Exercise as a therapeutic modality for the prevention and treatment of depression

Abstract

While maintaining an active lifestyle and engaging in regular exercise are known to promote cardiovascular (CV) health, increasing evidence has emerged to indicate that these lifestyle behaviors also can promote psychological health and well-being. This has led to research to determine if exercise can serve as a potential therapeutic modality for major depressive disorder (MDD), which is a leading cause of mental-health impairment and overall disability worldwide. The strongest evidence to support this use comes from an increasing number of randomized clinical trials (RCTs) that have compared exercise to usual care, placebo controls, or established therapies in healthy adults and in various clinical populations. The relatively large number of RCTs has led to numerous reviews and meta-analyses, which generally have been concordant in indicating that exercise ameliorates depressive symptoms, improves self-esteem, and enhances various aspects of quality of life. Together, these data indicate that exercise should be considered as a therapeutic modality for improving CV health and psychological well-being. The emerging evidence also has led to a new proposed subspecialty of "lifestyle psychiatry", which promotes the use of exercise as an adjunctive treatment for patients with MDD. Indeed, some medical organizations have now endorsed lifestyle-based approaches as foundational aspects of depression management, with adoption of exercise as a treatment option for MDD. This review summarizes research in the area and provides practical suggestions for the use of exercise in clinical practice.

Keywords: Cardiac rehabilitation; Cardiovascular disease; Depression; Exercise; Lifestyle medicine.

Fig. 1.

Physical health and psychosocial risk factors for disease.

Fig. 2.

Results of meta-analysis of 25 randomized controlled trials of exercise interventions versus control conditions among individuals with major depressive disorder or depressive symptoms, indicating a large treatment effect. (Reprinted with permission from Schuch et al.).

Fig. 3.

Hamilton-D (HAM—D) scores for depression among 101 cardiac patients with elevated depression symptoms, randomized to three groups, after completion of their randomized treatments. The exercise group had the lowest depression scores. (Reprinted with permission from Blumenthal et al.).

Fig. 4.

Cardiac rehabilitation is based on the promotion of exercise training and the inclusion of four other core components, including stress management and psychotherapy (e.g., interpersonal therapy or cognitive behavior therapy) specifically for patients with depression when indicated.

Fig. 5.

Biological and psychosocial mechanisms that may contribute to the anti-depressant effects of exercise, along with examples of moderators and cofounding factors that may influence the study of these mechanistic relationships. (Reprinted with permission from Kendola et al.).

Fig. 6.

Association between physical activity level and risk for depression, from meta-analysis of 119,130 participants in 15 studies. An inverse curvilinear relationship between dose of physical activity and depression is noted, with the greatest reduction occurring at low levels of physical activity. (Reproduced with permission from Pearce et al.).