June 9, 2012
Exercise and Depression – A Tale of Misreporting and A Ray of Hope
Except that it showed no such thing, and the authors acknowledge this openly in the conclusions of their paper.
(Martin Robbins traces the Chinese Whispers succinctly at the Guardian.)
So What Was That Study About?
Many people report that exercise helps them keep the black dog of depression under control. If your depression is so severe that you can’t even get out of bed, exercise coaching does not make much sense, but for people who can still be active, exercise might work.
How do you implement exercise programmes? Do you shackle each participant to a treadmill for thirty minutes a day? Not if you would like people to take up regular exercise for the rest of their lives. What you do instead is provide advice and coaching. There’s an old saying: “If you want to feed a person for a day, give them a fish. If you want to feed them for the rest of their lives, teach them to fish.” This is how the intervention was designed.
What keeps people from exercising? What motivates them to get out and get active? What kind of exercise can people best fit into their own lives? The TREAD coaching programme covered all of this and more. People who went through TREAD coaching were able to work out a plan that allowed them to be more active. Roughly half the people in the study received TREAD coaching in addition to their usual care (i.e., antidepressants, counselling, or other exercise programmes, if available), the other half received usual care.
Did TREAD increase activity levels? It did – even after controlling for antidepressant use, baseline physical activity levels, and depression severity. No matter how bad participants were initially, they got more active, and the increase in activity often lasted for a year after treatment had finished. That’s impressive.
Did this increase in activity help with depression? Not really; any change in levels was small. After four and twelve months, people in the usual care group and people who got TREAD coaching got slowly better at a similar rate. The main measure was the Beck Depression Inventory, which goes from 0 to 63. Scores were 16.1 for the TREAD group versus 16.9 for the usual care group at four months, and 13.0 vs 13.5 at twelve months. A score from 0 to 13 is considered minimal, scores from 14 to 19 point to mild depression.
That could be a fluke due to a badly designed study, right?
How Good is the Study?
The study itself is sound – there’s no doubt about that. The physical activity coaching programme was carefully designed to incorporate effective strategies for changing people’s habits. It was brief and combined self-help elements with one-to-one coaching, which would have made it easy to implement within the NHS. People were followed up for much longer than usual (a year instead of four months). The statistical analysis is sound. TREAD worked very well in getting people to be more active.
For a more detailed, accessible evaluation of the study, see the summary prepared by the ever brilliant NHS Choices
So, Does That Mean Exercise Doesn’t Work?
Well, first of all, we are talking about physical activity – whatever that may mean for people. As the researchers found, definitions can vary greatly, from getting out of bed to running. Most physical activity was self-reported, because objective measures of how active people are in their daily lives are very difficult to get. The variety of activities people engaged in is actually a strength of this study, because different types of exercise are suited for different people. What’s more,
in the qualitative study, many participants talked about the way in which activity helped them. Again, it varies a lot. For some, it distracts from negative thoughts, for others, it builds self-esteem. The researchers also looked in detail at what physical activity means to people, and explored their experiences of TREAD in an interview study. Some people chose walking, others started rock climbing. Some took up gardening, others mention running.
Why didn’t exercise “work” then? There are several possible explanations. One is that it may only work for a certain type of person who can obtain mental benefits from the activity they have chosen. The other is the dose – maybe people need more intense activity more often. Finally, it’s worth emphasising again that TREAD was designed to promote physical activity per se, not regular sport or vigorous exercise that provides a good aerobic or anaerobic work out. People’s definitions of physical activity vary, and TREAD was designed to persuade people to be more active – whatever that might mean for them.
Don’t Forget – TREAD Itself Works!
In all the excitement about the lack of effect on depression, don’t forget one fantastic finding that is bound to be overlooked in the hoo-haa about the exercise and depression misreporting – TREAD works. People became more active, and they remained more active after one year. In addition, if there’s anything that will work systematically in the health system, it will be a coaching intervention like TREAD, because there is no one size fits all, everybody needs to find out for themselves what works for them.
So, if you’re a GP and want your patients to move more, look at the TREAD material; and if you have depression and would like to try and get more active, have a look, as well. It’s all in this lengthy report – the manual is at the end, but I would also recommend reading the report of the interview study.
The Limits of the RCT Paradigm
The study has raised the ire of many of us with depression who use exercise effectively (we think) to regulate our moods. But maybe it’s not physical activity as such that helps. Rather, activities such as walking, running, rock climbing or weightlifting might be embedded in a whole self-care package of things that work for us. What’s more, in order to exercise regularly, you need to prioritise it, which means that you need to care about yourself and your health. What if the key is to do not just any old activity, but to systematically train one or two activities that reliably shut down your racing thoughts and calm you down?
So let’s step away from the systematic reviews and formal trials for a moment. Let’s go back to the qualitative data, to the interviews and anecdotes, the observations and self-reports, and figure out where exercise sits within self-care, how often people who say exercise helps them are active, and what exactly it is that they do. In short, let’s revisit our hypotheses and look again.
An Anecdote (or Case Study)
I’ve had low moods for most of my life. I was diagnosed with depression at age 35. I was 37 when I discovered the right exercise prescription (weightlifting) and the right dose (2-4 times a week for at least an hour). Weightlifting works for me because
- it is an activity I can do – my gross motor dyspraxia prevents me from playing team sports, because any team that contains me will lose.
- it prevents me from ruminating, which means that the weight room becomes a safe space. This is something that no other physical activity can achieve.
- I can draw on gaining physical strength to replenish mental strength
- body image, something I have a major problem with, is not something lifters emphasise. What matters is how much you can lift, and the way you look will be a function of how and where you put on muscle.
- if you take lifting seriously, i.e. if you train, you also change other aspects of your life – you make sure to get enough rest and adequate nutrition, so that the musculoskeletal system can respond to the stimulus and grow strength.
Chalder, M., Wiles, N., Campbell, J., Hollinghurst, S., Haase, A., Taylor, A., Fox, K., Costelloe, C., Searle, A., Baxter, H., Winder, R., Wright, C., Turner, K., Calnan, M., Lawlor, D., Peters, T., Sharp, D., Montgomery, A., & Lewis, G. (2012). Facilitated physical activity as a treatment for depressed adults: randomised controlled trial BMJ, 344 (jun06 1) DOI: 10.1136/bmj.e2758