Re: Facilitated physical activity as a treatment for depressed adults: randomised controlled trial
Regarding the TREAD (TREAtment of Depression with physical activity) study (1) in which the authors somewhat unexpectedly found negative results on a facilitated physical activity in patients with depression, the following issues should be seriously taken into account before getting to premature recommendation against exercise in this patient population in general. First of all, the severity of depression in this sample may not be generalisable to many patients with this chronic and frequently recurrent clinical condition. The study originally planned to recruit those with depression (as assessed with the International Classification of Diseases, 10th edition) not taking antidepressants or (presumably) taking them for less than eight consecutive weeks at the longest. Further, the study excluded those who had failed to respond previously to antidepressants.
Considering that antidepressants are seriously considered (or indeed frequently indicated) for those with moderate or severe depression and quite a few patients in the real-world actually fail to respond to a single antidepressant trial (2), the results pertain solely to milder forms of the illness for which nonspecific effects are not negligible (that may be exemplified as a well-known placebo effect in a drug comparative study). Further, while a goal of 1000 or more metabolic equivalent of task minutes per week might be too difficult to achieve for those with more severe illness who would have problematic fatigue and loss of goal-directed activities in the first place (note that the study originally aimed to the intensity of physical activity that is recommended for healthy adults), the percentage of those who were active beyond this threshold improved from 28% from baseline to 40-49% at follow-up periods in usual care group, suggesting a nonspecific effect that argues against any differentials between the two groups. Likewise, the use of antidepressants declined from 53 % at four months to 42% at 12 months in this group, which contrasts further from 59% to 35% in intervention group, respectively. While the dose of antidepressants is another problem, those with marked symptoms are unlikely to discontinue from antidepressant treatment within this timeline, again pointing to milder form of the illness.
Moreover, while this study utilized the Beck Depression Inventory (BDI) as the primary outcome measure, a lack of objective measures of depression is a limitation as well as assessments for subjective perspectives other than depression (as assessed with the BDI that gives us a clue on an aspect of the severity (3)) such as quality-of-life, well-being and self-esteem, or those for social functioning. Possible discrepancy of subjective versus objective evaluations is well possible (medicated in part by personality traits), and subjective improvements in mood may well translate into improvements in other subjective domains, or could ideally functioning in the end, the elements of which are all critically relevant for successful treatment of depression.
These issues taken together as well as a relatively large effect implied from a systematic review on this topic (4), the claim 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” appears too definitive to argue against a room of exercise in patients with depression. Especially, a potential role of adjunctive, facilitated but realistic physical activity in patients with moderate to severe depression being treated with antidepressants without substantial relief (who may be relatively more resistant to nonspecific effects of an intervention) needs to be further evaluated.
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. doi: 10.1136/bmj.e2758.
2. Warden D, Rush AJ, Trivedi MH, Fava M, Wisniewski SR. The STAR*D Project results: a comprehensive review of findings. Curr Psychiatry Rep. 2007;9(6):449-59.
3. Uher R, Farmer A, Maier W, Rietschel M, Hauser J, Marusic A, et al. Measuring depression: comparison and integration of three scales in the GENDEP study. Psychol Med. 2008;38(2):289-300.
4. Mead GE, Morley W, Campbell P, Greig CA, McMurdo M, Lawlor DA. Exercise for depression. Cochrane Database Syst Rev. 2009;(3):CD004366.
Competing interests: No competing interests