It always amazes me how people can speak with confidence about the placebo effect. Just what kind of phenomenon is it? Is it actually a manisfestion of self-organisation, of the biological ability to self-heal? If so, isn’t it something we should try to understand in order to maximise it?
Instead, placebo is frequently presented as “nothing”. The assumption is that a “placebo response” is not a “real” or “effective” response, and when used in randomised controlled trials, it is equated with doing nothing. In other words, if a treatment cannot demonstrate a statistically greater effect than a “placebo” it is considered to be “ineffective”. But is that true? Irving Kirsch has shown very clearly that “placebo” and “doing nothing” are far from the same, so it is illogical to argue that a treatment which produces a strong “placebo” response is “ineffective”.
Now here’s another interesting angle on the debate. A paper published in the Annals of Medicine about use of placebos in clinical trials points out that less than 10% of trials give any information about the make-up or content of the “placebo” used in the trial. Is this important? Well, they argue, yes, because sometimes the ingredients in the “placebo” produce a negative effect, and sometimes a positive one, but if we don’t know what was actually used, how can we make sense of the results?
This conclusion is fascinating –
“there isn’t anything actually known to be physiologically inert. On top of that, there are no regulations about what goes into placebos, and what is in them is often determined by the makers of the drug being studied, who have a vested interest in the outcome. And there has been no expectation that placebos’ composition be disclosed. At least then readers of the study might make up their own mind about whether the ingredients in the placebo might affect the interpretation of the study.”