Are Antidepressants Just Placebos?

"Antidepressants' Benefits May Be Exaggerated." "Antidepressants Under Scrutiny Over Efficacy." "End of the Prozac Nation?" In early 2008, a pair of studies questioning the track record of antidepressants spawned a rash of headlines like these and led depression patients to wonder if their antidepressants were doing any good.

The first salvo against antidepressants came from a study led by Erick Turner, MD, a psychiatrist at Oregon Health & Science University. After reviewing the entire mass of drug-company studies submitted to the FDA (where he once worked as a reviewer) in the approval process for 12 antidepressants, Dr. Turner and his fellow researchers reported that 94% of the studies with positive results were later published, while only 14% with negative or ambiguous results found their way into print.

This so-called "file-drawer effect" has made antidepressants appear more effective than they actually are, at least to physicians and the public. "There is a view that these drugs are effective all the time," Dr. Turner told The Wall Street Journal. When he would tell other doctors that antidepressants work only 40% to 50% of the time, they would protest, "What are you talking about? I have never seen a negative study."

The second study, led by Irving Kirsch, a professor of psychology at the University of Hull, in Britain, arrived at a similar conclusion. Kirsch found that when he factored in unpublished data, four widely prescribed antidepressants—all but one of which belonged to the popular class known as SSRIs (selective serotonin-reuptake inhibitors)—worked only marginally better in clinical trials than sugar pills. And even then, the only clinically significant efficacy was observed in severely depressed patients (who are less apt to respond to the placebo effect). "It is time for a change of emphasis to nondrug treatments and [to] reserve these drugs for very severely depressed patients," Kirsch said when the study was released.