Suffering from a chronic illness can drain a person's quality of life, but add in depression, and the results are debilitating. A new study from University of Georgia researchers shows that exercise training can reduce depression symptoms in patients with a chronic illness.
In a study published in a recent edition of the Archives of Internal Medicine, researchers analyzed the results of 90 randomized controlled trials involving more than 10,500 sedentary patients with a chronic illness. The study did not focus on patients diagnosed with depression.
"The symptoms of depression that often accompany a chronic illness can lead to a reduced quality of life among patients through restrictions in social and recreational activities, lower adherence to doctors' recommended lifestyle changes that reduce future health risks, and increased disability and health care costs," said Matthew Herring, who led the study during his dissertation research as a doctoral student in the UGA College of Education's department of kinesiology. "Also, because some evidence has questioned how effective antidepressant medications are among patients with a chronic illness, there has continued to be interest in alternative therapies including exercise."
Herring is now a research associate in the department of epidemiology at the University of Alabama at Birmingham. The team also included Patrick O'Connor and Rodney Dishman, co-directors of the UGA exercise psychology laboratory, and Timothy Puetz, who earned his doctorate at UGA.
The patients typically participated in strength or aerobic exercise training for 17 weeks, with three sessions per week, 42 minutes per session. The reduction in symptoms was significantly larger in patients who performed moderate to vigorous physical activity as recommended.
The study builds on the researchers' findings published in Archives of Internal Medicine in February 2010 that regular exercise reduces patient anxiety by 20 percent.
"Our findings are important because millions of Americans suffer from a chronic medical condition, such as cardiovascular diseases, cancers, obesity, pain and fatigue that can present a barrier to being physically active," said O'Connor. "Our results show that when individuals with medical conditions such as these adopt and maintain a program of regular exercise, they report feeling happier and less depressed. The results provide health care professionals with additional evidence for recommending physical activity to their patients."
Among the nine types of patients studied, those with lung and cardiorespiratory disease as well as obesity showed the largest magnitude of improvement in depression symptoms after exercise training.
This finding is particularly timely due to the recent launch of UGA's Obesity Initiative, which addresses adult and childhood obesity and its related diseases. Advances in research and efforts in outreach aim to improve the health of Georgia's citizens and decrease the cost of health care in the state.
"The results also dispel the skeptical view that people feel better when they exercise only because they expect to," said Dishman. "The studies we reviewed were planned to study chronic diseases, not mental health. Patients wouldn't have been expecting a drop in depression. Also, the reduction in depression depended in part on a favorable change in the primary outcome of the study, such as physical functioning or weight loss. So, lower depression was an unexpected, added value of exercise. Our work during the last 15 years using animal models of depression confirms that exercise alters brain biology in ways that can explain these anti-depressant effects of exercise."
The findings warrant further study, particularly on patients with a chronic illness who have been diagnosed with depression.
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For a PDF of the study, see archinte.ama-assn.org/cgi/reprint/172/2/101