Why some people respond to treatments that have no active ingredients in them may be down to their genes, a study in the journal PLoS ONE suggests.
The so-called “placebo effect” was examined in 104 patients with irritable bowel syndrome (IBS) in the US.
Those with a particular version of the COMT gene saw an improvement in their health after placebo acupuncture.
Ted Kaptchuk, director of the Program in Placebo Studies and Therapeutic Encounter at BIDMC, said: “We wanted to tease apart the different doses of placebo.
“We got an effect in individuals with this specific genetic signature for the general placebo, but an even bigger effect in the elaborate placebo where warmer care was given.
This will not be the turning point for understanding the placebo effect but it may help. As Professor Edzard Ernst said: “This is a fascinating but very preliminary result.” The study was small and only applied to this one disease. A previous study on a different condition showed a different response which suggests there is not just a single placebo response or mechanism, but many and various depending on specific factors.