This morning, the BBC News site reported on a study into exercise and depression written up in the British Medical Journal. “Exercise ‘no help for depression’” is how the BBC summed up the study. Immediately, Twitter went wild, with countless sufferers of mental health conditions chipping in to say that they were a firm fan of exercise as a means of coping with their problems.
But what was the study really measuring, and what can it tell us? The full title is “Facilitated physical activity as a treatment for depressed adults: randomised controlled trial.” The first thing to notice about the study is that it only drew participants from primary care – the people studied were all seeking treatment for depressive symptoms from their GP. So straight away, anyone who was being treated for depressive symptoms by a psychiatrist (most likely to be the people with major, rather than mild or moderate depression, or depression as part of a personality disorder, bipolar or schizophrenia) were ruled out. Participants were randomly assigned to either an “intervention” group, or a group who received the standard GP treatment for depression. Members of both groups completed a self-rating depression scale at the start of the study. The intervention group were then given access to up to three face to face sessions and 10 telephone calls with “a trained physical activity facilitator” over a period eight months. Both groups completed the depression scale again four months into the intervention.
So what was in this intervention package? The physical activity facilitators used motivational interviewing (a frequently used tool to help individuals to become ready for behavioural change) amongst other tools to encourage participants to take up “locally available opportunities”. This coaching approach focused on helping people build realistic activity levels into their lifestyle, in the hope that this would prove sustainable in the longer term. The aim was to get each participant to undertake moderate-vigorous activity for a total of 150 minutes a week, “but if that seemed unrealistic then the facilitator encouraged any increase in physical activity, whatever the intensity.”
The overall outcome of the study – which is what the BBC seized on – was that no significant difference was between the two groups when they completed the depression scale 4 months into the study, nor at further follow up points at 8 and 12 months. The research team acknowledged there were weaknesses to the study, particularly the fact that “physical activity is notoriously difficult to measure and the self reported assessment could have been biased by knowledge of the treatment allocation. The effect of the intervention on physical activity outcomes must therefore be treated with some caution.” This means that participants could have consciously or unconsciously have over-reported their engagement in physical activity because they knew they were in the group whose exercise was being monitored. The study team felt that this was unlikely to be a major problem, however, as the participants’ exercise diaries closely mirrored the data they obtained from the electronic accelerometers the study participants wore to record their activity.
So what does this study really tell us? That the particular intervention – face to face and telephone coaching to encourage people to use what facilities are available to them locally – did not make any noticeable difference to the participants’ level of depression in comparison with people with similar symptoms who did not receive the intervention. The intervention was specifically designed to be something that could be easily carried out in primary care, in other words it was designed to meet the needs/limitations of treating depression in primary care. It was not designed around what people with depression or in a specific local area thought might be helpful.
The phrase “locally available opportunities” is interesting, because even though the sample was recruited through “GP practices in Bristol and Exeter”, participants’ opportunities are unlikely to have been the same. Even activities such as going for a walk will be much more difficult if you live in an estate with few safe open spaces, than if you live adjacent to a welcoming. Accessing local swimming pools and council-run fitness suites will be easier if they are close to a bus route. Joining groups is much easier if you have disposable income to spend on a zumba or yoga classes, than if you are on benefits. Likewise there is no qualitative data available on participants’ attitude towards exercise prior to the intervention. People who are more naturally sporty are more likely to see exercise as a useful strategy than those who have hated exercise since school PE and wouldn’t be seen dead in a gym.
So maybe this study just wasn’t measuring the right things, or offering the right intervention. I certainly don’t think we should chuck exercise on the scrapheap just yet. But, equally, let’s not become uncritical about its benefits either. There seemed to be a bit of evangelising going on this morning, and I am sometimes concerned that those who do find exercise beneficial make assumptions about its efficacy and appropriateness across the board. We need to be wary, for example, of the following myths:
1) Anyone can do a little bit of exercise. While exercise seems highly likely to help with conditions such as mild-moderate anxiety and depression, anyone who is in a really severe, deep depression is likely to have genuine difficulties getting out of bed, washing, dressing, etc. They are not being lazy, they are suffering from “psychomotor retardation”, a well known effect of severe depression which can make people move, speak or even think more slowly. Exercise proponents may mean well, but encouraging someone in this state to exercise will feel as impossible as asking them to flap their arms and fly to the moon. We also need to consider that many people have other illnesses or disabilities in addition to mental health problems. Suggestions like “anyone can run in the park for free” wrongly assume that we are all equally physically able.
2) Exercise will stop you from relapsing. Exercise may help you keep well. But if you relapse, it’s highly unlikely to be simply because you stopped swimming twice a week! Recovery and relapse are complex and multi-faceted, and it’s simply not possible to be sure of a causal link between exercise and continued wellness.
3) If you exercise, you won’t need medication/therapy. For some people that’s true, but again they are likely to be the people towards the milder end of the clinical spectrum. If some people can tackle their depression or anxiety through exercise, without needing drugs, great! But no-one should feel that they “should” be able to run the blues away. For people with longer-term and harder to treat conditions such as bipolar, schizophrenia or personality disorders, exercise may be one tool that people use to pursue recovery or maintain wellness in periods of remission, but that’s going to be it – one tool from a kit of many, with more traditional tools such as drugs or therapy likely to be at the forefront.
4) Exercise is always good for mental health problems. Usually, maybe; always? Definitely not. For example, I know that I am far from the only bipolar person who over-exercises in a high, sometimes to the point that I injure myself. If I am feeling a little elated, I can naughtily develop my hypomania, by undertaking repetitive exercise. Running is especially powerful, particularly if I listen to fast music on headphones as I run. There is a lot of counting involved in many forms of exercise – reps, lengths, laps – which can feed into obsessive traits, and over-exercising can be an integral part of eating disorders.
So let’s celebrate when we find exercise helpful! Whether you believe today’s reports, or have faith in previous studies recommending exercise for mental distress, what ultimately matters is whether it works for you. And if you are depressed but exercise is beyond you right now, please don’t feel guilty. We can only do what we can do.