Anti-depression therapy is often combined with sports. Backed up by studies, therapists have long reported that exercise can complement depression therapy. Now, some are asking whether sports alone might be enough for some patients to overcome depression.

If so, patients would no longer have to rely on counseling, which can last for years, and could forgo antidepressants. The advantages are obvious: There would be no side effects -- except perhaps for sports injuries such as sprained ankles and sore muscles.

In collaboration with scholars from Australia, Belgium, Britain, Sweden and Brazil, researchers from Potsdam University's Department of Sport and Health Sciences systematically reviewed 41 studies on the subject of exercise and depression for a meta-analysis published in February in the British Journal of Sports Medicine.

The authors conclude that sports can offer "a further evidence-based treatment option for the large amount of untreated individuals with depression, including individuals who refuse or cannot tolerate medication and/or psychotherapy." They add, however, that "given the high heterogeneity and mainly small and selected samples of the included studies, this requires individual decisions involving the treating physician to determine if and which conditions of exercise are the optimal treatment of choice while also recognising the potential synergistic effects of exercise in managing both physical and mental well-being."