Perhaps it is not a chemical effect, perhaps getting out of the house, being in a group, or the pleasure of mastering new skills or seeing improvements in fitness levels makes a difference. All but one of the studies in the Cochrane review involved supervised exercise such as a class at a gym, while the new study simply recommended exercise of any kind – the authors explained that they “asked a pragmatic question concerning a feasible intervention that could be used in primary care.” The guidelines for the British organisation NICE which gathers evidence for the cost-effectiveness of different treatments are very specific in their recommendations, advising structured, supervised exercise programmes in groups, three times a week.
Finally, Professor William Morgan at the University of Wisconsin-Madison in the US has proposed a simple idea. It’s called the distraction hypothesis, and you’ve guessed it, the theory is that exercise relieves depression because it distracts us from worrying. He also found that the effect wears off after 24 hours, so we need to keep topping it up [Ref: Morgan, W. Physical Activity and Mental Health]. But his findings may be reassuring for anyone who’s not so keen on exercise. Sitting in a quiet room in a comfortable, old, leather armchair for a period of time seemed to make people feel just as good.
Whatever the reason, an important point to end with is that exercise may help, but it is not a panacea for depression. The nature of the condition means that after six months many people will feel better regardless of their treatment. Exercise isn’t going to cure the world of depression, but it is still worth a try. Ultimately, if it makes you feel better, then do it.
You can hear more Medical Myths on Health Check on the BBC World Service.
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