Exercise May Serve As "Medicine" for Depression

Supporting the interconnection between mind and body, a recent study has found that exercise can serve as a supplemental treatment for 50% of patients with depression who have not been cured by a single antidepressant medication. The amount and type of exercise, much like the dose of a prescribed medicine, needs to be customized to the individual.

“Many people who start on an antidepressant medication feel better after they begin treatment, but they still don’t feel completely well or as good as they did before they became depressed,” said lead study author Madhukar Trivedi, MD, professor of psychiatry at the University of Texas Southwestern Medical Center in Dallas (UT Southwestern).

Since exercise has successfully helped those with depression and is known to affect neurochemicals that also play a role in depression disorders, researchers from UT Southwestern and The Cooper Institute in Dallas decided to evaluate whether exercise, prescribed in treatment doses, could alleviate depressive symptoms. The study, conducted over a 4-year period, was a randomized trial including 126 men and women, aged 18–70, who had all been diagnosed with major depression disorder, had received antidepressant medications, but had not fully overcome their symptoms.

Investigators divided 126 subjects into two groups—a higher-dose exercise expenditure of 16 kilocalories per kilogram of body weight per week (KKW) and a lower-dose exercise expenditure of 4 KKW. Each group followed its exercise program for 12 weeks. Sixteen KKW is equivalent to walking at about 4 miles per hour for 210 minutes per week, whereas 4 KKW is equivalent to walking at about 3 miles per hour for 75 minutes per week. Researchers collected data on whether depressive symptoms had lessened.

Data assessment showed that almost 30% of patients in both groups experienced relief from their depression, while another 20% exhibited significant improvement. Moderate exercise was more beneficial to women with a family history of mental illness, while intense exercise helped those with no such history. Men, regardless of family history, showed more improvement with a higher volume of exercise.

“This is an important result in that we found that the type of exercise that is needed depends on the specific characteristics of the patient, illustrating that treatments may need to be tailored to the individual,” said Trivedi.

Study limitations included the absence of a control group and the fact that lower-dose exercise participants adhered better to their program. More research was recommended with a true control group, a larger sample size and a study of longer-term outcomes, among other factors.

The study was published in the Journal of Clinical Psychiatry (2011; 72 [5], 677–84).