Summary: A recent study indicates that exercise alleviates depression by enhancing motivation through reduced inflammation and improved dopamine function. This insight could pave the way for personalized exercise programs as a treatment option.
The review emphasizes the role of aerobic exercise in addressing anhedonia and low energy associated with depression. Large-scale trials are necessary to further validate this hypothesis and identify obstacles to exercise.
Key Facts:
- Exercise reduces inflammation and enhances dopamine, boosting motivation.
- Aerobic exercise effectively addresses symptoms like anhedonia and low energy.
- Personalized exercise programs could emerge as a new treatment strategy for depression.
UCL researchers have investigated the brain and body processes through which physical exercise alleviates depressive symptoms.
Depression, the leading cause of disability worldwide, disrupts various brain and psychological functions, including learning and memory. While physical activity, particularly aerobic exercise, has been shown to reduce depressive symptoms, the underlying mechanisms have remained unclear.
In a new review article published in Translational Psychiatry, researchers propose a novel hypothesis to explain the antidepressant effects of exercise. They suggest that the key factor may be motivation, which is crucial for alleviating several symptoms of depression, such as anhedonia (a lack of interest or pleasure in life), low energy, and ‘brain fog’.
The team reviewed research papers on the mechanisms of depression in both humans and animals, concluding that depression, particularly anhedonia, is linked to elevated inflammation caused by the body’s immune response. This inflammation is also associated with disrupted dopamine transmission. These biological changes may be key factors leading to decreased motivation and a reduced willingness to exert physical or mental effort.
Conversely, exercise reduces inflammation, enhances dopamine function, and boosts motivation. The researchers believe this could be a significant reason why exercise has an antidepressant effect.
Lead author Dr. Emily Hird (UCL Institute of Cognitive Neuroscience) stated: “The antidepressant effect of aerobic exercise has been convincingly demonstrated through randomized controlled trials, but its mechanism is not well understood. This is partly because it likely involves various biological and psychological processes.
“For instance, in addition to its positive effects on inflammation, dopamine, and reward processing, exercise also reduces oxidative stress and improves self-esteem and self-efficacy.
“However, we propose that exercise—particularly aerobic activities that make you sweaty and out of breath—decreases inflammation and boosts dopamine transmission, which in turn increases the desire to exert effort, thereby enhancing overall motivation.”
The team hopes that understanding how exercise alleviates depressive symptoms will guide the development of new treatment strategies, such as personalized exercise programs.
Dr. Hird stated: “Understanding the mechanisms behind the antidepressant effects of physical activity in depression could also enhance our knowledge of the causes of depression and lead to novel intervention strategies, particularly personalized interventions and social prescribing.”
To further test their hypothesis, the researchers recommend conducting large randomized controlled trials to assess the antidepressant effects of exercise, while also measuring variables such as inflammation, dopamine transmission, and motivation.
Investigating potential barriers to exercise is also crucial.
Dr. Hird added: “Addressing barriers to exercise—especially in people with depression—is essential, as regular physical activity may alleviate symptoms, improve mood, and empower individuals on their path to recovery. Finding strategies to encourage exercise is key.”
The team is currently conducting a trial based on the hypothesis proposed in the review, involving 250 participants aged 18 to 60, funded by a Wellcome Mental Health Award.