Comparative effectiveness of three exercise types to treat clinical depression in older adults: A systematic review and network meta-analysis of randomised controlled trials

Background: Few studies have directly compared the effects of different exercise therapies on clinical depression in older adults. Thus, we conducted a systematic review and network meta-analysis of current evidence from randomised controlled trials (RCTs) to compare the effectiveness of three major exercise types (aerobic, resistance, and mind-body exercise) in clinically depressed older adults.

Methods: We followed PRISMA-NMA guidelines and searched databases for eligible RCTs (inception - September 12^th, 2019). RCTs were eligible if they included clinically depressed adults aged >65 years, implemented one or more exercise therapy arms using aerobic, resistance, or mind-body exercise, and assessed depressive symptoms at baseline and follow-up using a validated clinical questionnaire.

Results: A network meta-analysis was performed on 15 eligible RCTs comprising 596 participants (321 treatment and 275 controls), including aerobic (n = 6), resistance (n = 5), and mind-body (n = 4) exercise trials. Compared with controls, mind-body exercise showed the largest improvement on depressive symptoms (g = -0.87 to -1.38), followed by aerobic exercise (g = -0.51 to -1.02), and resistance exercise (g = -0.41 to -0.92). Notably, there were no statistically significant differences between exercise types: aerobic versus resistance (g = -0.10, PrI = -2.23, 2.03), mind-body versus aerobic (g = -0.36, PrI = -2.69, 1.97), or mind-body versus resistance (g = -0.46, PrI = -2.75, 1.83).

Conclusions: These findings should guide optimal exercise prescription for allied health professionals and stakeholders in clinical geriatrics. Notably, clinically depressed older adults may be encouraged to self-select their preferred exercise type in order to achieve therapeutic benefit on symptoms of depression. In coalition with high levels of compliance, these data provide encouraging evidence for the antidepressant effect of either aerobic, resistance, or mind-body exercise as effective treatment adjucts for older adults presenting with clinical depression.