Why don't doctors prescribe exercise for depression?

Here’s the most important thing I learned while writing a book on running and mental health: In clinical studies, regular aerobic exercise is as effective as antidepressants in reducing symptoms of mild to moderate depression. And that’s not just because moving might help you get into shape and feel better about yourself. Exercise actually causes the same structural changes to the brain as antidepressants—neuroplasticity, or creating new neural pathways, and growth in the hippocampus, a part of the brain that’s generally shrunken in people with depression.

Patients are excused for not knowing these facts. Doctors working in an evidence-based health care system shouldn’t be. Yet if you’ve seen an American doctor for mild or moderate depression and been told to try working out, you’re in the minority. Current guidelines by groups such as the American Psychiatric Association and the American College of Physicians don’t count exercise as an initial form of treatment a physician should recommend for a patient with depression. Instead, modern antidepressants and some forms of psychotherapy are the two main first-line treatments prescribed. The U.S. approach is captured nicely on a patient portion of the National Institute of Mental Health website discussing depression. It includes exercise in a section called “Beyond Treatment: Things You Can Do,” along with items like “set realistic goals for yourself” and “continue to educate yourself about depression.”