Most medical scientist and psychiatrists have defined depression as a mood disorder that often results to incessant feeling of extreme sadness and loss of interest in most activities that one used to enjoy. Depression has various references; the condition could be referred to as major depression, major depression disorder or clinical depression. Depression results to a variety of emotional and physical problems because the condition affects one’s thinking and behavior. Depressed people find difficulty in doing everyday tasks and experience severe hopelessness.
Depression affects 19 million adult Americans, meaning it is the leading mental disorder in the U.S. Studies rank depression second in causes of life lost as result of premature death. Only 23% 0f depressed people seek treatment and only 10% receive adequate care. Common symptoms of depression include loss of interest, fatigue, and feeling of worthlessness. Change in weight, loss of appetite, and change in sleep patterns. Numerous researches have revealed that the use of pharmacological and psychological therapies have resulted to improved health of depressed people. In addition to the two therapies, some researchers have suggested that exercise therapy would have a positive impact on depression patients Harris & Moose (2006). The study sort to find out if there is any cause and effect relationship between exercise and depression
Purpose of the Study
The purpose of the study was to carry out research to determine the potential benefits exercise may have on depressed individuals. The study would further determine if exercise could replace pharmacological, behavioral and psychological therapies or if exercise would be used alongside the three major therapies for better results in treating depression. The study would also add to the available repository for researchers and academicians to refer to by acting as a reference paper and a source of secondary data for future research and academic studies (Harris & Moose, 2006).
Several epidemiological studies have indicated that individuals who participate in more physical activities are less likely to develop depression (Farmer et al., 1988; Kritz-Silverstein et al., 2001; Strawbridge et al., 2002). For example Camocho, Roberts, Lazarious, Kaplan and Cohen (2004) established that when the age, gender and physical disability were adjusted. Individuals with reduced physical activity had a higher risk of developing depression compared to the reference group that was involved in more physical activity (adjusted OR= 4.22, 95% CL: 3.17, 6.62). In another study Krietz-silverstein, Brrett-Connor, and Corbeau (2001) established that; when the intensity and frequency of physical activities were increased, lower scores on Beck Depression Inventory (BDI) was registered. Scientists are yet to establish a causal relationship between physical activity and depression. It is hypothesized that exercise increases the production of serotonin and endorphins chemicals which are responsible for the reduction of stress reactivity and improvement of moods (Dunn & Chambliss, 2010).
The causal relationship between exercise and depression has produced mixed results. Some studies have failed to find any causal relationship for example; Keritz-Silverstein et al. (2001) found no association between BDI scores and baseline exercise with a follow-up period of five years. The inconsistency could be attributed to several issues for instance, the definition of exercise is diverse, the definition ranges from simple gardening to intense physical activity. The second issue is the use of two waves of data; most longitudinal studies use two waves of data instead of more waves of data. Use of two waves of data limits precision and reliability of the studies (Dunn & Chambliss, 2010).
The current studies have tried to address the inconsistencies by only focusing on depressed patients at the baseline rather than community-based non-patients samples as had been applied in the prior studies. Current studies have also incorporated personal meaning and function of physical activities during the studies, an approach that had not been used in the past. The current studies have further looked into other factors that could be responsible for the causal relationship between exercise and depression other than major known factors. For example, the current studies have incorporated use of reverse causal hypothesis and buffering hypothesis (Dunn & Chambliss, 2010).
Conceptual frameworks or models are used to guide research studies in many areas including nursing practice. Conceptual framework summarizes the study comprehensively, logically and clearly. A conceptual framework reveals how an intervention works and the factors that improve the effectiveness of the intervention. The study lacked a nursing framework meaning that a summarized guide about the study could not be derived; a reader had to peruse through the whole study to get a gist of the concept of the study.
Research Hypothesis and Research Questions
There is a cause and effect relationship between physical exercise and depression
What are the major causes of depression in children, teens and adults?
How might exercise help alleviate depressive symptoms?
What exercises are best for individuals who would like to improve mood and reduce depressive symptoms?
Because the study aims to determine the cause and effect relationship between physical exercise and depression, strict interpretation of independence and dependence variable as cause and effect cannot be used. However, most studies presume exercise as the cause of reduced depression; exercise, therefore, serves as the independent variable in the study (Dunn & Chambliss, 2010).
The study used 2 * 2 factorial designs, plus an exercise placebo control group. The exercise consisted of two factors that involve weekly expenditure of energy (7kca/kg/ week for Long Dose [LD] or 17.5kcal/kg/week for public health dose [PHD]) with a frequency of three days or five days a week. The Exercise used the American College of Sports Medicine guidelines and Public Health recommendation for physical activities to determine the dose. The frequency of the control group was less than 3 days and lasted for less than 20 minutes. Factorial designs are useful statistical tools; the designs are vital in optimization of experiments; resulting to maximum information in a small number of experiments. The design allowed generalizability of the results and interaction of the variables. The control group also allowed sound comparison and reasonable conclusion based on facts rather than assumptions (Dunn & Chambliss, 2010).
Validity of the Study
. Validity is the meaning one gets by interpreting the results of a study. Validity answers questions such as does the research measure what was intended to be measured and does the research instrument allow one to achieve the intended research objectives Drost (2012). From glancing at the study, one would easily conclude that the study actually measured the relationship between exercise and depression, meaning face validity was achieved. The study had a high internal validity because the study explored many forms of exercise that could be used to explain the cause and effect relationship between exercise and depression. The high internal validity jeopardized the external validity; it is, therefore, unclear whether the use of the study could be generalized to the clinical practice (Dunn & Chambliss, 2010).
The Efficacy of the Study
The study was to explore the availability of any cause and effect relationship between exercise and depression. The study addressed the research question and determined that there is adequate scientific proof to conclude that exercise alleviates depressive symptoms and may be an alternative depression treatment therapy. The group in the factorial design had significant improvement on the depressive symptoms when compared to the control group (Dunn & Chambliss, 2010).
The study did not discriminate against participants based on race, ethnicity or gender during the selection. The participants had the right to withdraw from the study whenever they felt that the study was of no benefit, for instance, some participants who considered being assigned to the placebo group unacceptable dropped out the exercise immediately. The participants engaged in the study willingly without any coercion. Before participating in the study, the participants consented to the process of the study. American College of Sports and the department of public health certified the safety of the study and authorized the process to commence (Dunn & Chambliss, 2010).
Cultural Aspect of the Study
The study was not focused on any cultural aspect; it focused on the outcome of exercise on the depressed people on randomly picked patients. A focus on a specific culture, for example, Hispanic adults would give more definite results of effects of exercise on depression on the given population. Such results would be important in implementing treatment strategies especially to populations that are prone to depression.
The study participants consisted of (n=80). Both men and women participated in the study, and the ages ranged from 20 to 45 years. The participants had a score of 12 to 16 for mild depression and a score of 17 to 25 for moderate depression on Hamilton Rating Scale for Depression (HRCP); the diagnosis of the participants was done using Structural Clinical Interview for Depression (SCID), and adhered to the Diagnostic and Statistical Manual of Mental Disorder fourth edition (DSM-IV). The participants must have been living a sedentary life. Meaning the participants exercise routine was less than three times weekly and lasted for less than 20 minutes. The participants must not have received any other treatment for depression and could understand the content of informed consent (Dunn & Chambliss, 2010).
The participants were divided into energy expenditure group of 3 or 5 days per week; 33 in LD, 34 in the PHD and 13 in the control. Women outnumbered men in the ratio of 3:1, the medium age was 35.9 years, and the inter-quartile range was 31 to 41. The placebo controlled group was defined by three days exercise per week lasting between 15 to 20 minutes. After randomization participants exercised on treadmill and stationary bicycle under supervision in the laboratory for 12 weeks; individual participants also exercised individually in separate rooms by themselves under supervision. Attending scheduled session defined the treatment adherent (Dunn & Chambliss, 2010).
The major findings of the study were that public health dose (PHD) was effective in reducing symptoms of depression. In efficacy analysis mean HRSD17 scores at the 12th week recorded reduction of 47% from the baseline for the PHD condition group, meaning the response, was significantly better than response experienced in the LD and the control group. 46% of participants in PHD group responded positively to the exercise therapy. Both PHD and LD experienced significant improvement compared to the control condition. PHD (P< 0.001), LD (P= 0.01) and control (p= 0.20). When main treatment was compared at the end of the 12 weeks, PDH condition was significantly more effective compared to the LD condition and the control group in catalyzing reaction to the exercise intervention (p=0.17). In conclusion physical exercise (aerobic exercise) is the amount recommend consensually by public health recommendation as an effective treatment for depression (mild or moderate). PHD dose compares favorably with rates recorded in other treatment therapies such as cognitive behavior pharmacological therapy and psychological therapy (Dunn & Chambliss, 2010).
Impact of the Result to Future Nursing Practice
The result is significant to future nursing practice because nurses would have a better understating of depression as a clinical condition and the relationship between the condition and exercise. Nurses would also make a recommendation for exercise treatment therapy with informed knowledge based on sound scientific evidence. The results also mean that nurses have an extra option to offer patients who are not responsive to the common treatment therapies such pharmacology and psychological counseling. The study has also ignited more research on the most effective exercise option for depression; so that patients participate on more specific exercise. A more specific exercise would mean more appropriate positive outcome (American Association of Critical Care Nurse, 2013).
Application of the Result to Student Nursing Practice
Nursing practice depends on specialization of knowledge and skills and autonomy of decision making. The focus of nursing practice varies depending on clients, setting, the diseases or condition. The study enriches the understanding of exercise and depression among the students. The study also adds to the rich compilation of literature for the students. The teaching of the concept to students would help the student make informed autonomous decision when choosing exercise an alternative treatment method; because the method is supported with sufficient scientific evidence. The study also challenges the students to do further research on the concept of exercise and depression to fill the gaps that most studies are yet to find answers to; such as how exactly does exercise reduce symptoms of depression what organs and chemicals are involved (American Association of Critical Care Nurse, 2013)
Drost, E. (2012). Validity and Reliability in Social Science Research. Education Research and Perspectives, 38, 106-103.
Dunn, A., & Chambliss, H. (2010). Exercise Treatment for Depression Efficacy and Dose Response. American Journal of Preventive Medicine, 1, 1-8.
American Association of Critical Care Nurse. (2013). American Association of Critical Care Nurse. AACN Scope and Standards for Acute Care Nurse Practitioner Practice, 13.
Harris, A., & Moos, R. (2006). Physical activity, exercise coping, and depression in a 10-year cohort study of depressed patients. Journal of Affective Disorders, 93, 79–85-79–85.