メディエイゴ

A 10-cent pill doesn't kill pain as well as a $2.50 pill, even when they are identical(1) placebos(2), according to(3) a provocative(4) study by Dan Ariely, a behavioral economist(5) at Duke University.

"Physicians want to think it's the medicine and not their enthusiasm(6) about a particular drug that makes a drug more therapeutically(7) effective(8), but now we really have to worry about the nuances(9) of interaction(10) between patients and physicians(11)," said Ariely, whose findings appear as a letter in the March 5 edition of the Journal of the American Medical Association.

Ariely and a team of collaborators(12) at the Massachusetts Institute(13) of Technology used a standard protocol(14) for administering(15) light electric shock(16) to participants’(17) wrists(18) to measure their subjective(19) rating of pain. The 82 study subjects(20) were tested before getting the placebo and after. Half the participants were given a brochure(21) describing the pill(22) as a newly-approved(23) pain-killer(24) which cost $2.50 per dose(25) and half were given a brochure describing it as marked down(26) to 10 cents, without saying why.

In the full-price(27) group, 85 percent of subjects experienced a reduction(28) in pain after taking the placebo. In the low-price group, 61 percent said the pain was less.

The finding, from a relatively small and simplified(29) experiment, points to(30) a host of(31) larger questions, Ariely said.

The results fit with(32) existing data about how people perceive(33) quality and how they anticipate(34) therapeutic effects(35), he said. But what's interesting is the combination of the price-sensitive(36) consumer expectation(37) with the well-known placebo effect(38) of being told a pill works.