Re: Facilitated physical activity as a treatment for depressed adults: randomised controlled trial
Our paper(1) has generated a great deal of interest and reporting in the media. We would like to respond to these comments and in particular clarify our own interpretation of the data and mention some of the outstanding questions the research did NOT ask.
The study compared a physical activity intervention plus usual care with usual care alone. The intervention did not lead to an improvement in depressive symptoms compared to usual care. As many correspondents have stated, we did not evaluate “exercise” or even “physical activity” but the possible effect of our intervention on depression. That said, our intervention did increase self-reported physical activity levels. We can reasonably conclude that our intervention should not be widely adopted for treating depression.
The next question is whether general practitioners (GPs) should advise their patients with depression to become more physically active? Our argument would be that advice to be physical active alone is unlikely to improve depressive symptoms, after all our more intensive facilitated intervention was ineffective. On the other hand, all of us should be physically active because of the other well described health benefits. GPs should be advising all of us, including those with depression, to be physically active taking individual health and circumstances into account but on average, we would not expect that to improve depressive symptoms.
Many of the rapid responses to the BMJ have pointed out that giving advice to be physically active is not the same as following that advice. What if someone with depression does substantially increase their activity levels? Would this increase in physical activity lead to an improvement in depressive symptoms? Even though our intervention increased physical activity levels, we do not know if there is physical activity of the “right” intensity, duration or frequency that might benefit depression. Comments have advocated both higher intensities (as suggested in the rapid response by Larkin et al) and lower intensities (as suggested by Nita Saini who herself has suffered from depression). We did not choose an intervention in which participants, for example, were given a personal trainer, as this would be very expensive and unlikely to be adopted widely by the NHS. Nor did we choose to use a traditional 12 session “exercise on prescription” scheme at the local sports centre as this does not seem to lead to a sustainable increase in physical activity levels.(2) Our study was a pragmatic trial designed to evaluate an intervention that could be used in addition to usual care in the NHS and allowed individuals choice and autonomy about their physical activity in order to lead to a more sustained change in behaviour.
The patients who took part in this trial were referred by their general practitioners as potentially suitable and had a diagnosis of depressive illness. The current NICE guidelines(3) make a recommendation for “structured” physical activity in mild and moderate depression (Pilling rapid response). However, we could find no evidence within our trial for increased effectiveness in those with less severe symptoms though our statistical power for this subgroup analysis was low. Many people, including participants in the trial,(4) express the opinion that physical activity can improve their mood, though this benefit might be shortlived and a randomised controlled study is giving an “average effect”. There could be subgroups of people who benefit and subgroups who do not – but at present we do not know if such subgroups exist and cannot identify them.
It is clear from much of the response both in the BMJ and the popular media that different commentators were interested in a range of questions, only one of which our study addressed. The “headline” that “exercise is no help for depression” clearly goes beyond our finding. We asked a pragmatic question concerning a feasible intervention that could be used in primary care. There are clearly some outstanding explanatory questions about the possible therapeutic role of physical activity in depression. Nevertheless, given the present state of knowledge, we think that people with depression should be recommended to have treatments such as antidepressants and cognitive behavioural therapy (3) that will on average help to relieve the depressive symptoms. Like all of us, people with depression should also be physically active and who knows – this may help some of the people some of the time.
1. Chalder M, Wiles NJ, Campbell J, Hollinghurst SP, Haase AM, Taylor AH, et al. Facilitated physical activity as a treatment for depressed adults: randomised controlled trial. BMJ. 2012;344:e2758. Epub 2012/06/08.
2. Pavey TG, Anokye N, Taylor AH, Trueman P, Moxham T, Fox KR, et al. Clinical effectiveness and cost-effectiveness of exercise referral schemes. Health Technology Assessment. 2011;15(44):1-254.
3. National Institute of Health and Clinical Excellence. Depression guideline (updated edition). London: The British Psychological Society and The Royal College of Psychiatrists, 2009.
4. Searle A, Calnan M, Lewis G, Campbell J, Taylor A, Turner K. Patients' views of physical activity as treatment for depression: a qualitative study. Br J Gen Pract. 2011;61(585):149-56.
Competing interests: No competing interests