The effect of exercise on depression: a comprehensive review and meta-analysis of randomised controlled studies

Major depressive illness is a primary cause of disability globally, lowering life satisfaction more than debt, divorce, and diabetes. It also exacerbates comorbidities such as heart disease, anxiety, and cancer.Many individuals with major depressive illness are resistant to treatment, despite the fact that medication therapies and psychotherapy can be effective (5,67).8 Further more, many persons with depression have limited access to treatment, with only 51% coverage in high-income nations and 20% in low and lower-middle-income countries. 9 More evidence-based treatments are consequently required..

Exercise may be a useful supplement or alternative to medications and psychotherapy.1011121314 Exercise improves not only mental health but also a variety of physical and cognitive outcomes.151617 Clinical practice guidelines in the United States, United Kingdom, and Australia encourage physical activity as part of depression treatment. 18192021 However, these guidelines do not make clear, consistent recommendations about dose or exercise mode. British guidelines recommend group exercise programmes to increase physical activity, while the American Psychiatric Association recommends aerobic or resistance training. Australian and New Zealand guidelines recommend a combination of strength and vigorous aerobic exercises at least twice or three times per week.19

Guideline authors may struggle to make consistent recommendations based on existing mostly paired meta-analyses, which test a specific modality versus a specific comparator in a distinct group of individuals. 121322 These meta-analyses have been scrutinised for pooling disparate treatments and comparisons, resulting in confusing effect estimates.Some reviews exclude exercise treatments like yoga, tai chi, and qigong due to concerns about their compatibility with strength training.Many reviews have attempted to address this issue by integrating pairwise meta-analyses of specific treatments (23). A recent similar review discovered no differences across workout modes.13 Comparing Effect sizes between different pairwise meta-analyses might also be confused due to changes in analytical procedures used between meta-analyses, such as the selection of a control to serve as the reference. Network meta-analyses offer a more accurate technique to measure differences between interventions since they model both direct and indirect comparisons.24