Last month brought an especially high-profile debunking. In an essay in The New York Review of Books, Marcia Angell, former editor in chief of The New England Journal of Medicine, favorably entertained the premise that “psychoactive drugs are useless.” Earlier, a USA Today piece about a study done by the psychologist Robert DeRubeis had the headline, “Antidepressant lift may be all in your head,” and shortly after, a Newsweek cover piece discussed research by the psychologist Irving Kirsch arguing that the drugs were no more effective than a placebo.

Could this be true? Could drugs that are ingested by one in 10 Americans each year, drugs that have changed the way that mental illness is treated, really be a hoax, a mistake or a concept gone wrong?

This supposition is worrisome. Antidepressants work — ordinarily well, on a par with other medications doctors prescribe. Yes, certain researchers have questioned their efficacy in particular areas — sometimes, I believe, on the basis of shaky data. And yet, the notion that they aren’t effective in general is influencing treatment.

For instance, not long ago, I received disturbing news: a friend had had a stroke that paralyzed the right side of his body. Hoping to be of use, I searched the Web for a study I vaguely remembered. There it was: a group in France had worked with more than 100 people with the kind of stroke that affected my friend. Along with physiotherapy, half received Prozac, and half a placebo. Members of the Prozac group recovered more of their mobility. Antidepressants are good at treating post-stroke depression and good at preventing it. They also help protect memory. In stroke patients, antidepressants look like a tonic for brain health.

When I learned that my friend was not on antidepressants, I suggested he raise the issue with his neurologists. I e-mailed them the relevant articles. After further consideration, the doctors added the medicines to his regimen of physical therapy.

Surprised that my friend had not been offered a highly effective treatment, I phoned Robert G. Robinson at the University of Iowa’s department of psychiatry, a leading researcher in this field. He said, “Neurologists tell me they don’t use an antidepressant unless a patient is suffering very serious depression. They’re influenced by reports that say that’s all antidepressants are good for.”

Critics raise various concerns, but in my view the serious dispute about antidepressant efficacy has a limited focus. Do they work for the core symptoms (such as despair, low energy and feelings of worthlessness) of isolated episodes of mild or moderate depression? The claim that antidepressants do nothing for this common condition — that they are merely placebos with side effects — is based on studies that have probably received more ink than they deserve.

The most widely publicized debunking research — the basis for the Newsweek and New York Review pieces — is drawn from data submitted to the Food and Drug Administration in the late 1980s and the 1990s by companies seeking approval for new drugs. This research led to its share of scandal when a study in The New England Journal of Medicine found that the trials had been published selectively. Papers showing that antidepressants work had found their way into print; unfavorable findings had not.

In his book “The Emperor’s New Drugs: Exploding the Antidepressant Myth,” Dr. Kirsch, a psychologist at the University of Hull in England, analyzed all the data. He found that while the drugs outperformed the placebos for mild and moderate depression, the benefits were small. The problem with the Kirsch analysis — and none of the major press reports considered this shortcoming — is that the F.D.A. material is ill suited to answer questions about mild depression.

As a condition for drug approval, the F.D.A. requires drug companies to demonstrate a medicine’s efficacy in at least two trials. Trials in which neither the new drug nor an older, established drug is distinguishable from a placebo are deemed “failed” and are disregarded or weighed lightly in the evaluation. Consequently, companies rushing to get medications to market have had an incentive to run quick, sloppy trials.

Often subjects who don’t really have depression are included — and (no surprise) weeks down the road they are not depressed. People may exaggerate their symptoms to get free care or incentive payments offered in trials. Other, perfectly honest subjects participate when they are at their worst and then spontaneously return to their usual, lower, level of depression.

THIS improvement may have nothing to do with faith in dummy pills; it is an artifact of the recruitment process. Still, the recoveries are called “placebo responses,” and in the F.D.A. data they have been steadily on the rise. In some studies, 40 percent of subjects not receiving medication get better.

http://www.nytimes.com/2011/07/10/opinion/sunday/10antidepressants.html?hpw