychotherapy sessions with a brisk walk or even a light run. Double the therapy! Double the joy!

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