by Johanna Popp
Stressed lately? Low in energy? Too exhausted to meet up with friends after a long workday? These feelings could indicate early signs of declining mental health. According to the World Health Organization, mental health is defined as emotional, psychological, and social well-being that influences behavior, mood, and thoughts. The month of May is Mental Health Awareness Month, which focuses on raising awareness of mental health issues, fighting against stigma, and providing support for affected individuals and their families. This campaign is important because the destigmatization of mental illness increases the likelihood of public discussions of prevention and treatment options, making it easier for people to prioritize their mental health.
Failure to prioritize one’s mental well-being could lead to the development of mental health conditions, including prevalent disorders such as depression and anxiety. The onset of symptoms is often due to a combination of an already existing genetic, psychological, or biological vulnerability, paired with stress from life experiences. Reducing stressors, especially for people who are predisposed to mental illness, is crucial to protect mental health. Even though this is established knowledge, one out of five adults is currently struggling with a mental illness, which equates to over 50 million Americans! However, almost a third of affected individuals are not able to receive the treatment they need, often due to financial reasons. As of now, medications including antidepressants, anti-anxiety medications, and antipsychotics are still commonly used as frontline treatment. Although effective in many cases, they are often times very expensive and can bring about harmful side effects including upset stomach, headache, or weight gain (Solmi et al., 2020). Certain types of anti-anxiety medications, such as benzodiazepines, also bear a risk of abuse and substance dependance (Janhsen et al., 2015). Thus, it is crucial to identify safe treatment and prevention strategies that can improve and counteract the development of mental health disorders in a cost-effective way.
… being physically active is somehow related to a lower risk of developing mental health disorders.
One effective and low-cost alternative for managing mental health is exercise. As Hippocrates once said, “Walking is a man’s best medicine” (Batman, 2012). Going for a walk, participating in a yoga class, or lifting weights at the gym are all activities that provide mental health benefits. There is plenty of scientific evidence that performing any physical activity, whether casually vacuuming the house, or exercising in a more structured physical activity like lifting weights, is associated with a lower risk of developing a mental illness, including depression and anxiety (Arent et al., 2020; Dasso, 2019; Schuch et al., 2018). For example, an analysis of 49 studies demonstrated that people with higher self-reported physical activity or exercise levels show a lower risk of developing depression, even after controlling for age, sex, geographic region, and medical history (Schuch et al., 2018). Likewise, another analysis of 13 studies reported that higher levels of self-reported physical activity, again regardless of the type, are associated with a reduced likelihood of developing anxiety disorders (Schuch et al., 2019). Additionally, a unique and extensive study observing almost 400k individuals for a duration of 21 years, showed that cross-country skiing was linked to a lower risk of developing anxiety (Svensson et al., 2021). Taken together, these studies suggest that being physically active is somehow related to a lower risk of developing mental health disorders. To show that physical activity can be an effective prevention and treatment strategy, intervention studies must be considered.
Importantly, exercise is being studied as an effective treatment option and a way to boost treatment efficacy. Surprisingly, this benefit is seen with a variety of different exercises types. As one would expect, it has been shown that strenuous exercise can improve depressive symptoms. For example, 30 minutes of moderate-intensity treadmill exercise can improve vigor and psychological well-being in patients with major depressive disorder (Bartholomew et al., 2005). Similarly, weightlifting may be effective for reducing worry symptoms in patients with generalized anxiety disorder (Herring et al., 2012). However, less strenuous forms of exercise, such as yoga, can also exert positive effects on mental health. One study showed that a six-week yoga intervention, on top of the medical or psychotherapeutic treatment that patients were already receiving, reduced depressive symptoms in individuals relative to another group solely undergoing regular treatment (de Manincor et al., 2016). Another study in college students with a diagnosed mental health disorder demonstrated that an eight-week yoga intervention significantly reduced depressive, anxiety, and stress symptoms (Falsafi, 2016). Hence, a variety of exercise types can be valuable tools in protecting and improving mental health.
The benefits of exercise on mental health are thought to occur through biochemical and psychological mechanisms (Mikkelsen et al., 2017). Biochemical mechanisms are related to the release of neurochemicals (neurotransmitters and neuromodulators), and stress hormones. A key player mediating the positive influence of exercise on mental health is a chemical known as brain-derived neurotrophic factor (BDNF), a certain kind of neuromodulator. Exercise increases the release of BDNF, which in turn encourages the growth of new neurons, especially in the hippocampus. The hippocampus and other structures of the limbic system (e.g., the amygdala and the hypothalamus) are involved in managing autonomic or endocrine function in response to emotional stimuli (e.g., the ‘fight or flight response’), and have been reported to be smaller in people with depression and anxiety (Holmes, 2022; Nolan et al., 2020; Schindler et al., 2012; Schmaal et al., 2016; Terlevic et al., 2013).
Physical activity can also release important neurotransmitters associated with the pleasure and reward system (e.g., dopamine), an individual’s state of alertness (e.g., norepinephrine), or anxiety levels (e.g., serotonin; Matta Mello Portugal et al., 2013). Furthermore, exercising can trigger the release of other neurochemicals, such as opioids or endocannabinoids, which promote a sense of euphoria and well-being (Dietrich & McDaniel, 2004; Matta Mello Portugal et al., 2013). Lastly, being physically active can lower cortisol levels and thus, reduce stress (Matta Mello Portugal et al., 2013). Despite the current knowledge of the effects of exercise on the body, the interactions are very complex and there is a lot that remains to be understood. For example, it is still an open question of how these mechanisms interact with one another, and how these interactions could inform treatment options (Smith & Merwin, 2021).
… the mental ‘time out’ during a workout could be responsible for some beneficial effects of exercise.
Exercise can also promote mental health through psychological mechanisms. Individuals who exercise get better at tolerating discomfort, they learn new coping strategies, and they also develop a sense of mastery, self-efficacy, and confidence through exercise-related successes (Holmes, 2022, Smith & Merwin, 2021). Interestingly, the distraction from negative thoughts, ruminations, or stressful life events that is achieved through exercise also seems to be a key factor. According to the ‘distraction hypothesis’, the mental ‘time out’ during a workout could be responsible for some beneficial effects of exercise (Mikkelsen et al., 2017). However, recognizing that there are various biochemical and psychological mechanisms underlying the positive impacts of exercise, opens up even more questions: How do the biochemical and psychological effects interact? Are there synergystic or additive effects on processes influencing mental health outcomes? Clearly, our understanding of these mechanisms is still in its infancy.
All in all, exercise is known to be a valuable tool in the prevention and treatment of mental health disorders. However, there is still much to learn about the effects of distinct exercise types and underlying biochemical and psychological mechanisms. Conducting further research in this area is essential, as it will ultimately help to uncover individualized protective strategies that could significantly contribute to overall quality of life.
Written by Johanna Popp
Illustrated by Mary Bullock
Edited by Mary Bullock, Gabrielle Sarlo, Lauren Wagner
Arent, S. M., Walker, A. J., & Arent, M. A. (2020). The Effects of Exercise on Anxiety and Depression. In Handbook of Sport Psychology (S. 872–890). John Wiley & Sons, Ltd. https://doi.org/10.1002/9781119568124.ch42
Bartholomew, J. B., Morrison, D., & Ciccolo, J. T. (2005). Effects of acute exercise on mood and well-being in patients with major depressive disorder. Medicine and Science in Sports and Exercise, 37(12), 2032–2037. https://doi.org/10.1249/01.mss.0000178101.78322.dd
Batman, D. C. (2012). Hippocrates: „Walking is man’s best medicine!“ Occupational Medicine, 62(5), 320–322. https://doi.org/10.1093/occmed/kqs084
Dasso, N. A. (2019). How is exercise different from physical activity? A concept analysis. Nursing Forum, 54(1), 45–52. https://doi.org/10.1111/nuf.12296
de Manincor, M., Bensoussan, A., Smith, C. A., Barr, K., Schweickle, M., Donoghoe, L.-L., Bourchier, S., & Fahey, P. (2016). Individual yoga for reducing depression and anxiety, and improving well-being: A randomized controlled trial. Depression and Anxiety, 33(9), 816–828. https://doi.org/10.1002/da.22502
Dietrich, A., & McDaniel, W. F. (2004). Endocannabinoids and exercise. British Journal of Sports Medicine, 38(5), 536–541. https://doi.org/10.1136/bjsm.2004.011718
Falsafi, N. (2016). A Randomized Controlled Trial of Mindfulness Versus Yoga: Effects on Depression and/or Anxiety in College Students. Journal of the American Psychiatric Nurses Association, 22(6), 483–497. https://doi.org/10.1177/1078390316663307
Herring, M. P., Jacob, M. L., Suveg, C., Dishman, R. K., & O’Connor, P. J. (2012). Feasibility of exercise training for the short-term treatment of generalized anxiety disorder: A randomized controlled trial. Psychotherapy and Psychosomatics, 81(1), 21–28. https://doi.org/10.1159/000327898
Holmes, B. (2022). Exercise boosts the brain—And mental health. Knowable Magazine | Annual Reviews. https://doi.org/10.1146/knowable-012122-1
Janhsen, K., Roser, P., & Hoffmann, K. (2015). The Problems of Long-Term Treatment With Benzodiazepines and Related Substances. Deutsches Ärzteblatt International, 112(1–2), 1–7. https://doi.org/10.3238/arztebl.2015.0001
Matta Mello Portugal, E., Cevada, T., Monteiro-Junior, R., Guimarães, T. T., Rubini, E., Lattari, E., Blois, C., & Deslandes, A. (2013). Neuroscience of Exercise: From Neurobiology Mechanisms to Mental Health. Neuropsychobiology, 68, 1–14. https://doi.org/10.1159/000350946
Mikkelsen, K., Stojanovska, L., Polenakovic, M., Bosevski, M., & Apostolopoulos, V. (2017). Exercise and mental health. Maturitas, 106, 48–56. https://doi.org/10.1016/j.maturitas.2017.09.003
Nolan, M., Roman, E., Nasa, A., Levins, K. J., O’Hanlon, E., O’Keane, V., & Willian Roddy, D. (2020). Hippocampal and Amygdalar Volume Changes in Major Depressive Disorder: A Targeted Review and Focus on Stress. Chronic Stress, 4, 2470547020944553. https://doi.org/10.1177/2470547020944553
Schindler, S., Geyer, S., Strauß, M., Anwander, A., Hegerl, U., Turner, R., & Schönknecht, P. (2012). Structural studies of the hypothalamus and its nuclei in mood disorders. Psychiatry Research: Neuroimaging, 201(1), 1–9. https://doi.org/10.1016/j.pscychresns.2011.06.005
Schmaal, L., Veltman, D. J., van Erp, T. G. M., Sämann, P. G., Frodl, T., Jahanshad, N., Loehrer, E., Tiemeier, H., Hofman, A., Niessen, W. J., Vernooij, M. W., Ikram, M. A., Wittfeld, K., Grabe, H. J., Block, A., Hegenscheid, K., Völzke, H., Hoehn, D., Czisch, M., … Hibar, D. P. (2016). Subcortical brain alterations in major depressive disorder: Findings from the ENIGMA Major Depressive Disorder working group. Molecular Psychiatry, 21(6), 806–812. https://doi.org/10.1038/mp.2015.69
Schuch, F. B., Stubbs, B., Meyer, J., Heissel, A., Zech, P., Vancampfort, D., Rosenbaum, S., Deenik, J., Firth, J., Ward, P. B., Carvalho, A. F., & Hiles, S. A. (2019). Physical activity protects from incident anxiety: A meta-analysis of prospective cohort studies. Depression and Anxiety, 36(9), 846–858. https://doi.org/10.1002/da.22915
Schuch, F. B., Vancampfort, D., Firth, J., Rosenbaum, S., Ward, P. B., Silva, E. S., Hallgren, M., Ponce De Leon, A., Dunn, A. L., Deslandes, A. C., Fleck, M. P., Carvalho, A. F., & Stubbs, B. (2018). Physical Activity and Incident Depression: A Meta-Analysis of Prospective Cohort Studies. The American Journal of Psychiatry, 175(7), 631–648. https://doi.org/10.1176/appi.ajp.2018.17111194
Smith, P. J., & Merwin, R. M. (2021). The Role of Exercise in Management of Mental Health Disorders: An Integrative Review. Annual review of medicine, 72, 45–62. https://doi.org/10.1146/annurev-med-060619-022943
Solmi, M., Fornaro, M., Ostinelli, E. G., Zangani, C., Croatto, G., Monaco, F., Krinitski, D., Fusar-Poli, P., & Correll, C. U. (2020). Safety of 80 antidepressants, antipsychotics, anti-attention-deficit/hyperactivity medications and mood stabilizers in children and adolescents with psychiatric disorders: A large scale systematic meta-review of 78 adverse effects. World Psychiatry, 19(2), 214–232. https://doi.org/10.1002/wps.20765
Svensson, M., Brundin, L., Erhardt, S., Hållmarker, U., James, S., & Deierborg, T. (2021). Physical Activity Is Associated With Lower Long-Term Incidence of Anxiety in a Population-Based, Large-Scale Study. Frontiers in Psychiatry, 12. https://www.frontiersin.org/articles/10.3389/fpsyt.2021.714014
Terlevic, R., Isola, M., Ragogna, M., Meduri, M., Canalaz, F., Perini, L., Rambaldelli, G., Travan, L., Crivellato, E., Tognin, S., Como, G., Zuiani, C., Bazzocchi, M., Balestrieri, M., & Brambilla, P. (2013). Decreased hypothalamus volumes in generalized anxiety disorder but not in panic disorder. Journal of Affective Disorders, 146(3), 390–394. https://doi.org/10.1016/j.jad.2012.09.024