IT used to be thought of as just a manipulation, a mind-trick. Doctors wore white coats, spoke in soothing tones, exuding confidence and medical know-how, and if they told you a pill would make you better, it would. By the time you found out it was just a sugar pill, you were feeling great, so who cares? The placebo effect works.
Or does it? Recent experiments suggest things are a lot more complicated than that. Some prescription drugs that were judged to perform “better than placebo” in clinical trials don’t work unless you know you’re taking them. Where does that leave the gold standard of medicine, the placebo-controlled clinical trial? Looking slightly shaky, at the very least.
It gets worse. I went to the labs of the leading placebo researchers in Turin and subjected myself to some experimentation. It turns out, to the researchers’ surprise, that you can succumb to placebo even when you know you’re being fooled. However, many of the claims of the power of the placebo effect might be overstated: recent research also suggests that the placebo effect does much less than it’s generally given credit for. In most cases its effects are simply not clinically useful. Confused? Then don’t think about the neuroscience experiments that show the biochemical side of placebo – it has a real, chemical effect on the brain that researchers can learn to manipulate.
It turns out that there is no such thing as a straightforward placebo effect: there may be as many different effects as there are drugs, situations and people. In other words, it’s a bit like cosmology’s dark energy: something is going on, but no one has any idea what.