This week’s news headlines making out that exercise is ineffective in treating depression have not just been disappointing, we’re concerned there’s a danger that at best they’ll neutralise positive health messages and the efforts of the fitness industry, and at worse discourage those people who drag themselves off to the gym in order to tackle the infamous black dog. This might be acceptable if the headlines were accurate, but they’re not. Here we address the problems with the claims.
It all started when an article published in the British Medical Journal reported on a study by researchers at
Another study, one done in the US in 1999/2000 had already found that adding exercise to antidepressants to treat adults with depression was not just ineffective in the longer term, but that exercise without antidepressants was actually more effective than the combined treatment (of exercise plus antidepressants), or antidepressants alone. So unless, the British research team intended to replicate or improve on this study, why they wanted to add physical activity to the usual treatment for depression is a bit of a mystery.
The problem is, it’s not clear who exercised and who didn’t, indeed it seems that both groups exercised. The British study calls itself a randomised control trial of facilitated physical activity for the treatment of depressed patients, but it only controlled for the PAF advice not the actual physical activity. Indeed, as the usual treatment for depression may include exercise, and just under half of the ‘usual care’ group were physically active when the study began, it’s possible that many participants in both groups partook in physical activity. It’s also unclear how many achieved the desired 150 minutes per week at the correct intensity (even though some of the participants kept an activity diary, and for a brief period, a small number used a pedometer-type of device to record some physical activity) especially when anyone complaining that the exercise was “unrealistic” was encouraged to just increase their physical activity. As the study simply compares the data from both groups (each comprising exercisers and non-exercisers) it doesn’t assess the affect of exercise on depression, and it doesn’t assess whether physical activity (facilitated or otherwise) is an effective addition to the usual treatment.
The issue of not controlling for exercise aside, even if we focus on understanding how effective the PAF was, it’s important to note that in addition to their usual treatment, the second group was only offered up to three face-to-face appointments and ten telephone appointments with a PAF. Many did not actually have all thirteen appointments. Interestingly, the researchers didn’t expect the participants to attend all the appointments on offer, but they did determine that an “adequate dose” would be the take up of a minimum of five PAF sessions including at least one face-to-face session. Yet, after four months of first being offered it, only just over half of them had taken up the minimum number of sessions, and by the end of their participation in the study nearly a third of the group still hadn’t had the adequate dose. With such a high proportion of the participants not complying with the treatment, we are doubtful that the researchers can even determine the effectiveness of the PAF.
Had the British researchers designed their study differently, it could have been a different story. We might have been clearer about the effectiveness of exercise in treating depression, and we might have been clearer about whether exercise advisors helped patients stick to their exercise programme. Perhaps they should have involved the fitness industry in the study design and execution – I’m sure they would have been only too happy to help demonstrate the effects of exercise on mental health.
Babyak, M. A., Blumenthal, J. A., Herman, S., Khatri, P., Doraiswamy, P. M., Moore, K. A., Craighead, W. E., Baldewicz, T. T., & Krishnan, K. R. (2000). Exercise treatment for major depression: Maintenance of therapeutic benefit at 10 months. Psychosomatic Medicine, 62, 633-638.
Blumenthal, J. A., Babyak, M.A., Moore, K. A., Craighead, W. E., Herman, S., Khatri, P., Waugh, R., Napolitano, M. A., Forman, L. M., Appelbaum, M., Doraiswamy, P. M., & Krishnan, K. R. (1999). Effects of exercise training on older patients with major depression. Archives of Internal Medicine, 159, 2349-2356.
Chalder M., Wiles N.J.,
Chalder, M., Wiles, N.J.,
Jeffreys, B. (June 6, 2012). Depression: Exercise no help for depression. BBC News. Retrieved 06/06/12 from http://www.bbc.co.uk/news/health-18335173
Press Association. (June 6, 2012). Exercise doesn’t help depression, study concludes. The Guardian. Retrieved 06/06/12 from http://www.guardian.co.uk/society/2012/jun/06/exercise-doesnt-help-depression-study
Radnedge, A. (June 6, 2012). Exercise ‘is not effective in treating depression’. Metro. Retrieved 06/06/12 from http://www.metro.co.uk/news/901138-exercise-is-not-effective-in-treating-depression