Study: Antidepressants, Placebos Near Equally Effective

Jan. 6, 2010 — -- A new analysis found that commonly prescribed antidepressants had little effect on people with cases of mild to severe depression compared to those treated with placebos.

The analysis, published in the Journal of the American Medical Assocation, combined the findings of six different previous studies of two commonly prescribed treatments -- paroxetine, similar to common Paxil, Prosac and Zoloft, and imipramine, an older antidepressant drug.

"The magnitude of benefit of antidepressant medication compared with placebo increases with severity of depression symptoms and may be minimal or nonexistent, on average, in patients with mild or moderate symptoms. For patients with very severe depression, the benefit of medications over placebo is substantial," the study concluded.

The findings do not mean that the drugs or the placebos were frivolous for most users, "Good Morning America" chief medical editor Dr. Richard Besser said today. Rather, both the antidepressants and the placebos had a positive effect on the patients.

"You hear that headline and you think, 'Oh, my God, there is nothing out there that works for depression," Besser said. "The study actually found the exact opposite; that both placebo and medications were extremely effective at treating mild to moderate depression. What you can't tell from this study is what else is going on. Were these individuals getting what is most effective, which is talk therapy?"

The analysis included a pool of 434 patients from the antidepressant group and 284 patients in the placebo group.

Dr. Gary Kennedy, a professor of psychiatry and behavioral science at Montefiore Medical Center, Albert Einstein College of Medicine, said that analysis seemed logical, but was cautious of its conclusions.

"The finding that more severe depression is more likely to respond to antidepressant medication seems sound," Kennedy said. "But only six studies were used to generate the conclusion, and three of those studies used an antidepressant that few practicing physicians would prescribe nowadays.

"However... This is a major line of enquiry at present and offers the hope that we can prevent severe depression if we could identify the trajectory from minor to major depression," he said.