Exercise: Effective “Medicine” for Depression

Regular exercise fights depression in so many ways! Approximately one-third of individuals who have major clinical depression do respond well to antidepressant medication. There is more hope though! Exercise is successful in reducing even treatment-resistant depression.¹ Even single bouts of exercise have favorable effects on the brain.² This blog explains how exercise fights depression.

 

Widespread Depression

The World Health Organization estimates more than 264 million people of all ages suffer from depression. Worldwide, depression is a leading cause of disability. Approximately 17% of the U.S. population will suffer from a major depressive episode at some point in their lifetime. It is the leading cause of disability in the United States.³

The Depressed Brain

Long-lasting major depression is a brain disease. Circuits of the brain malfunction so that the lower brain usurps the front brain. Consequently, fear and ruminations (negative thoughts focused on negative emotions) dominate. If depression continues, major areas in the brain will eventually atrophy. The electronics and the chemistry within the brain become imbalanced.

Exercise Optimizes the Front Brain

To defeat depression, one needs the optimization of executive functions and a healthy front brain. Why? The front brain (precisely, the prefrontal cortex) engages in such executive duties as initiating a task, self-control, planning, organizing, and the mental flexibility to switch from one task or idea to another. Working memory, which is the capacity to hold information in the mind for completing a task, is another executive function. Self-monitoring is the ability to measure one’s performance against some standard of what is needed or expected. It is the ability to accept and weigh feedback on one’s performance.

Researchers found that regular aerobic exercise improves executive functioning. Moreover, regular exercise is linked to the increased thickness of the brain’s outer layer in the left frontal area in both young and old individuals.⁴ The thickness of the cortex is an indication of how much atrophy is in that part of the front brain.

Exercise Rejuvenates the Brain!

Exercise training that produces changes in skeletal muscle can purge the blood of a substance that accumulates during stress and is harmful to the brain.⁵ Several studies show that brain inflammation is a major contributor to many cases of depression. Moderate exercise helps to reduce inflammation in depression.⁶

Synapses are microscopic points of communication between neurons. Exercise increases brain-derived neurotrophic factor that supports the growth of neurons and synaptic sprouting. Building good synaptic connections is essential in this process. Major depression shrinks the hippocampi, an organ in the temporal lobe that helps regulate mood, learning processes, and long-term memory. Even a short burst of physical activity directly boosts a specific gene’s activity that increases connections between neurons in the hippocampi.⁷

Want to Keep Your Marbles? Play!

Several studies suggest that sedentary living is linked to a greater risk of anxiety.⁸ Sedentary behavior is also associated with an increased risk of depressive symptoms in adolescents.⁹ What’s the good news? Any degree of regular physical activity of any intensity can help in reducing one’s risk for depression.

When compared to people who reported moderate to intense exercise, one study found that people who reported light to no exercise experienced a decline equal to 10 more years of aging in cognitive skills such as thinking and memory!¹⁰

Exercise Is a Natural Anti-Depressant

Appropriate regular exercise is quite useful for both preventing and treating depression. Indeed, for mild to moderate depression, exercise compared favorably to antidepressant medication. Some studies show that regular exercise for at least nine weeks is needed to achieve the desired effect.

A series of randomized controlled studies found that although antidepressants reduce the symptoms more quickly than just exercise, four months of exercise effectively treated major clinical depression as well as antidepressants would have. Interestingly, these studies showed that exercise significantly reduces the rates of reoccurring depression better, within ten months, than medication.¹¹

How to Exercise

Weight-lifting, as well as aerobic exercise, improves depression.¹² Physical activity may help fight depression in seniors by stimulating muscle-generated mood boosters.¹³

A meta-analysis examined the results of 33 randomized, controlled studies on depression and strength training of more than 2000 participants and discovered weight lifting improves depression symptoms. The researchers controlled for age, gender, or improvements in muscle mass.¹⁴

When to Exercise

Morning exercise is particularly useful in conquering depression. Morning exposure to sunlight increases serotonin, a neurotransmitter essential for a positive mood. Additionally, moderately intense physical activity in the morning improves decision-making and other executive functioning in older adults.¹⁵ Moreover, morning exercise enhances sleep quality and increases the length of time in deep restorative sleep.¹⁶

Where to Exercise

As much as possible, do exercise in green spaces, areas of grass, trees, or other vegetation. Even short bouts of exercise in green environments improve both self-esteem and mood.¹⁷ Children who grow up with greener surroundings have up to 55 percent less risk of developing various mental disorders later in life.¹⁸

Another study found that individuals who took a 90-min walk through a natural environment reported lower levels of rumination (repetitive thought focused on negative emotions) and showed reduced neural activity in an area of the brain linked to risk for mental illness compared with those who walked through an urban environment.¹⁹

Gardening Helps

There is robust evidence that suggest that gardening helps to reduce depression and anxiety symptoms, stress, and mood disturbance. Additionally, gardening increases in quality of life, sense of community, physical activity levels, and cognitive function.²⁰

Early studies suggest that bacteria found in the soil activated a group of neurons that produce the brain chemical serotonin that promotes positive outlook.²¹. Start small and don’t tackle more than you can handle. You want to keep your schedule as manageable as possible.

Altruistic, Useful Exercise

Useful work provides a sense of accomplishment. Doing kind acts encourages a warm glow in one’s soul. Using your exercise time to help others altruistically produces magnificent healing effects on the mind. Why? Acts of altruism, with no hope of personal benefit, activate the reward areas of the brain. They also activated the subgenual anterior cingulate cortex (ACC).²² This area in the front brain plays an important role in regulating decision-making, emotion, and impulse control. Degeneration in this ACC correlates with depressed mood.²³ Studies suggest that exercise training increases the gray matter in the ACC at least in adolescents with subclinical mood disorders.²⁴

Lifting boxes at a food bank or doing yard work for a needy neighbor—without remuneration—will often lift one’s mood. Of course, depression requires time to build up one’s health. Therefore, we would not encourage regular commitments beyond one’s strength, schedule, or resources.

Conclusions:

In the prevention and treatment of depression, exercise is an urgent priority! Careful thought is needed to motivate individuals with major depression disorder to include regular implementation of exercise into their program on a regular basis. Depression is multi-faceted. In its treatment, we need to address all contributors sufficiently.

 

1. Mota-Pereira J. Moderate exercise improves depression parameters in treatment-resistant patients with major depressive disorder. J Psychiatr Res. 2011; 45(8):1005–1011. pubmed.ncbi.nlm.nih.gov/21377690/↩
2. Schuch FB. Neurobiological effects of exercise on major depressive disorder: a systematic review. Neurosci Biobehav Rev. 2016; 61:1–11. pubmed.ncbi.nlm.nih.gov/26657969/↩
3. Craft LL. The Benefits of Exercise for the Clinically Depressed. Prim Care Companion J Clin Psychiatry. 2004; 6(3): 104–111. www.ncbi.nlm.nih.gov/pmc/articles/PMC474733/↩
4. Stern, Yaakov. Effect of aerobic exercise on cognition in younger adults A randomized clinical trial. Neurology, 2019 DOI: 10.1212/WNL.0000000000007003↩
5. Karolinska Institutet. “How physical exercise protects the brain from stress-induced depression.” ScienceDaily. ScienceDaily, 25 September 2014. www.sciencedaily.com/releases/2014/09/140925131345.htm↩
6. Paolucci, Emily & Loukov, Dessi & Bowdish, Dawn & Heisz, Jennifer. (2018). Exercise reduces depression and inflammation but intensity matters. Biological Psychology. 133. 10.1016/j.biopsycho.2018.01.015↩
7. Chatzi C Exercise-induced enhancement of synaptic function triggered by the inverse BAR protein, Mtss1L. eLife, 2019; 8↩
8. University College London. “Sitting still linked to increased risk of depression in adolescents.” ScienceDaily. ScienceDaily, 11 February 2020. www.sciencedaily.com/releases/2020/02/200211193051.htm↩
9. BioMed Central. “Increased anxiety associated with sitting down: Low-energy activities that involve sitting down are associated with an increased risk of anxiety.” ScienceDaily. ScienceDaily, 19 June 2015. www.sciencedaily.com/releases/2015/06/150619085534.htm↩
10. Willey J.Z. Leisure-time physical activity associates with cognitive decline: The Northern Manhattan Study. Neurology, 2016; DOI: 10.1212/WNL.0000000000002582↩
11. Blumenthal J. et al. Effects of exercise training on older patients with major depression. Arch Intern Med. 1999 159:2349–2356. pubmed.ncbi.nlm.nih.gov/10547175/↩
12. Craft LL. The Benefits of Exercise for the Clinically Depressed. Prim Care Companion J Clin Psychiatry. 2004; 6(3): 104–111. www.ncbi.nlm.nih.gov/pmc/articles/PMC474733/↩
13. McMaster University. “Working it out: Researchers find exercise may help fight depression in seniors.” ScienceDaily. ScienceDaily, 7 February 2019. www.sciencedaily.com/releases/2019/02/190207111309.htm↩
14. Gordon B. Association of Efficacy of Resistance Exercise Training With Depressive Symptoms.Meta-analysis and Meta-regression Analysis of Randomized Clinical Trials. JAMA Psychiatry June 18, Vasc jamanetwork.com/journals/jamapsychiatry/article-abstract/2680 ↩
15. Wheeler M. J. . Distinct effects of acute exercise and breaks in sitting on working memory and executive function in older adults: a three-arm, randomised cross-over trial to evaluate the effects of exercise with and without breaks in sitting on cognition. British Journal of Sports Medicine., 2019 DOI: 10.1136/bjsports-2018-100168↩
16. Fairbrothe K. Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives. Health Risk Manag. 2014; 10: 691–698. www.ncbi.nlm.nih.gov/pmc/articles/PMC4270305/↩
17. Barton, J., Pretty, J. (2010). What is the Best Dose of Nature and Green Exercise for Improving Mental Health? A Multi-Study Analysis. Environmental Science and Technology. 44: 3947-3955↩
18. Engemann K. Residential green space in childhood is associated with lower risk of psychiatric disorders from adolescence into adulthood. Proceedings of the National Academy of Sciences, 2019; 201807504 doi.org/10.1073/pnas.1807504116↩
19. Bratman GN. Nature experience reduces rumination and subgenual prefrontal cortex activation. June 29, 2015; doi.org/10.1073/pnas.1510459112↩
20. Soga M. Gardening is beneficial for health: A meta-analysis. Prev Med Rep. 2017 Mar; 5: 92–99↩
21. University of Bristol. “Getting Dirty May Lift Your Mood.” ScienceDaily. ScienceDaily, 10 April 2007. www.sciencedaily.com/releases/2007/04/070402102001.htm↩
22. University of Sussex. “The warm glow of kindness is real, even when there’s nothing in it for you.” ScienceDaily. ScienceDaily, 27 September 2018. www.sciencedaily.com/releases/2018/09/180927105720.htm↩
23. Rudebeck P. A role for primate subgenual cingulate cortex in sustaining autonomic arousal. PNAS April 8, 2014 111 (14) 5391-5396; first published March 24, 2014. doi.org/10.1073/pnas.1317695111↩
24. Kangguang Lin. Aerobic exercise impacts the anterior cingulate cortex in adolescents with subthreshold mood syndromes: a randomized controlled trial study. Transl Psychiatry. 2020; 10: 155. www.ncbi.nlm.nih.gov/pmc/articles/PMC7235232/↩