By Hong Mautz
Jan. 17 (CBSHealthWatch)--Adding exercise to the treatment plan for depression may give patients mental as well as physical benefits, according to a new study that suggests exercise may be an alternative treatment for depression.
Until now, there have been no controlled clinical trials that examined the effect of exercise compared to medication in treating clinically depressed patients. In this study, researchers focused on how exercise affected the relapse rate of depression and what kind of effect maintenance of exercise had on depressed patients.
"Exercise was associated with reduced depression, and maintenance of exercise was beneficial for depressed patients," says James Blumenthal, PhD, lead author of the study and professor of psychology at Duke University Medical Center in Durham, North Carolina. "Patients who exercised had much lower relapse rates. Those who continued exercising after the trial had half the risk of being depressed compared to those who did not keep exercising."
Researchers examined 156 patients over the age of 50 who were clinically diagnosed with depression. The patients were divided into three groups: the exercise group, the medication (sertraline, or Zoloft) group, and the combination of both exercise and medication group. Researchers found that after 16 weeks, all three groups showed statistically significant and identical improvement in standard measurements of depression, implying that exercise was just as effective as medication in treating depression.
"Exercise may be beneficial as an alternative treatment for depression, and it may also serve to prevent depression in those who are susceptible to become depressed," says Blumenthal. "Those in remission after 16 weeks had an 8% relapse rate compared to a more than 30% rate in the medication group and the combination group at the end of a 6-month follow-up."
An added benefit of exercise, according to researchers, is that patients improved certain cognitive abilities, such as the so-called executive functions that include planning, organization and the ability to mentally juggle different intellectual tasks at the same time.
"Exercise had its beneficial effect in specific areas of cognitive function that are rooted in the frontal and pre-frontal regions of the brain," Blumenthal explains. "The implications are that exercise might be able to offset some of the mental declines that we often associate with the aging process." But he cautions that further studies are needed not only to clarify specific mental processes that are improved by exercise, but also to better understand the underlying mechanisms of these improvements.
Robert Carney, PhD, professor of clinical psychology at Washington University in St. Louis, Missouri, says that this study is important. "It addressed our concerns about whether patients can maintain the exercise program long enough to clinically benefit," says Carney. "However, it is premature to suggest that exercise may be the sole treatment for depression without relying on anything else. But it is very likely that exercise could be part of the overall treatment regimen, and it would be a very important component to that regiment for effectively treating depression."
Although it is not clear how exactly exercise affects a depressed person, Carney says that one speculation is that depressed patients generally feel hopeless and helpless, and that they feel that they have little control over themselves and the world around them. "Exercise may teach them the sense of self-mastery and control, which may have powerful antidepressant effects," says Carney.
But Carney cautions that the study results have to be replicated and that depressed patients should consult with their doctors before engaging in an exercise program.
The study was dubbed SMILE--Standard Medical Intervention and Long-term Exercise. In the phase two of SMILE, researchers say that they will examine the effect of social support by comparing home-based exercise to supervised exercise in a group setting.
The study is published
in the January issue of the Journal of Aging and Physical Activity.
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