Depression causes significant disability in older persons. Up to 18 percent of nursing home residents may be affected. Major depressive disorder has been associated with a 59 percent increase in mortality risk during a one-year follow-up period. As many as 35 percent of older patients do not respond to antidepressant medications. Studies have suggested that exercise training has a beneficial effect in older, healthy, nondepressed adults. Blumenthal and associates assessed the effectiveness of an aerobic exercise program compared with antidepressant therapy for treatment of major depressive disorder in older patients.

A total of 156 patients (50 to 77 years of age) with major depressive disorder was assigned randomly to a program of aerobic exercise, sertraline (50 to 200 mg per day) or combined exercise and medication. Subjects attended three supervised exercise sessions per week for 16 consecutive weeks. Thirty-two patients dropped out before completing the protocol.

Patients in the exercise and combination groups showed significant improvement in aerobic capacity, while patients in the medication group did not show this much improvement. Patients in the exercise group achieved an 11 percent improvement rate in aerobic capacity, patients in the combined treatment group achieved a 9 percent improvement rate and patients in the medication group showed less than a 3 percent improvement rate.

All three groups exhibited a significant decline in depression symptoms. The percentage of patients who were no longer classified as clinically depressed at the end of the four-month treatment period did not differ across treatment groups. Depressed patients in the medication group exhibited a more rapid therapeutic response (within the first few weeks) compared with patients in the other groups. Mildly depressed patients appeared to respond more quickly to the combination of medication and exercise than did moderately to severely depressed patients. By 16 weeks, the groups had all improved on each measure of anxiety, self-esteem, life satisfaction or dysfunction.

Results of this study support the notion that a group program of aerobic exercise is a feasible and effective treatment for depression in older patients. Patients appeared to achieve significant clinical improvement with exercise training. Depression scores indicated that clinical symptoms were significantly reduced in the exercise group. The exercise was as effective as medication after 16 weeks of treatment. The rate of clinical response appeared to vary as a function of depression severity. The patients who received medication alone appeared to have the fastest response to treatment. Patients with less severe depression appeared to respond more quickly to the combination of exercise and medication than their more severely depressed counterparts.

The authors conclude that exercise is comparable to antidepressant agents in the treatment of depression in older adults. The authors also suggest that because the exercise was performed in a group setting, it is possible that the social interaction may have had a beneficial effect on reduction of depression.