Yet another study is calling the efficacy of antidepressants into question. New research published in the Journal of the American Medical Association suggests that only patients with severe depression truly benefit from the drugs. Those suffering from mild to moderate depression get little or no help from those drugs, and that help may simply be due to seeing a doctor, learning about depression, and other circumstances, the researchers conclude.
What about all those studies that show antidepressants work better than placebo? You know, the studies that helped these drugs get approved? Well, the researchers told the Los Angeles Times that many studies only include patients with severe depression. "[T]here is a tendency to generalize the findings to mean that all depressed people benefit from medications," lead author Robert J. DeRubeis of the University of Pennsylvania said.
The researchers looked at six randomized, controlled studies with a total of 718 patients, who were adults with levels of depression ranging from mild to very severe according to a common depression-rating scale. Scores on that scale at the beginning of the study and at the end were compared. Very severely depressed patients who took antidepressants had a significantly larger improvement in their scores than did very severely depressed patients who took placebo. But mildly to moderately depressed patients using placebo saw about the same improvement as those who took the drugs.
Other studies have come to similar conclusions. But as the Wall Street Journal Health Blog points out, this doesn't necessarily mean that antidepressant drugs don't work in mildly depressed folks. It may just mean that placebo works against mild depression, too.