Whether the “chemical imbalance” theory is true or not, the real question is, Do antidepressants work better than placebos? Psychologist Irving Kirsch, one of the authors reviewed by Angell, used the Freedom of Information Act to obtain drug companies’ records of their negative studies from the FDA. Unlike the positive results, negative results are normally not published. (Incredibly to this writer, negative results are considered proprietary and therefore confidential.) Taking both positive and negative results into consideration, Kirsch discovered that six popular drugs — Prozac, Paxil, Zoloft, Celexa, Serzone, and Effexor — scored unimpressively when compared with placebos. Yet, as Angell writes, “because the positive studies were extensively publicized, while the negative ones were hidden, the public and the medical profession came to believe that these drugs were highly effective antidepressants.” It gets more surreal. When depressed patients were prescribed drugs such as opiates, sedatives, stimulants and even herbal remedies, Kirsch and others found their symptoms were relieved to about the same degree as with SSRI-type antidepressants.
I first took a close look at treatments for mental illness 15 years ago while researching an article for Scientific American. At the time, sales of a new class of antidepressants, selective serotonin reuptake inhibitors, or SSRI’s, were booming. The first SSRI, Prozac, had quickly become the most widely prescribed drug in the world. Many psychiatrists, notably Peter D. Kramer, author of the best seller Listening to Prozac, touted SSRI’s as a revolutionary advance in the treatment of mental illness. Prozac, Kramer said in a phrase that I hope now haunts him, could make patients “better than well.”
Clinical trials told a different story. SSRI’s are no more effective than two older classes of antidepressants, tricyclics and monoamine oxidase inhibitors. What was even more surprising to me—given the rave reviews Prozac had received from Kramer and others—was that antidepressants as a whole were not more effective than so-called talking cures, whether cognitive behavioral therapy or even old-fashioned Freudian psychoanalysis. According to some investigators, treatments for depression and other common ailments work—if they do work—by harnessing the placebo effect, the tendency of a patient’s expectation of improvement to become self-fulfilling. I titled my article “Why Freud Isn’t Dead.” Far from defending psychoanalysis, my point was that psychiatry has made disturbingly little progress since the heyday of Freudian theory.