There have been some studies testing exercise for depression -- they compare exercise against no treatment or exercise against treatment.
When you only include well run studies you find minimal benefit for exercise vs no treatment -- it's a little bit better than not doing anything. There's no reason to expect this would be different for exercise vs treatment -- when you use good quality trials you will probably see very little benefit, and the benefit of actually getting a real fucking treatment is probably going to be better.
> Exercise is moderately more effective than a control intervention for reducing symptoms of depression, but analysis of methodologically robust trials only shows a smaller effect in favour of exercise. When compared to psychological or pharmacological therapies, exercise appears to be no more effective, though this conclusion is based on a few small trials.
When you only include well run studies you find minimal benefit for exercise vs no treatment -- it's a little bit better than not doing anything. There's no reason to expect this would be different for exercise vs treatment -- when you use good quality trials you will probably see very little benefit, and the benefit of actually getting a real fucking treatment is probably going to be better.
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD004366...
Here's the authors extract for clarity:
> Exercise is moderately more effective than a control intervention for reducing symptoms of depression, but analysis of methodologically robust trials only shows a smaller effect in favour of exercise. When compared to psychological or pharmacological therapies, exercise appears to be no more effective, though this conclusion is based on a few small trials.