Hypnosis and Placebo
While I was trawling through PubMed the other day looking for articles about hypnosis (a curious past-time I know) I was struck by several articles that made reference to hypnosis being effective in the same conditions that placebo was, often inflammatory conditions. Now this is, in part, true, in my experience. Inflammatory conditions or conditions in which inflammatory processes play a significant role ARE conditions that often respond well to both the placebo effect and to hypnosis. But the tendency in these articles was to therefore equate hypnosis with placebo. This is simply poor reasoning.
A placebo can been defined as “a substance or procedure… that is objectively without specific activity for the condition being treated”. It is known to have no effect in respect to the condition it is being given for. And yet it often has a significantly greater-than-chance positive treatment response compared to non-treatment when the patient is given a placebo instead of active treatment, when compared to a non-treatment group. Not unreasonably, the conclusion is that that the belief of the patient regarding the efficacy of the treatment they are given somehow stimulates a physiological response. Actually the effect can still be observed when the patient knowingly receives a placebo. And it isn’t always a positive effect. If the expectations of the recipient are that the inert substance can do harm, it can have negative effects, often referred to as nocebo. But all that is an aside.
The error is in equating hypnosis with placebo. Hypnosis may well trigger a placebo mechanism but that does not make it the same thing. Hypnosis, as a procedure, specifically focuses on changing a number of things, including the client’s beliefs about the condition, their relationship to it and their expectations regarding the outcome of their sessions. All these will, if pertinent to the session goals, will influence a placebo response so it is unsurprising that we see a similarity between placebo and hypnosis. But it does not make hypnosis a placebo.