Dan Ariely, en adfærdsøkonom ved Duke Universitet har lavet et tankevækkende forsøg:

To grupper blev givet identisk placebo, den ene fik at vide, at det var en dyr smertestillende medicin (2,5$ per pille,) den anden gruppe fik at vide, det var en billig (10 cents per pille) smertestillende medicin.

I gruppen med den dyre "medicin" meldte 85 procent om smertenedsættelse, men kun 61 procent i gruppen med den billige "medicin" meldte om smertenedsættelse.

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

Costly placebo works better than cheap one - A 10-cent pill doesn't kill pain as well as a $2.50 pill, even when they are identical placebos, according to a provocative study by Dan Ariely, a behavioral economist at Duke University. [Eureka Alert]