Re: Facilitated physical activity as a treatment for depressed adults: randomised controlled trial
Depression has a relapsing course which has not been considered in the study design.
The Treatment of Depression with physical activity (TREAD) study is quite large and well designed. The results of the study got wide media coverage with the main message for the public to the effect that "Exercise Doesn't Treat Depression". This is quite unfortunate in my opinion since there are several aspects that have not been considered in the study design.
Depression is a common condition in Primary Care that typically has a relapsing course. This is important for General Practitioners since they see their patients over an extended period of time. It is equally important to them to cure a current episode as it is to prevent the possible next episode of depression. Effective interventions targeting relapse have the potential to dramatically reduce the point prevalence of the condition.
In this context one might consider the case of Mindfulness Based Cognitive Therapy (MBCT) which has shown to be effective in the relapse prevention of depression in patients who had more than two previous episodes. MBCT which contains components of physical activity is however ineffective during active episodes of depression.
This suggests the following considerations with regard to the present study. Firstly "patients were only eligible to be included in the study if they had a current diagnosis of ICD-10 depressive episode F32". That implies that all patients in the free interval of their recurring condition were excluded from the study. Secondly, the authors state that they "excluded those who had failed to respond previously to antidepressants". That probably means that many severe cases have been excluded.
To conclude the present study shows the ineffectiveness of physical activity in mild cases of depressive episodes while the effectiveness of physical activity for the relapse prevention in severe cases of depression remains an open question and a field for further research. A hasty generalisation that physical activity is ineffective for all cases of depression remains problematic.
1 Chalder M, Wiles NJ, Campbell J, et al. Facilitated physical activity as a treatment for depressed adults: randomised controlled trial. Bmj 2012;344:e2758–e2758.
2 Teasdale JD, Segal ZV, Williams JMG, et al. Prevention of relapse/recurrence in major depression by mindfulness-based cognitive therapy. Journal of Consulting and Clinical Psychology 2000;68:615–23.
3 Piet J, Hougaard E. The effect of mindfulness-based cognitive therapy for prevention of relapse in recurrent major depressive disorder: a systematic review and meta-analysis. Clinical psychology review 2011;31:1032–40.
Competing interests: No competing interests