Exercise And Depression
Table of Contents
I. What is "Depression"?
In the most general terms, depression is a "disorder of the brain and bodyís ability to biologically create and balance a normal range of thoughts, emotions, and energy" ( http://suicidal.com/depressionfaq/q1.thm). Although depression is a serious illness that affects one in any five persons at some point in their lives, much of the population is not accurately educated on this disorder. When approached from a strictly scientific angle, depression is a chemical disorder which alters the function of normal brain behavior. Unusual levels of chemicals such as the neurotransmitters beta-endorphin, serotonin, and dopamine cause this disorder. It is believed that not only can depression arise from genetic make up but also through the influences of the environment. For instance, if a child is raised among a depressed family, he is likely to only know how to view life with distorted and negative emotions. Extreme trauma during childhood may also serve as a trigger for this illness (http://www.depression.com/tools/health_library/basics/biochem.html).
Depression can greatly fluctuate in severity. To diagnose each case doctors use the American Psychiatric Association handbook, Diagnostic and Statistical Manual of Mental Disorders fourth edition (DSM ĖIV). The least severe type of depression is often thought of as the "normal" depressed mood. This is considered healthy for it is a natural reaction to a disturbing event, and even more because the sufferer will recover. The next level of severity deals with adjustment disorders. This stage is considered more serious solely because it is more common that those suffering with such depression are not as likely to recover in time on their own. Dysthymia, or mild depression, is the next level of depression. The symptoms for this stage include chronic depressed moods and low self-esteem. Dysthymia is often treated through therapy and/or medication. Despair and utter hopelessness are two just symptoms that characterize the next level called major depression. Not only do sufferers of major depression have low self-esteem, but they also lose their interest in life. For many, major depression includes the inability to get out of bed or even to eat. Often times, major depression can occur without any identifiable causes. At this stage, suicide is often contemplated. Manic-depression, or bipolar disease, differs from major depression in that the suffererís chronic depression is counter balanced by inexplicable bursts of excessive energy. Seasonal Affective Disorder (SAD) also strays from major depression. This type of depression is only brought on during certain types of weather conditions, such as the lack of sunlight in winter. The usual cycle involves severe depression from the late fall until the early spring.
With this information, it becomes clear just how complex and individualistic each case of depression can be. Yet at whatever levels oneís depression rests, the side effects of this illness alter all aspect of the body. From sleeping habits to psychological stability, sufferers of this illness most often require some variety of treatments to gain control over their depression. When treated, however, over eighty percent of those suffering from depression are successfully aided.
II. How is depression treated?
There are numerous methods of treatment for this illness. The two most common treatments are antidepressant medications and counseling. The first antidepressant, monoamine oxidase (MAO), was accidentally created in the 1950ís. Scientists were hoping to find a new drug to treat tuberculosis and instead discovered MAO helped to raise oneís mood. Currently, there are numerous different antidepressants on the market, and most depressed people can find a medication that works considerably well. In fact, it is estimated that antidepressants can raise oneís mood anywhere from 60% to 80% when used properly. In most cases however, sufferers of depression have to try a few different drugs until they find the right medicine for their body(http://www.depression.com/tools/health_library/treatments/antidepressants.html). When beginning such medication, sufferers often struggle with depression for up till six weeks until the medicine is able to make any improvement in mood. Such time is need for the medicine to alter the availability of neurotransmitters within the brain.
Although antidepressants have been proven effective, many doctors prescribe counseling or psychotherapy as an additional method of treatment. The basic principle behinds such treatments stem from Freudian psychoanalysis. The idea is to first help the individual identify his or her issues and then to help them cope with the accompanying emotions. Such treatment has proven to be quite effective for moderate depression in particular. According to a study performed by the National Institute of Mental Health, after approximately sixteen weeks of psychotherapy 55% of those suffering with depression experienced notable improvement(http://www.depression.com/tools/health_library/treatments/psychotherapy.html).
CBT, or cognitive behavior therapy, is currently one of the most accepted and useful methods for aiding depression. This is a relatively new approach through which the therapist works directly with a patient in order to identify the portion of the patientís negative thinking that is problematic. By determining which element of thought or behavior is hindering the patientís feeling of happiness, the therapist then teaches the patient how to successfully manage the situations(http://www.nacbt.org/).
Other alternative methods that have become acceptable treatments for depression include herbal medicines, dietary supplements and electroconvulsive therapy (ECT). St. Johnís wort, SAM-e, and ginkgo, for instance, are all natural supplements that are used in order to relieve depression. Although some are skeptical of their effectiveness, studies such as the meta-analysis on St. Johnís wort, which was published in the 1996 British Medical Journal, found that this natural supplement worked nearly as well as the prescribed antidepressants(http://www.depression.com/tools/health_library/treaments/herbal.htm). Dietary supplements used to treat depression function in essentially the same manner, by altering various chemicals in the brain. Some of the recommended supplements include B vitamins and folic acids. ECT, on the other hand, is a type of treatment that is not widely accepted despite the positive results it has produced. Also known as shock therapy, ECT is used in order to alter parts of the brain by sending small currents of electricity to the brain.
IV. What is the relationship between exercise and depression?
In addition to the numerous treatments for depression, exercise has become an appealing new alternative to alter oneís mood. Many recent studies have been published supporting the belief that exercise has been proven effective in improving depression and in some cases has been able to prevent it all together.
The basic reasoning behind this theory is that exercising has positive effects on oneís body and mind. In support of the psychological benefits, it is argued that exercising increases oneís self-confidence as well as provides a feeling of accomplishment and mastery, which in turn may raise an individualís overall outlook(http://abcnews.go.com/sections/living/InYourHead/allinyourhead_48.html). By compiling the findings from fifty-one different studies, Spence JC found that a small but notable increase in self-esteem was linked to the lowering of depression (http://www.physsportsmed.com/issues/1998/10Oct/artal.htm). In addition to the increase in self-esteem, exercise can also provide a more grounded perspective on life. By participating in group exercise the individual is placed in an environment where it is more likely that he will interact with others. The interaction in itself offers a therapeutic affect for those who are so depressed that they choose not to even get out of bed.
But even more convincing to some is the biological argument that supports the link between exercising and improved depression. Currently researchers are studying the various ways the mind alters oneís mood, placing much of their focus on the brainís neurotransmitters. The two most highly publicized neurotransmitters are beta-endorphins and serotonin. Beta-endorphins are part of the mood regulating chemicals that reduces pain and can even induce euphoria. In fact, it is even now believed that the increase in beta-endorphins when exercising is the true cause of the euphoric state, "runnerís high". However, there are little scientific findings to prove that beta-endorphin has a positive effect on depression(http://www.physsportsmed.com/issues/1998/10Oct/artal.htm).
Serotonin, nonetheless, is another chemical in the brain that has been successfully linked to mood(http://www.ahealthyme.com/article/primer/100017159). In particular, it is responsible for the availability of neurotransmitters at receptor sites. For the brain to maintain a stabilized mood, it must have balanced levels of serotonin. In cases of manic depression, the cause most often stems from either a lack of serotonin in the brain or inefficiency among the serotonin receptors (http://ww2.lafayette.edu/~loerc/ander.html , http://www.biopsychiatry.com/serotonin.htm ) . Most doctors have relied on drugs such as tricyclic antidepressants (TCAs) and specific serotonin reuptake inhibitors (SSRIs) to monitor the levels of serotonin in the brain. However as more studies are being performed on exercise and depression, scientists are hypothesizing that exercise may raise serotonin levels enough so as to help those suffering from depression, an alternative which is inexpensive as well as beneficial for the entire body.
IV. The physiological effects: Can exercise decrease depression?
More conclusive data has been gathered on the effects of exercise on the body. One of the possible explanations of how exercise affects physical activities is found in the monoamine hypothesis. As explained in a review by C. P. Ransford (1982), the monoamine hypothesis is based on the theory that exercise increases the brainís aminergic synaptic transmission. In other words, the monoamines in the brain, such as serotonin and dopamine, have an improved transmission rate when exercising occurs. This is beneficial for those depressed because such chemicals in the brain directly affect oneís mood. Although this theory has received sufficient support from other studies and proven to be a defensible theory, it is still believed to be somewhat oversimplified (Sachar & Asnis, 1980; Nicoloff & Schwenk, 1995; Dunn &Dishman, 1991).
The endorphin hypothesis is but another theory as to how exercise affects the body. This theory has not received very much scientific support except in the fact that extended exercise has been proven to increase the secretion of endorphins (Yeung, 1996; Moore, 1982). Yet it has not been fully proven that such an increase plays a crucial role in the control of moods.
When these detailed hypotheses are generalized into an overall conclusion, it is fair to say that exercise has a beneficial affect on the body itself. This principle that exercise benefits the body has been accept by researchers everywhere. Yet an interesting detail specific to the exercise-depression debate is the fact that some studies within this field of experiments have concluded that moderate exercise proves more effective than strenuous exercise programs when trying to decrease depression. This observation is proven true in the study performed by Moses, Steptoe, and Matthews (1989), where 109 sedentary people were randomly assigned to one out of four groups: high intensity exercise, moderate intensity exercise, attention-placebo or a waiting list. When the ten-week study was completed, researchers found that those in the moderate intensity exercise group were the only ones to show improvement in their levels of depression. It is presumed that the high intensity program added more stress than relief and therefore could not improve depression rates. Further support for this theory can be found in the experiment done by Hassmen, Koivula, and Uutela (2000).
Yet to counterbalance this point made, others have present the theory that any type of exercise and any level of intensity can produce beneficial affects with depression. In a meta-analysis of eighty studies, it was concluded that "the results provided positive support for a relationship between physical exercise and depression. In particular, it was concluded that acute and chronic exercise effectively reduced clinical depression" (Scully, Kremer, Meade, Graham, Dudgeon 1998, p. 112).
V. The psychological effects: Can exercise decrease depression?
As this theory of exercise and depression continues to grow in popularity, more and more studies are being performed to understand the true scientific connections. As discussed in the review "Physical activity and mental health: current concepts", by Paluska and Schwenk (2000), there are three basic theories involved with the connection between exercise and depression, the first being the distraction hypothesis. This theory is based on the idea that diversion from painful stimuli leads to an improved state after exercising. As demonstrated by Bahrkeís and Morganís experiment (1978), distractions from the stress of daily life through exercise caused a beneficial decline in anxiety and depression.
The second theory, the self-efficiency theory, is founded on the idea that one must first have the confidence that he or she can perform a certain behavior. It is thought that when a depressed individual simply becomes motivated enough to perform the act of exercise his or her self-esteem is raised and in turn, depression lessens. Lastly is the mastery hypothesis. This suggests that if one is able to use exercise as a means to gain control and a feeling of mastery, his suffering from depression may slightly decrease. Exercise has been proven to have psychological beneficial effects on clinically depressed individuals. However, it must be noted that little conclusive evidence has been gathered on how directly the two are correlated.
With theories set aside and mere facts and studies from which to gather additional data, it seems that the majority of studies dealing with the psychological affects of exercise all conclude that exercise does have a positive affect on depression. Take for instance the experiment done by Martinsen, Medhaus, and Sandvik (1985) which took a group of forty-three clinically depressed men and women and first measured their mood by the Beck Depression Inventory (BDI). Next, these forty-three patients took part in a nine-week exercise program. Martinsen et al. were able to later conclude that from the decrease in the DBI depressive scores, exercise had improved the patientís moods. The general conclusion from this experiment and others is that exercise, to some degree, can decrease depression in those diagnosed as depressed (Hassmen, Koivula, Uutela 2000).
Similarly in a study by DiLorenzo, Bargman, Stucky-Ropp, Brassington, Frensch, and LaFontaine (1999), the conclusions illustrated that exercise aided the depressed both on short-term and long-term scales. The experiment was such that 111 health adults, none suffering from clinical depression, were randomly assigned to two groups. One group was to use bicycle ergometry twenty-four minutes a session, four times a week for twelve weeks. The other group was to do the same exercise but forty-eight minutes a session, four times a week for twelve weeks. And to make the experiment complete, there was a group assigned to a "waiting list" to serve as the experimentís control. By the end of the twelve weeks, DiLorenzo et al. were able to conclude that not only were physiological benefits occurred, such as a stronger heart, but also psychological improvements were made, specifically with depression. The long-term effects of this experiment showed an overall improvement both physically and mentally which was still present a year after the experiment had occurred. It is important to note that in most experiments the findings suggest that exercise helps minimize oneís depressions but there is little scientific evidence stating that exercise can prevent depression.
Another element in the relationship between and the effectiveness of exercise as a treatment for depression is the level or severity of depression. In the study done by Morgan (1979), it was found that among those who did not suffer from depression, a six-week exercise program had no beneficial affects on their mood. However, a subsample of depressed individuals from the same group studied was taken and the findings showed that these people did experience a decrease in depression. Such findings help illustrated the theory that exercise may only truly be affective when it is used with moderately to severely depressed individuals. For further references of studies illustrating the effectiveness of exercise when dealing with depression, one can visit(http://www.physsportsmed.com/issues/1998/10Oct/artal.htm).
With all this said, it is important to state that no final ruling has been made on the effectiveness of exercise as a treatment for psychological improvements with depression for scientific studies are still suggesting that perhaps there is no correlation between the two at all. This is the case for Dr. Cooper-Patrick who, in a study performed at John Hopkins University, was extremely disappointed when she found that exercise did not prevent depression in any measurable degree (http://web.missouri.edu/~psycmm/abnormal/msg00017.html). After following her subjects for two years, Dr. Cooper-Patrick found that the rate of depression carried no significant difference from the general public.
VI. What exercise is best?
By evaluating the various studies offered on this treatment, there is no one type of exercise that is more effective than another (Doyne, Ossip-Klein, Bowman, et al., 1987). However, as explained in the review article by Paluska and Schwenk (2000), studies have shown that aerobic activity, strength or flexibility training all prove effective in treating depression. This is because the focus of this treatment is not so much meant to be on the cardiovascular exercise and the physiological effects it produces, but more important is the physical activity itself and the effects it carries on the mind. The matter of intensity, as discussed above in The physiological effects: Can exercise decrease depression? section, is still very debatable. However, there seems to be a consensus on the idea that oneís exercises ought to be done continuously for best effects (Osei-Tutu & Campagna, 1998). Lastly, it is important to note that whatever exercise is prescribed, it must be one that is not difficult too fulfill and one that is appealing to the patient. If either of these factors are not met it is very likely that the patient will not be able to benefit from the exercise because these factors would be serving as an impedance to any benefits the physical routine may offer.
VII. Precautions when beginning to exercise as treatment for depression
Like many treatments, precautions must be taken when depressed patients begin to use exercise as a means of treatment. Most often, exercise may not be the only treatment prescribed. Many doctors find that exercise along with psychotherapy and even sometimes antidepressants makes the best combination. However some warnings must be given when mixing such treatments. For instance, if the patient is taking an older tricyclic antidepressant, such side effects such as orthostatic hypertension and sedation may conflict with the patientís ability to perform aerobic exercises. Nonetheless, the newer antidepressants are not as likely to conflict with oneís ability to exercise.
It is also important to mention that some patients may misuse exercise. For instance, those who are suffering from eating disorders, such as anorexia nervosa, may be more prone to become more self-conscious when asked to exercise. Exercise, when not performed in a moderate routine, can become a destructive element to oneís mental and physical health (http://www.physsportmed.com/issues/1998/10Oct/artal.htm).
Finally there is the issue of overtraining which occurs when someone pushes his or her body beyond a certain point of acceptable exercising. In fact, if this occurs while someone is using exercise as a means through which to treat depression, it is most likely that the exercise will begin to work against the original goal. For instance in a study of fourteen health female college swimmers, it was found that their scores on a depression tests increased after their coach greatly increased the exercise routine (OíConnor, Morgan, Raglin, et al., 1989).
There is still much to be learned about the relationship between exercise and depression. However, studies so far have shown undeniable coherency in pointing to the fact that exercise does have beneficial effects on certain levels of depression. Much of the trouble in studying this relationship lies in the fact that each case is unique and individualized. Nonetheless, scientists have made great strides over the years in understanding this relationship between mind and body. But until final conclusions can be made, just remember that exercise as suggested by your physician will always be beneficial to you.
IX. Helpful linkshttp://www.depression.com http://www.physsportsmed.com/issues/1998/10Oct/artal.thm http://suicidal.com/depressionfaq/
Bahrke, M.S., & Morgan, W.P. (1978). Anxiety reduction following exercise:
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