Exercise may match drugs for treating major depression


A brisk 30-minute walk or jog three times a week may be just as effective in relieving major depression as are standard antidepressant drugs, researchers have found.

In the study, 156 patients diagnosed with major depressive disorder (MDD) were assigned to three groups: exercise, medication, or a combination of medication and exercise. To the surprise of the researchers, after 16 weeks all three groups showed similar--and significant--improvement in measurements of depression.

“One of the conclusions we can draw from this is that exercise may be just as effective as medication and may be a better alternative for certain patients,” said psychologist and study leader James Blumenthal. The team published the results of its research, supported by the National Institutes of Health, in the October 25, 1999, issue of The Archives of Internal Medicine.

“While we don’t know why exercise confers such a benefit, this study shows that exercise should be considered as a credible form of treatment for these patients,” he said in an interview. “Almost one-third of depressed patients in general do not respond to medications, and for others, the medications can cause unwanted side effects. Exercise should be considered a viable option.”

Although the researchers studied middle-aged and elderly people, the results probably hold true for the general population, Blumenthal said.

Symptoms of MDD, as defined by the psychiatric reference book Diagnostic and Statistical Manual IV, include depressed mood or loss of interest or pleasure combined with at least four of the following: sleep disturbances, weight loss, changes in appetite, psychomotor agitation, feelings of worthlessness or excessive guilt, impaired cognition or concentration, and recurrent thoughts of death.

Based on this definition, 60.4 percent of the patients who only exercised were no longer considered depressed after 16 weeks, compared with 65.5 percent for the medication group and 68.8 percent of the combination group. When a second commonly used measure of depression, the Hamilton Rating Scale for Depression, was added, 47.2 percent of the exercise group were no longer considered depressed, compared to 56 percent of the medication group and 47 percent of the combination group. In all cases, according to Blumenthal, the differences between the groups were not statistically significant.

The researchers did note that patients who took the antidepressants saw their symptoms relieved sooner, but by 16 weeks the group differences had disappeared. The drug used in the study was sertraline (trade name Zoloft), which is a member of a class of commonly used antidepressants.

Blumenthal said it was possible that the structured and supportive atmosphere of the exercise program also could have had an effect in improving the symptoms of the exercise group, but he doesn’t attribute the majority of the benefit to social support. Nevertheless, he plans to begin a new study to gauge the effect of exercising in a less-supportive atmosphere, as well as a study to include a placebo group.

Blumenthal suggested that exercise may be beneficial because patients are actually taking an active role in trying to get better.

“Simply taking a pill is very passive,” he said. “Patients who exercised may have felt a greater sense of mastery over their condition and gained a greater sense of accomplishment. They may have felt more self-confident and had better self-esteem because they were able to do it themselves, and they may have attributed their improvement to their ability to exercise.

“These findings could change the way some depressed patients are treated, especially those who are not interested in taking antidepressants,” Blumenthal said. “Although these medications have been proven to be effective, many people want to avoid the side effects or are looking for a more ‘natural’ way of feeling better.”

The Duke research team included Michael Babyak, Kathleen Moore, Steve Herman, Parinda Khatri, Robert Waugh, Melissa Napolitano, Leslie Forman, Murali Doraiswamy, and Ranga Krishnan. Other team members included Edward Craighead of the University of Colorado at Boulder and Mark Applebaum of the University of California at San Diego.

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