Exercise: Physical Activity for Mental Health

Sponsored by the ACOFP Foundation, with winners selected by the ACOFP Health & Wellness Committee, the Namey/Burnett Preventive Medicine Writing Award honors the memory of Joseph J. Namey, DO, FACOFP, and John H. Burnett, DO, FACOFP—dedicated advocates for osteopathic medicine—and recognizes the best preventive medicine blog posts submitted by osteopathic family medicine students and residents.

The word “exercise” is typically associated with topics such as weight loss, physical fitness, heart health, and, for many, being a chore. It is typically part of the routine that has to be done in order for us to be able to enjoy whatever dessert it is we have our eye on or a box that we feel the need to check off of our to-do lists. We tend to associate exercise with physical health, and it is often something we do for our physical bodies. Yes, exercise does benefit the body’s physical health in numerous ways, but it also has the power to affect mental health. As osteopathic physicians, we look at patients as individuals and take into account more than just vital signs and lab values. We are advocates of lifestyle modifications and non-pharmacologic treatments to supplement our medical management in order to enhance the quality of life of our patients rather than putting a temporary bandaid over a singular problem. Exercise is one such supplement. Patients are more than just physical bodies, so we will explore how exercise can benefit not only the body but the mind and spirit as well, particularly as it relates to depression.

Depression is characterized in the DSM-IV to include symptoms of depressed mood, loss of interest, weight changes, sleep changes, psychomotor changes, lack of energy, feelings of guilt, difficulty concentrating, and thoughts of death, including suicidal ideation.¹ The effects of depression not only impact a person’s mental health, but these effects can carry over and lead to negative consequences in a patient’s work life, personal life, and physical health.² Millions of people are affected by depression; it can be debilitating and is a significant contributor to disability.^3,4

Treatment of depression typically includes pharmacologic therapy in addition to cognitive behavioral therapy or interpersonal therapy.^5,6 Two fifths of patients are reported to have suboptimal responses to these therapies as well as adverse effects from pharmacotherapy.⁶ Schmitter et al. suggest that exercise may be used as monotherapy or supplemental therapy to traditional management.⁶ In addition to improvements in depressive symptoms, exercise is also affordable and widely available, making it a viable addition to a patient’s current management.⁶

Exercise is a broad term referring to any type of physical activity. It has documented benefits to physical health including weight loss, improvement in cardiovascular health, diabetes and metabolic syndrome risk reduction, cancer risk reduction, and improvements in bone health.⁷ In addition to physical benefits, it has been suggested that exercise can be preventive of depressive episodes.⁸ A systematic review by Hu et al. concluded that exercise can also reduce symptoms of depression.⁹ The means by which exercise affects depression have been widely studied, and there are many theories and proposed mechanisms aiming to understand how the two are connected.

One suggested process by which exercise affects depression is the idea that exercise can enhance nerve cell growth.¹⁰ Micheli et al. state that increased neurogenesis is likely correlated with a decrease in depressive symptoms, and neurogenesis was shown to be stimulated by antidepressant medications and running.⁴ Gujral et al. describe neural pathways affected by exercise, specifically volume enhancement in the prefrontal cortex and hippocampus, which are also affected by antidepressants, suggesting that exercise-induced effects in these areas have similar antidepressant effects to those of antidepressant medications.³ Exercise has also been shown to increase levels of brain-derived neurotropic factor (BDNF), which plays a role in neurogenesis and neuron survival.^3,11,12  It has also been suggested that white matter integrity may be reduced in depression, and exercise may contribute to enhancements in white matter connectivity.³

Another contribution made by exercise is its effect on hormone levels. It is hypothesized that disruption of the hypothalamic-pituitary-axis plays a role in depression.¹³ One of the main manifestations of this is high cortisol levels.¹³ Hidalgo suggests that exercise results in decreased cortisol levels as well as increases in endorphins, thus leading to elevations in mood and subsequent attenuations in depressive symptoms.¹⁰ Zhao et al. discuss the ability of exercise to increase levels of 5-HT and norepinephrine in addition to decreasing cortisol levels, leading to reductions in depressive symptoms.¹¹

Though exercise and depression have been studied and connected, there is not an exact prescription for the amount of time one should be exercising nor which type of exercise yields the most positive results. Pearce et al. found that walking for about 2.5 hours in a week correlated with a 25% reduction in depression risk.⁸ They also discovered that addition of exercise to a routine consisting of no physical activity resulted in the most significant benefits.⁸ Zhao et al. discuss the anti-depressive effects of aerobic exercise and resistance training, however, they note that resistance training has been less studied.¹¹ Zhao et al. also consider mind-body exercises, such as yoga, and their effects on depression reduction.¹¹ Based on these studies, it seems that it does not matter how a patient decides to get moving; it only matters that they do.

There are many ways to get active and get the body and mind moving. If you are looking for something simple and affordable to offer to your patients, they can take a walk around their neighborhood or find a scenic trail in the area. Walking also provides a great opportunity to meditate and connect with nature. If a patient is looking to incorporate resistance training into their routine, perhaps they would enjoy Crossfit. Any interest in self defense? Taekwondo and boxing are great options. There are endless possibilities when it comes to exercise, and there is something for everybody. No matter what a patient chooses to do, they will be moving their body and mind in the right direction simply by moving.

Regardless of a patient’s physical or mental health status, it can be concluded that exercise is a prescription that would have numerous benefits to the body, mind, and spirit both as a preventive measure and an adjunct to other therapies. As osteopathic physicians, we have a unique opportunity to provide patients with ways to improve their quality of life. When it comes to prevention and treatment of depression, exercise is one tool to keep in our arsenals.

References

1. O’Connor, E. A., Whitlock, E. P., Gaynes, B., & Beil, T. L. (2010). Screening for depression in adults and older adults in primary care: an updated systematic review.
2. Depression and Its Effect on Your Life. Resources To Recover. https://www.rtor.org/2020/03/18/depression-and-its-effect-on-your-life/.
3. Gujral, S., Aizenstein, H., Reynolds III, C. F., Butters, M. A., & Erickson, K. I. (2017). Exercise effects on depression: Possible neural mechanisms. General hospital psychiatry, 49, 2-10.
4. Micheli, L., Ceccarelli, M., D’Andrea, G., & Tirone, F. (2018). Depression and adult neurogenesis: positive effects of the antidepressant fluoxetine and of physical exercise. Brain research bulletin, 143, 181-193.
5. Philippot, A., Dubois, V., Lambrechts, K., Grogna, D., Robert, A., Jonckheer, U., ... & De Volder, A. G. (2022). Impact of physical exercise on depression and anxiety in adolescent inpatients: A randomized controlled trial. Journal of affective disorders, 301, 145-153.
6. Schmitter, M., Spijker, J., Smit, F., Tendolkar, I., Derksen, A. M., Oostelbos, P., ... & Vrijsen, J. N. (2020). Exercise enhances: study protocol of a randomized controlled trial on aerobic exercise as depression treatment augmentation. BMC psychiatry, 20(1), 1-11.
7. Benefits of Physical Activity. Centers for Disease Control and Prevention. https://www.cdc.gov/physicalactivity/basics/pa-health/index.htm.
8. Pearce, M., Garcia, L., Abbas, A., Strain, T., Schuch, F. B., Golubic, R., ... & Woodcock, J. (2022). Association Between Physical Activity and Risk of Depression: A Systematic Review and Meta-analysis. JAMA psychiatry.
9. Hu, M. X., Turner, D., Generaal, E., Bos, D., Ikram, M. K., Ikram, M. A., ... & Penninx, B. W. (2020). Exercise interventions for the prevention of depression: a systematic review of meta-analyses. BMC public health, 20(1), 1-11.
10. López-Torres Hidalgo, J. (2019). Effectiveness of physical exercise in the treatment of depression in older adults as an alternative to antidepressant drugs in primary care. BMC psychiatry, 19(1), 1-7.
11. Zhao, J. L., Jiang, W. T., Wang, X., Cai, Z. D., Liu, Z. H., & Liu, G. R. (2020). Exercise, brain plasticity, and depression. CNS Neuroscience & Therapeutics, 26(9), 885-895.
12. Bathina, S., & Das, U. N. (2015). Brain-derived neurotrophic factor and its clinical implications. Archives of Medical Science, 11(6), 1164-1178.
13. Keller, J., Gomez, R., Williams, G., Lembke, A., Lazzeroni, L., Murphy, G. M., & Schatzberg, A. F. (2017). HPA axis in major depression: cortisol, clinical symptomatology and genetic variation predict cognition. Molecular psychiatry, 22(4), 527-536.