Placebo, price and pain relief

The medical profession has long debated the extent and value of the placebo effect - defined variously across a selection of web sites that I visited tonight as “the measurable, observable, or felt improvement in health or behavior not attributable to a medication or treatment that has been administered.” or “when a person is successfully treated by a dummy drug just because they believe it works.” Can enthusiastic doctors actively promoting dummy drugs have a greater effect on their patients purely on account of their passion and support for the drug? And what happens if patients are told something prior to taking a treatment about the price of a particular medicine?

A report in Science Daily today covers a letter from Dan Ariely (author of Predictably Irrational) whose team of collaborators have come up with some challenging research on the effects of price on the subjective rating of pain for people involved in a series of experiments:

“Ariely and a team of collaborators at the Massachusetts Institute of Technology used a standard protocol for administering light electric shock to participants’ wrists to measure their subjective rating of pain. The 82 study subjects were tested before getting the placebo and after. Half the participants were given a brochure describing the pill as a newly-approved pain-killer which cost $2.50 per dose and half were given a brochure describing it as marked down to 10 cents, without saying why. In the full-price group, 85 percent of subjects experienced a reduction in pain after taking the placebo. In the low-price group, 61 percent said the pain was less.”

So patients’ perception of the likely pain-killing properties of the drug might well have been anchored and influenced by prior knowledge about the market price. A similar outcome perhaps to perceived benefit and utility from drinking wine of varying price. People very often take their cue from the market price of something ..... if it is cheap there is a reason….

Surely the placebo effect must have something to do with a natural chemical reaction in the brain such that the expectation of receiving a treatment releases endomorphins into the bloodstream which might act as a natural painfiller or palliative - perhaps not dissimilar to the endomorphin release immediately you have finished a period of physical exercise?