Exercise and Depression - A Cautious Approach
Last week, the British Medical Journal published results of a research trial suggesting that, contrary to NICE guidelines and current research trends, the addition of facilitated exercise doesn’t improve the symptoms of depression compared with usual care alone.
Unfortunately, many newspapers tried to simplify and sensationalize this message, with headlines such as “Exercise does not lift depression” and “Exercise is not effective in treating depression”. Yet the trial concluded that the addition of a programme of exercise promotion and guidance to standard treatments for depression does not produce better results than standard treatment alone; and this is an important distinction to make.
The research was undertaken by the University of Exeter, University of Bristol and the Peninsula College of Medicine and Dentistry Research with the aim of investigating 'the effectiveness of facilitated physical activity as an adjunctive treatment for adults with depression presenting in primary care'. Note the wording here. The emphasis of the study is not on the effectiveness of exercise on depression but rather the effectiveness of facilitating physical activity as a treatment for depression. Any conclusions therefore need to be based on this premise.
The study looked at 361 adults who had recently been diagnosed with depression after visiting their GP. The participants were randomised into two groups: one group was offered the standard care for depression, while the other group was offered the standard care as well support from a trained physical activity facilitator over eight months. Groups were then followed up for 12 months to assess any change in their symptoms. The study concluded that adding facilitated exercise to a standard care programme failed to alleviate symptoms of depression more than standard care alone.
However, there are certain parts of the study that need to be taken into account when considering this conclusion. The most obvious point is that the research is almost entirely based on self-reporting. The intervention group was merely offered advice and guidance from a trained physical activity facilitator which they were free to take or leave; participants were not actually seen exercising and their levels of exercise were entirely self-reported. In other words, there was no objective measure of exercise; no minimum intensity of exercise or specified activities were required. This could have affected the reliability of the results. It would have perhaps been more prudent to have participants undertake structured and monitored exercise, and build on types of exercise that have been shown to be effective in alleviating depressive symptoms (e.g. aerobic exercise).
There is also the problem that the comparator group was free to exercise for the duration of the study. Indeed, the study clearly states that the non-intervention group were offered the 'usual treatment' for depression which along with talking therapies and antidepressants also included 'referral to “exercise on prescription” schemes'. So essentially, both groups were offered exercise as a treatment, it's just that one group was offered it more proactively. Therefore the project only really evaluated how effective extra guidance or encouragement to exercise is. In addition, both groups were free to access any treatment usually available in primary care; these did not seem to be taken into account in the analysis (apart from medication).
The problematic nature of this study is encapsulated in the recommendation at the end of the paper which states that "clinicians and policy makers should alert people with depression that advice to increase physical activity will not increase their chances of recovery from depression". The inference is that advice alone to increase physical activity will not increase chances of recovery. This seems rather self-evident; after all, advice to take medication is no substitution to actually taking the medication.
So does this study ultimately go against current NICE guidance? The simple answer is no, not really. NICE has itself stated that “for patients with depression, in particular those with mild or moderate depressive disorder, structured and supervised exercise can be an effective intervention that has a clinically significant impact on depressive symptoms". The exercise undertaken by the participants in this recent study cannot be characterised as structured or supervised and so ultimately this guidance has not been challenged.
However, it does suggest that it is important to see more research in this area, to give us a better idea of the relationship between physical exercise and its impact on the symptoms of depression, compared with standard care alone. This would require rigorous selection and measurement of the exercise that people are actually doing, in the same way that dosage levels of medication should be carefully tested. There is a plethora of evidence to suggest that exercise can improve people’s overall mental health and even help alleviate the symptoms of common mental health disorders, such as depression and anxiety, and this shouldn’t be ignored.
Physical activity is good for your mental health in general – it causes the release of endorphins and other ‘natural feel good chemicals’ that improve your mood and make you feel happier. Exercise can also do more than help with your overall health; it can be a great way to meet people, socialise, and can give you some time away from the hustle and bustle of daily life. Leading an active lifestyle can provide something worthwhile in your life; something that you really enjoy, that gives you a goal to aim for and a sense of purpose. It can alleviate tension, stress and mental fatigue, give you a natural energy boost, improve your quality of sleep, and even reduce feelings of anger and frustration."