DALLAS, May 2 (UPI) -- Doctors should not prescribe combinations of antidepressant medications for patients with major depressive disorder, U.S. researchers say.
Principal investigator Dr. Madhukar H. Trivedi, professor of psychiatry of the University of Texas Southwestern in Dallas, says researchers at 15 sites nationwide studied 665 patients ages 18-75 with major depressive disorder. Three treatment groups were formed and prescribed antidepressant medications already approved by the U.S. Food and Drug Administration.
One group received escitalopram -- a selective serotonin reuptake inhibitor and a placebo. The second group received the same selective serotonin reuptake inhibitor paired with bupropion, a non-tricyclic antidepressant, and a third group took different antidepressants -- venlafaxine and mirtazapine.
After 12 weeks of treatment, remission and response rates were similar across the three groups: 39 percent, 39 percent and 38 percent, respectively, for remission, and about 52 percent in all three groups for response.
The study, published online Monday ahead of print in the American Journal of Psychiatry, found after seven months of treatment, remission and response rates across the three groups remained similar, but side effects were more frequent in the third group, which was prescribed two antidepressant medications.