Erin Bahry, BKin Student, Rakhbeer Boparai, BSc Kin Student, Taylor Dechaine, BKin Student,
Madi Gillespie, BKin Student, and Ariana Purificati-Fune, BSc Kin Student
Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta
Take home message
• The research findings are inconclusive as to whether exercise results in decreased depressive symptoms for individuals with multiple sclerosis (MS).
• Previous research studies on exercise interventions in individuals with MS have often overlooked depression as a primary outcome, which has limited the power in many of the identified studies.
• Recent studies have placed a greater emphasis on depressive symptoms as a primary outcome, which may help explain the trend toward positive findings.
• Many patients with MS experience depressive disorders, which are compounded by other symptoms of the disease including fatigue, weakness and discoordination (Patten et al., 2017).
• Exercise has the potential to decrease depressive symptoms in the general population (Cooney et al., 2013), however, there is no conclusion as to whether the same is true in individuals with MS.
How the study was done
• The authors updated the systematic review completed by Dalgas et al. (2015), which assessed the effects of exercise on depressive symptoms in individuals with MS.
• The authors searched three databases, retrieving studies published after 16 October 2013, and extracted the relevant information from all studies that met the inclusion criteria: i) must be a randomized controlled trial (RCT); ii) must evaluate an exercise intervention compared with either non-training controls, active controls, or another exercise intervention; iii) must include a primary validated measure of depressive symptoms of depression or an instrument with a clearly defined depression subscale; and iv) must be available in English.
• All of the studies indicate that a definite diagnosis of MS was present for research participants, and an Expanded Disability Status Scale (EDSS) level was provided for each participant.
• Eleven new studies were included in the updated systematic review to assess the effects of exercise on depressive symptoms in patients with MS. A qualitative synthesis of the data was performed. A meta-analysis was not included.
What the researchers found
• In the original systematic review, only four of fifteen studies showed positive effects of exercise interventions on depressive symptoms, while the updated systematic review showed positive effects of exercise interventions on depressive symptoms in eight of eleven studies.
• Overall, twelve of the twenty-six total RCTs analyzed showed positive changes in depressive symptoms in individuals with MS, with the rest showing no difference or inconclusive results.
• The original systematic review was limited in that most studies did not report depressive symptoms as a primary outcome of their exercise intervention, often rendering them statistically underpowered. Updated research has shifted towards a greater emphasis on depressive symptoms being a primary outcome, and may be implicated in the greater number of positive findings.
• In both the original and updated systematic review, a reduction in depressive symptoms was correlated with a reduction in perceptual fatigue.
• There is no evidence that exercise may be detrimental to depressive symptoms in patients with MS.
• As only twelve of twenty-six studies showed positive results of exercise on depressive symptoms, there cannot be a conclusive decision on whether exercise does improve depressive symptoms in individuals with MS.
• However, more recent research shows the potential for exercise to have positive effects on depression, as there is a shift towards a more profound emphasis on depressive symptoms as a primary outcome, with sufficiently powered study designs.
Cooney, G.M., Dwan K., Greig, C.A., Lawlor, D.A., Rimer, J., Waugh, F.R., McMurdo, M., & Mead, G.E. (2013). Exercise for depression. Cochrane Database of Systematic Reviews 9. https://doi.org/10.1002/14651858.CD004366.pub6.
Dalgas, U., Stenager, E., & Sloth, M. (2015). The effect of exercise on depressive symptoms in multiple sclerosis based on a meta-analysis and critical review of the literature. European Journal of Neurology, 22(3), 443. https://doi-org/10.1111/ene.12576
Patten, S.B., Marrie, R.A., & Carta, M.G. (2017). Depression in multiple sclerosis. International Review of Psychiatry, 5(29), 463-472. https://doi.org/10.1080/09540261.2017.1322555.