Using Exercise to Defeat Depression

Types of Exercise that can help Relieve Depression

Depression is a complex mental illness, yet something as simple as exercise can help to relieve it. However, not jall types of exercise can help. In particular, aerobic exercises which increase heart rate and breathing seem to be the most effective. This can include walking, running, swimming, golfing, and many other similar forms of exercise.

However, in a meta-analysis by Blumenthal and Ong examining this relationship of how exercise helps depression, the authors only conclude that exercise is conclusively effective for helping mild depression. It is also unclear what is an appropriate amount of exercise to relieve depression symptoms. However, exercise is an excellent supplement to psychotherapy and other treatments for depression. It should also be noted that exercise needs to be continued to maintain its antidepressant effects. Still, it is unclear why exercise has such an effect, but there are some theories which try to explain it.

Why does Exercise improve Depression Symptoms?

There are many theories which try to explain this relationship, and three will be discussed here. Two are similar and physical in nature while the third is psychological.

The first theory states that exercise causes the brain to increase levels of neurotransmitters such as serotonin and norepinephrine. This is known as the monoamine hypothesis. While it is still unclear how this happens, animal studies have found increased rates of these neurotransmitters after exercise. This is also similar to how antidepressant medications work, but this process may be related to the second theory.

This second theory states that exercise leads to the release of a protein called brain derived neurotropic factor (BDNF). After exercise, increased amounts of BDNF has been shown to be released in rats. BDNF has also been shown to be released when these rates are given antidepressants. Likewise, when exercise and antidepressants has been paired in rats, they show a decrease in depressive symptoms within two days instead of two weeks. Finally, an increased release of BDNF is associated with an equally increasing amount of serotonin providing stronger evidence that BDNF may be responsible for the antidepressant effects of exercise.

The final theory states that exercise helps depression psychologically. Specifically, it is believed that exercise increases a depressed person's self-efficacy to handle stress and anxiety, a lower perceived vulnerability to threat, and increased cognitive control. While this hasn't been demonstrated with a general feeling of self-efficacy, a coping self-efficacy has been found to increase with exercise. This theory is known as the self-efficacy hypothesis which states that self-efficacy arises from the learning of a new health related skill, and this skill is used to meet goals. This begins to combat the feelings of worthlessness and hopelessness associated with depression which leads to improved mental health.

In conclusion, the research to support these theories are limited with the BDNF hypothesis having the most support, but exercise can help to fight mild depression and is a welcome addition to depression treatments.

References

Blumenthal J. A. & Ong, L. (2009). A Commentary on Exercise and Depression: And the Verdict Is… Mental Health and Physical Activity, 2(2), 97-99.

Craft, L. L. Proposed Mechanisms Underlying the Exercise and Depression Relationship: Relevance to Drug Abuse. Retrieved from https://www.seiservices.com/nida/1014032/Final%20Presentations/NIDA%20PA%20June%205/Craft.pdf on May 21, 2011.

McGovern, M. K. (2002). The Effects of Exercise on the Brain. Retrieved from https://serendip.brynmawr.edu/bb/neuro/ neuro05/web2/mmcgovern.html on May 21, 2011.