According to a report in today's PLos Medicine, a group of scientists who carried out a meta-analysis of the efficacy of Prozac and other selective serotonin re-update inhibitor (SSRI) medications used to treat depression found that there was no clinically significant benefit to any except the most deeply depressed patient. Even for the profoundly depressed, the difference in reaction between Prozac and the like versus a placebo is that the patients reacted less to the placebo, not more to the SSRI.

In 2005, Zoloft sales topped $3 billion. In 2006, Prozac sales reached almost half a billion dollars. Other SSRI drugs include Celexa, Lexapro, and Paxil as well as newer drugs such as Effexor, which works on both serotonin and norepinephrine.

To the degree that an antidepressant's effectiveness is aided by the patient's belief that it works, studies such as this serve to undermine that placebo effect. Given the strong motivation for drug companies to sell such products, the desperate need that the clinically depressed have, and the desire of physicians to provide relief, I can see how we might have all willingly embraced what now seems to have been a mass delusion: That these drugs help patients.

Man, that makes me blue.