One of the first major studies in the area, by John Greist, MD, in 1978 found that exercise by itself was as or more effective in lowering symptoms among depressed patients than therapy. For depressed patients, exercise provides a basic sense of accomplishment, says John Silva, PhD, professor of sport psychology at the University of North Carolina at Chapel Hill. In addition, exercise can give depressed people nonthreatening social support, Silva said. Exercise can short-circuit the cycle of cognitive and physical tension that characterizes anxiety disorders, Silva said. If you can dissipate the somatic anxiety through exercise, you're not sending as many cues to the brain that you're highly anxious.
Exercise provides a kind of mental 'time out' that gives the body a break, too.
Instead of medication Practitioners are using exercise with more seriously mentally ill clients, too. Martinsen successfully uses exercise as an adjunct to therapy with schizophrenic and manic-depressive patients. He believes it works well because it puts a part of their treatment into their own hands. Exercise is a practical way to show them that their own work, their own efforts, are important for their outcome. While the benefits of exercise are manyfold, Hays advises clinicians to be cautious when incorporating it as part of treatment.