Exercise and depression

Abstract

The prevalence of depression indicates it is one of the most common forms of mental illness. Depression can range from a well-managed mood disorder, to crippling and debilitating psychotic depression. Similarly, there are a range of exercises that may involve gentle movement through to high-intensity aerobic challenges. The evidence of the benefits of exercise in alleviating depression is uncertain and this chapter explores some of the current thinking and evidence around the mechanisms that cause depression and how various forms of exercise may alleviate symptoms. We touch upon the biological processes such as neuroinflammation, the effects of prolonged elevated cortisol levels, and the effects of genetics on depression. A longstanding belief about depression is the “serotonin hypothesis”, the way neurotransmitters affect our mood, concentration, and memory. It is important to have a holistic approach, considering the interaction of physical activity, psychological supports, our environment, current circumstances, and how this may change the outcome of mood. Sleep for example is a critical factor in how our body functions, so a regular bout of exercise often promotes good natural sleep without the need for sleeping pills. Medication, however, is often essential in the treatment of depression, so a combination of treatments that include exercise, cognitive therapies, and medication is an effective approach. The World Health Organization provides recommendations for weekly exercise, recently changing this for different age groups to a range rather than a fixed amount. When designing exercise programs, it is necessary to consider the audience and key factors that might influence the intervention outcomes. With depression, there are certain safety matters that should be considered, and we discuss how exercise can affect thoughts of self-harm and suicidal ideation. Exercise can benefit people with depression but there is more research required to define what is best practice.