Re: Facilitated physical activity as a treatment for depressed adults: randomised controlled trial
The study realized by Melanie Chalder et al1 suggested that advice and encouragement to increase physical activity is not an effective strategy for reducing symptoms of depression due to its lack of effectiveness as an adjunct treatment.
Although of high relevance, the study showed important limitations, since main parameters of physical training were not controlled. Several reviews, systematic reviews and meta-analysis articles have concluded that previous studies had showed several methodological limitations, such as lack of control of training parameters (e.g. intensity, frequency, and duration of exercise), diagnostic of depression, evaluation of remission and response to treatment, sample size and pharmacological treatment2-5 Unfortunately, the present study perpetuates several methodological flaws, especially in exercise prescription. One study published in 2005 showed that weekly energy expenditure is a determinant factor on efficacy of exercise on depression6. Depressive patients with energetic expenditure of 7 kcal/Kg/week showed lower response to treatment than patients with energetic expenditure of 17.5 kcal/kg/week. In addition, Singh et al7 verified that strength training of 80% 1MR (one maximum repetition) intensity promoted higher reduction of depressive symptoms than 20% 1MR. Obviously, there is a huge difference between advice to increase physical activity and supervised exercise with intensity and duration monitored.
To evaluate physical conditioning before starting a physical exercise program is important to determine exercise doses at the beginning and the dose-response to treatment. In the present study, physiological parameters were not used to determine this intensity. Moreover, energy expenditure evaluations might be not reliable if analyzed by questionnaires. Due to impossibility of using direct evaluation of energy expenditure, equations of American College of Sports and Medicine should have been used. Finally, it is important to comment that control group had practiced physical exercise before starting the experiment.
Previous clinical trials have already demonstrated that supervised exercise is effective on depressive treatment through control group with social contact, analysis of intention to treatment and comparisons among type, duration, and intensity of exercises. In addition, recent researches from our laboratory have showed better response and remission after exercise through subjective scales and cortical activity changes measured by electroencephalogram4 8.
Another potential influence in these findings was the evaluation of depressive symptoms by mail, since inadequate answers might have been chosen. The authors should have used both self-evaluations (e.g., BDI) and scales administered by health care professional (e.g., HRDS, MADRS). Finally, there is a wide range of age in the groups and the study has poor control criteria concerning to diagnostic exclusion. It means that the methodology is not reliable, since elderly patients and young adults, as well bipolar and psychotic patients can show different responses when exercise is included as an additional treatment.
In addition to clinical evidence, several studies have shown that physical exercise increases neurotrophic factors, neurogenesis, angiogenesis, synaptogenesis, mitochondrial biogenesis, neuroprotection, neuroplasticity, and reduce oxidative stress9. Thus, the conclusion of Chalder et al1 is, at least , polemic and questionable. Moreover, the message reproduced by media was mistaken, since the present study has not investigated the effect of physical exercise, but the effect of advice and encouragement to increase physical activity.
The above reviewed evidence illustrates the benefits of physical training on depression and methodological questions should be resolved in future randomized and controlled studies.
• Heitor Silveira
Center for Alzheimer’s disease and Related Disorders, Institute of Psychiatry, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.
Neuroscience Exercise Laboratory – LaNEx (PPGCEE/UGF), Rio de Janeiro, Brazil
• Helena Moraes
• Eduardo Matta Mello Portugal
• Andrea Deslandes (Corresponding Author)
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.
2. Stathopoulou G, Powers MB, Berry AC, A.J. J, Smits JA, Otto MW. Exercise Interventions for Mental Health: A Quantitative and Qualitative Review. Clinical Psychology: Science and Practice 2006;13(2):179-93.
3. Mead GE, Morley W, Campbell P, Greig CA, McMurdo M, Lawlor DA. Exercise for depression. Cochrane Database Syst Rev 2009(3):CD004366.
4. Deslandes AC, Moraes H, Alves H, Pompeu FA, Silveira H, Mouta R, et al. Effect of aerobic training on EEG alpha asymmetry and depressive symptoms in the elderly: a 1-year follow-up study. Braz J Med Biol Res 2010;43(6):585-92.
5. Krogh J, Nordentoft M, Sterne JA, Lawlor DA. The effect of exercise in clinically depressed adults: systematic review and meta-analysis of randomized controlled trials. J Clin Psychiatry 2011;72(4):529-38.
6. Dunn AL, Trivedi MH, Kampert JB, Clark CG, Chambliss HO. Exercise treatment for depression: efficacy and dose response. Am J Prev Med 2005;28(1):1-8.
7. Singh NA, Stavrinos TM, Scarbek Y, Galambos G, Liber C, Fiatarone Singh MA. A randomized controlled trial of high versus low intensity weight training versus general practitioner care for clinical depression in older adults. J Gerontol A Biol Sci Med Sci 2005;60(6):768-76.
8. Silveira H, Deslandes AC, de Moraes H, Mouta R, Ribeiro P, Piedade R, et al. Effects of exercise on electroencephalographic mean frequency in depressed elderly subjects. Neuropsychobiology 2010;61(3):141-7.
9. Dishman RK, Berthoud HR, Booth FW, Cotman CW, Edgerton VR, Fleshner MR, et al. Neurobiology of exercise. Obesity (Silver Spring) 2006;14(3):345-56.
Competing interests: No competing interests