Felipe B. Schuch and Brendon Stubbs
Depression is a leading cause of global burden affecting people across all ages, genders, and socioeconomic groups. Antidepressants are the cornerstone of treatment, yet treatment response is often inadequate. While some psychological interventions such as cognitive behavioral therapy can also help alleviate depressive symptoms, alternative and complimentary treatment options are required. In particular, therapeutic interventions that also address the greatly increased levels of obesity and cardiovascular disease among people with depression may offer added value. With the rising burden of premature mortality due to cardiovascular disease in people with depression and promising evidence base for physical activity to improve depressive symptoms, it is important to review the role, benefits, and underlying neurobiological responses of exercise among people with depression.
There has been a growing body of evidence to suggest that higher levels of physical activity reduce a person’s risk of incident depression. It appears that lower levels of cardiorespiratory fitness increase an individual risk of depression, suggesting that physical activity and physical fitness have a key role in the prevention of depression. Moreover, exercise can improve depressive symptoms in those with subthreshold depressive symptoms and major depressive disorder. Despite the effectiveness of exercise, the optimal dose and frequency are yet to be fully elucidated. Nonetheless, exercise appears to be well accepted by people with depression, with relatively low levels of dropout from interventions, particularly when supervised by qualified professionals with expertise in exercise prescription. Various barriers to engaging in exercise exist and motivational strategies are essential to initiate and maintain exercise. A number of hypotheses have been postulated to determine the antidepressant effect of exercise; however, most are based on animal models or models elucidated from people without depression. Therefore, future representative research is required to elucidate the neurobiological antidepressant response from exercise in people with depression. Physical activity interventions targeting fitness should be a central part of the prevention and management of depression. In particular, physical activity interventions offer a viable option to prevent and address cardiometabolic abnormalities and cardiovascular disease, which account for a significant amount of premature deaths in this population and are not addressed by standard pharmacological and psychological therapies.