Irving Kirsch, best known for that 2008 meta-analysis allegedly showing that "Prozac doesn't work", has hit the headlines again.
This time it's a paper claiming that something does work. Actually Kirsch is only a minor author on the paper by Kaptchuck et al: Placebos without Deception.
In essence, they asked whether a placebo treatment - a dummy pill with no active ingredients - works even if you know that it's a placebo. Conventional wisdom would say no, because the placebo effect is driven by the patient's belief in the effectiveness of the pill.
Kaptchuck et al took 80 patients with Irritable Bowel Syndrome (IBS) and recruited them into a trial of "a novel mind-body management study of IBS". Half of the patients got no treatment at all. The other half got inert cellulose capsules, after having been told, truthfully, that the pills contained no active drugs but also having been ...
