Quick Note – The following is academic based and discusses different studies that have been done to investigate the impact exercise can have on depression. If you’re somebody who wants the proof, then continue reading. If you’re somebody who will fall asleep after reading 101 words I have summarized this in 100 words or less at the bottom.
Depression is one of the most common and possibly disabling mental illnesses in the world right now. Currently, depression affects at least one in five people across their lifetime (2012) and that number is only on the rise. The World Health Organization currently predicts that by 2020 depression will rank 2nd in global disease burden, only behind ischaemic heart disease. Depression is characterized by feelings of prolonged sadness, hopelessness, helplessness and irritability. It can lead to difficulty sleeping or concentrating along with decreased energy, weight changes, increased anxiety and even suicidal thoughts in severe cases. Unfortunately, due to all the physiological and psychosocial factors that can impact this illness, the exact cause of depression is currently unknown. It is usually referred to as a chemical imbalance in the brain due to the reduced production of certain neurotransmitters, but this can vary from person to person. Depression impacts everybody in different ways depending on how they are able to respond to, and cope with stress.
Current treatments for depression are based on using medications to “fix” this chemical imbalance in the brain. These antidepressants work by raising levels of three neurotransmitters that are associated with happiness: serotonin, dopamine and norepinephrine. Older antidepressants such as monoamine oxidase inhibitors (MAOIs) worked by blocking the enzyme monoamine oxidase which was involved in breaking down these neurotransmitters in the brain. By blocking this enzyme more serotonin, dopamine and norepinephrine is available which helps to fix the chemical imbalance that has been found to be associated with depression (2015). However, this drug is currently used as more of a last resort medication as it has a long list of potentially lethal side effects due to the way it interacts with certain foods and medications (some of these include fatigue, sexual dysfunction, weight gain, headache, fever, hypotension, irregular heartbeat, internal bleeding, seizure and stroke). The current most prescribed antidepressants are selective serotonin reuptake inhibitors (SSRIs). SSRIs work by blocking the reuptake of excess serotonin meaning more serotonin is available to help combat symptoms of depression. Although SSRIs don’t have near as many possible lethal side effects as MAOIs they can still be very dangerous if mixed with other antidepressants. The typical side effects of SSRIs include fatigue, weight gain and sexual dysfunction (2015). Additionally, it is common for people to become dependent on their antidepressant medication which results in withdrawal when they discontinue use (2001).
Due to the extensive side effects that are associated with antidepressants and the increasing rates of depression world wide, it is important to find some sort of alternative medicine to deal with symptoms. Exercise should be considered one of these alternative medicines. The mental health benefits have been shown in studies for some time now. One study done twenty-five years ago for example showed that consistent exercise over a one-year period was found to significantly decrease stress and anxiety while significantly increasing sleep quality, confidence, energy, alertness and general mood (1993). Another study that was done after that investigated the minimum length and intensity that was required for psychological benefits to be present. This study found that a significant quality of life improvement was reported after a month. This month consisted of only twenty minutes of daily exercise at an aerobic level of around 60% (2001). A third study directly compared the drop out rates of people being placed in an exercise treatment group and a treatment group receiving drug treatment. This study took place over a four-month period and quality of life improvements were tracked as well. At the end of this study it showed that both treatment groups reported significant increases in quality of life, while there was found to be no significant difference in regard to the drop-out rates between the two groups (2002). The similarity in drop-out rates is somewhat surprising considering the different demands that are placed on a group exercising regularly and a group that is taking medication regularly. There is no doubt that these results support exercise as a form of possible alternative medicine to help control depressive symptoms without the side effects associated medication. However, considering the length of each study it seems that exercise must take place consistently over a long period of time (over a month) to maximize benefits. This was supported by a more recent study done reviewing over thirty studies on the topic of exercise and depression (2012).
As the above studies suggest, exercise definitely has a positive effect on depression. Now what the above studies don’t have an answer for is why? One of three hypotheses is typically suggested as the answer to this question. The first is the endorphin hypothesis. The idea behind this hypothesis is that the stress your body is put under during exercise forces your body to produce endorphins (natural painkillers) which then reduces depression. A second is the monoamine hypothesis. This hypothesis suggests that the effects of exercise on depression are due to exercise increasing the production of neurotransmitters (serotonin & dopamine) similar to the way that antidepressants do. The final hypothesis is based on Albert Bandura’s self-efficacy theory. Self-efficacy is one’s confidence in their own abilities to complete certain tasks or meet certain demands (1994). This is the mastery hypothesis. The idea behind this hypothesis is that the psychological benefits of exercise are experienced because of the mastery felt when completing an exercise. Mastery experience is the strongest of Bandura’s four sources of self-efficacy and has been shown to increase self-worth (2012).
Depression is a very complex illness that seems to impact everybody suffering from it in different ways. For this reason, it is likely that the explanation for the psychological benefits of exercise is a mix of these theories all depending on the person. The consistent thing here is that exercise does have numerous mental health benefits. Is it a coincidence that as physical activity rates have decreased the prevalence of mental health issues has increased? Or that rates of depression have been shown to be higher in individuals who aren’t physically active? That is something you can decide for yourself but given the increasingly high number of people who are suffering maybe consistent exercise is at least worth a shot.
100 Words or Less
Well if you didn’t want to read the entire blogpost I hope you’re sitting down because this might come as a shock to some people, but exercise is good. Yes, you are reading that correctly. It turns out to go along with all those physiological benefits there are also numerous mental health benefits. Basically, exercise over a prolonged period seems to have an impact that is similar to antidepressants without the side effects. So, if you’re feeling down for whatever reason I would recommend giving consistent exercise a shot.
Artino, A. R. (2012). Academic self-efficacy: From educational theory to instructional practice. Perspectives on Medical Education,1(2), 76-85.
Bandura, A. (1994). Self-Efficacy. Encyclopedia of Health and Behavior,4, 71-81.
Ferguson, J. M. (2001). SSRI Antidepressant Medications. The Primary Care Companion to The Journal of Clinical Psychiatry,03(01), 22-27.
Hansen, C. J., Stevens, L. C., & Coast, J. R. (2001). Exercise duration and mood state: How much is enough to feel better? Health Psychology,20(4), 267-275.
Herman, S., Blumenthal, J. A., Babyak, M., Khatri, P., Craighead, W. E., Krishnan, K. R., & Doraiswamy, P. M. (2002). Exercise therapy for depression in middle-aged and older adults: Predictors of early dropout and treatment failure. Health Psychology,21(6), 553-563.
King, A. C., Taylor, C. B., & Haskell, W. L. (1993). Effects of differing intensities and formats of 12 months of exercise training on psychological outcomes in older adults. Health Psychology,12(4), 292-300.
Lox, C. L., Martin, K. A., & Petruzzello, S. J. (2017). The psychology of exercise: Integrating theory and practice. London: Taylor & Francis.
Rimer, J., Dwan, K., Lawlor, D. A., Greig, C. A., Mcmurdo, M., Morley, W., & Mead, G. E. (2012). Exercise for depression. Cochrane Database of Systematic Reviews.
Santarsieri, D., & Schwartz, T. (2015). Antidepressant efficacy and side-effect burden: A quick guide for clinicians. Drugs in Context,4.