Effects of Aerobic Exercise on Depression
By Athena Ives 2012
Millions of people around the world suffer from depression. There are many forms of treatment to include: All forms of psychotherapies, medication, and numerous others. There are nine symptoms for major depression: loss of weight when no dieting or change in appetite; feeling fatigued or lack of energy; insomnia or hypersomnia; behavior that is agitated or slowed down; reduced ability to think, concentrate, or make decisions; thoughts of worthlessness or extreme guilt almost daily; and frequent thoughts of death or suicide (American Psychiatric Association, 2002). The ICD-10 also adds a 10th symptom which is low self-esteem (World Health Organization, 2002).
The Diagnostic and statistical manual of mental disorders (DSM) rates the seriousness of depression. Individuals displaying up to four symptoms are considered mild and can maintain their social and working activities. Those with moderate depression show signs of six symptoms or less and have great difficulty maintain levels of social and working activities. Last of all, individuals displaying seven or more symptoms have severe depression and their personal, social, and working functions are seriously restricted (American Psychiatric Association, 2002).
During the 1980’s lack of physical exercise was listed as being directly responsible for seven of the ten main causes of death. Due to this belief, extensive research was conducted on the link between physical exercise, physical disease, and psychological disorders (Cerda, 2011). Exercise, specifically aerobic activity, began to be considered as one therapeutic treatment to prevent and improve depression (Morilla, 2011). Aerobic exercise is defined as an exercise that is designed to increase oxygen consumption and improve functioning of the cardiovascular and respiratory systems. It has been shown to reduce anxiety and mild to moderate depression in men and women of all ages (Cerda, 2011). Weinberg and Gould (1996) considered that physical exercise influenced psychological well-being by its engaging effect. They also believed that it was the perception of improvement through means of physical exercise distracting the individual from stressful events more than to the activity itself (Weinberg, 1996).
During Exercise the brain releases hormones related to pleasure, euphoria, happiness, and pain relief. This journal article formed the following hypothesis: There would be a significant difference in depression scores between a group of patients with moderate depression scores participating in an aerobic program as a complement to Fluoxetine (20mg) therapy and those only receiving Fluoxetine (20mg) therapy (Cerda, 2011).
To support this hypothesis, research was conducted on 82 participants. The participants were all women averaging 32.4 years of age, from the Jean y Marie Thierry Health Centre of Valparaiso, and were diagnosed with moderate depression. The independent variable would be the type of treatment and the levels would be Aerobic combined with Fluoxetine and Fluoxetine only. The dependent variable is the response rate of the women or how the women reacted to the aerobic exercise combined with Fluoxetine compared to the women only taking Fluoxetine. This is measured by difference in depression rating.
To make this diagnosis, the Beck Depression Inventory and the International Classification of Diseases-Depression (ICD-10) were used (Cerda, 2011). Total sum ranges from 0-63. The higher the total score, the higher the depressive symptoms. The Center for Cognitive Therapy set the BDI Scores as the following:0-9 minimal depression, 10-19 moderate, 20-29 moderate, 30-63 is severe. The Ministry of Health of Chile used the Diagnosis and Treatment Program of Depression based off of the ICD-10. This model takes into account the amount, type, and severity of the symptoms. The ICD-10 and the BDI, were both used to rate depression in this research.
They used a nonprobability sampling technique. The women were selected according to the following criteria: between ages 20-64, physically and mentally able to exercise, compatibility with physical exercise, receiving the (20mg) of Fluoxetine and no additional medication, and no previous history of substance abuse (Cerda, 2011). .
Those participants in the exercise group performed an aerobic training program to include cardiovascular exercise to increase heart and lung function. For 8 consecutive participants exercised on Wednesday, Thursday, and Fridays for 45 minutes and progressed to 60 minutes. During each session the participant went through 3 stages. First, an initial warm up to ensure no injuries occurred. Second, they performed a central exercise of major difficulty and oriented to cardiovascular work. Last of all they would cool down. The central exercises performed during the second stage varied from low-impact aerobics, dancing, and walking (Cerda, 2011).
Each participant received pharmacotherapy taking (20mg) of Fluoxetine which is a selective serotonin reuptake inhibitor. To compare these two groups, a mixed-model analysis of variance (ANOVA) was used (Cerda, 2011).
The exercise/Pharmacotherapy group had moderate depression levels prior to the test and the Pharmacotherapy group had a higher mean score. There were no signs of significant difference between the exercise/Pharmacotherapy group and the Pharmacotherapy group which ensures the homogeneity of the two groups (Beck, 1998).
Table 2 shows that those participating in the Pharmacotherapy/Exercise group decreased their moderate depression score to 58.5% on their BDI and 6.5% on their ICD-10. These patients went from being moderately depressed to minimally or no depression. However, Pharmacotherapy group members only decreased their BDI to 53.5% and their ICD-10 to 41.5%. These patients went from moderate to mild depression (Cerda, 2011).
To summarize the variance the main effect of group (F=18.58, p=.001; n=0.19) and time (F=461.91, p=.001, n=0.85; Table 2). The interaction of the two factors were significant (F=26.74, p<.001; n=0.25). The Tukey HSD post hoc test found in Table 3, indicated that the Pharmacotherapy/Exercise group scored significantly higher at posttest than at pretest (p<.001). Results found in Tables 1, 2, and 3 (Cerda, 2011).
Major Findings and Implications
This research was conducted to discover if an aerobic training program combined with pharmacotherapy had better results than a program solely on Fluoxetine. The results of this research demonstrated more improvement in lowering depression scores from the aerobic group. During the pretest all the participants in both groups scored in the moderate depression area.
Several factors may have led to these results. For some of the participants the exercise may
have been a leisure activity and a social event creating a positive affect amongst participants. Some participants felt better about themselves after working out which also contributed. Along with the social/environmental aspects, the release of hormones during exercise also may be a reason why the exercise group had lower levels of depression after the trial.
Problems with the Research
The demographic was very small and left out many factors. They did not cover male genders, different age groups, or social economic status. All of the women were from middle income families. The ability to socialize and get out of their homes may have attributed to the results. Would this research have shown the same results for women in a higher or lower economic status? This research may have been improved by selecting both male and female genders, a wider economic status selection, and different types of aerobic exercise.
Does this research support the hypothesis? There would be a significant difference in depression scores between a group of patients with moderate depression scores participating in an aerobic program as a complement to Fluoxetine (20mg) therapy and those only receiving Fluoxetine (20mg) therapy. The research has supported that this group of women showed greater improvement combining aerobic exercise and Fluoxetine than those that only took Fluoxetine. However, they should have specified the target group in the hypothesis. The research supported the statement, but it was a very weak support.
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