Exercise As A New Treatment For Depression

A walk a day keeps the doctor away. Nothing in life is this simple, but research has uncovered a possible alternative treatment and prevention for depression—exercise. From gardening to running, physical activity has demonstrated positive effects on people with depression. Although the scientific evidence regarding such studies is inconclusive, researchers have found many benefits of utilizing exercise in the treatment of depression.

How Exercise Stops Depression In It's Tracks

Depression is an illness that affects mood and behavior. Although no one knows for certain why people become depressed, one culprit may be the way neurotransmitters (chemical messengers) function in the brain. Physical activity also affects the manner of which neurotransmitters work. Exercise changes hormone levels in the following ways:

1. Serotonin: Physical activity aids in the absorption of serotonin. This factor is important for people suffering from depression as serotonin production and reception may be the cause of depression in some people.

2. Epinephrine and Norepinephrine: Exercise enhances the activities of epinephrine and norepinephrine. Epinephrine and norepinephrine are two neurotransmitters that work in tandem as part of the “flight or fight” response. Norepinephrine is produced from dopamine, and low levels of norepinephrine may cause depression. Even more remarkable is that when people exercise regularly, the two chemicals operate more efficiently while people are in a relaxed state.

3. Brain Cell Growth: The chemical effects of physical fitness result in neurogenesis, the growth of brain cells. In the same way, it may prevent the decay of cells in the hippocampus, a region of the brain involved with memory. Depression causes the death of cells in this region, and re-growth may alter “the circuit of nerve activity that keeps people stuck in depressive thoughts and feelings,” according to Maia Szalavitz, a neuroscience journalist at Time.

4. Cortisol: Cortisol is known as “the stress hormone”, because the body secretes more of it during our “fight or flight” response. People who live in a constant state of stress or have difficulties coping with stress may produce more cortisol than is healthy. Chronic stress and prolonged elevated cortisol levels may lead to a number of negative effects on the body, which may lead to depression. Exercise may reduce cortisol activity, which is the same effect that psychotropic drugs have.

More Than Just One Factor

Cortisol is also involved in many other body functions, which could put people at risk for depression. When the adrenal glands secrete cortisol, it helps the body to regulate gluclose, blood pressure, insulin, immunity, and inflammation. Since depression often occurs in the presence of other diseases (comorbidity), many complications involved with the secretion of cortisol can lead to depression. Comorbid depression can exist in patients with diabetes, cancers, obesity, and many other diseases. 

For example, many illnesses cause inflammation in the body, and when the immune system is fighting an illness, the body responds with anti- or pro-inflammatory cytokines (messengers of the immune system). Researchers have discovered that people with depression have elevated levels of pro-inflammatory cytokine. Could cortisol stabilization lead to a better-regulated immune and inflammatory response? It is possible that this factor could be a benefit of exercise, but more research is needed to find the link between cortisol secretion, exercise, diseases, and depression.

Exercise:  A Powerful Stress Combatant

What is known is that exercise provides a variety of other benefits to help relieve stress and symptoms of depression. It provokes the release of endorphins, neurotransmitters that provide positive feelings for the brain and body. By releasing anxieties and stress through exercise, people choose to work through their difficulties in a healthy way, rather than resorting to physical injury or substance use. Regular physical fitness can help improve a person’s health, which can boost self-esteem, improve sleeping habits, and distract from negative emotions. Physical activity can improve cardiovascular and respiratory health, as well as maintain a healthy weight. By improving and preventing most physical conditions, people decrease their risks of living with depression. Additionally, people who exercise may have valuable opportunities to socialize with others. Whether working out at a gym or walking around the neighborhood, each trip out can increase your connect with others, leading to necessary human contact.

Preventing Depression

Being physically active may prevent the onset of depression for many people. A review in the American Journal of Preventative Medicine analyzed 26 years of research to conclude that low levels of exercise may help prevent depression. The review indicates that 20 to 30 minutes of daily, moderate physical activity can keep people, in all age groups, physically and mentally well. While researchers cannot recommend a specific regimen for physical activity, the evidence is clear: Regular exercise is inexpensive and can provide numerous, sustainable benefits for people suffering from depression.

 - Melissa Lavery, M.S.

References

Greenblatt, J. (2011, November 23). The Brain on Fire: Inflammation and Depression. Retrieved January 14, 2015, from http://www.psychologytoday.com/blog/the-breakthrough-depression-solution/201111/the-brain-fire-inflammation-and-depression

Schuster, S. (2011, March 24). Norepinephrine Vs. Epinephrine. Retrieved January 15, 2015, from http://www.livestrong.com/article/226152-norepinephrine-vs-epinephrine/

Stannard, L. (2011, May 5). The Effects of Serotonin and Norepinephrine in Depression. Retrieved January 15, 2015, from http://www.livestrong.com/article/73224-effects-serotonin-norepinephrine-depression/

Stress management. (2012, July 21). Retrieved January 15, 2015, from http://www.mayoclinic.org/healthy-living/stress-management/in-depth/exercise-and-stress/art-20044469

Szalavitz, M. (2013, March 20). It’s All in the Nerves: How to Really Treat Depression | TIME.com. Retrieved January 15, 2015, from http://healthland.time.com/2013/03/20/its-all-in-the-nerves-how-to-really-treat-depression/

University of Bern. (2014, September 16). Sport, physical activity help against depression. ScienceDaily. Retrieved January 15, 2015 from www.sciencedaily.com/releases/2014/09/140916084825.htm

University of Toronto. (2013, October 28). Moderate exercise not only treats, but prevents depression. ScienceDaily. Retrieved January 15, 2015 from www.sciencedaily.com/releases/2013/10/131028163003.htm

Wiley. (2013, September 11). Exercise provides some benefits for depression. ScienceDaily. Retrieved January 15, 2015 from www.sciencedaily.com/releases/2013/09/130911211921.htm