The belief that exercise is a simple, non-pharmacological treatment for depression is so attractive, that it’s been received pretty much uncritically. When a study last year seemed to question the use of exercise as an ‘add-on’ treatment for depression, there was a mini-outcry, with many people (including people who’ve had depression) loudly proclaiming how much it helps them.
There’s little doubt that being physically active is good for mental health. I rarely feel so positive, healthy and raring to go as when I’ve just completed a run, swim or cycle ride. For me, exercising outdoors is even better – I’d rather splash through the rain in my muddy trainers than pound a gym treadmill. And I know that too little outdoors time, too little exercise, makes me feel sluggish, irritable and prone to disgruntlement.
And yet I suspect there’s a chicken/egg situation here. Do I feel great because I went running, or did I go running because I woke up in a positive frame of mind? If I’d been lying awake all night worrying, would I have just pulled the duvet back over my head? Does exercise make you happy, or do happy people exercise?
When pondering these questions, I’m always happy to see that the Cochrane Collaboration have got there first. Cochrane run systematic reviews of published clinical studies to assess the effectiveness of treatments on a massive range of conditions. They recently updated their review on exercise as a treatment for depression. The results were mixed.
Taking all the studies together, there seemed to be an improvement in the symptoms of people with depression who exercised. However, many of the studies looking at exercise are small and have methodological problems. The main difficulty is ‘blinding’ – it’s impossible to conceal from someone whether they are exercising or not. This means you have to allow for a placebo effect, where people expect to feel better if they exercise.
When the Cochrane reviewers looked just at the bigger, better quality studies, the positive effects of exercise pretty much vanished. Some of the studies compared exercise with other treatments such as antidepressants or talking therapies. The results were similar, which could be read as a good thing if we could conclude that exercise works as well as the pills. However, the best we can really say from these studies is that they don’t work better than the pills or talking therapy. (For more on the study, see the summary on the Best Health website, by my colleague Grant Stewart).
Here’s my hunch. Exercise works well to keep healthy people healthy, both in body and mind. If you’ve been ill, gentle exercise can help you recover and may prevent a relapse. But exercise as a panacea for people in the pit of depression? If only. Anyone who has ever been there, who knows that some days it’s impossible even to eat or talk, will know that being told to go for a brisk walk is about as much use as being told to pull yourself together. Let’s not let our enthusiasm for healthy living outweigh our compassion for people with a serious, debilitating illness. Worse, let’s not fool ourselves that such serious, complex illnesses as depression can be cured by the cheap option alone.
UPDATE: for a great analysis in more depth, see this article by Andre Tomlin on The Mental Elf.