When people believe a medicine is expensive, they may show a greater response to it.
Researchers told 49 volunteers that they were testing two anti-itch creams — one that was costly, and one cheap — that contained the same ingredient known to reduce itch, but that the ingredient sometimes increased sensitivity to heat.
Then they showed them the two medicines, one in an expensive-looking brand-name box with fancy lettering, the other in a plain generic-looking container. They did not tell them that neither cream contained any medicine, and that both contained only the same inert ingredient.
They randomly assigned them to try either the expensive or cheap cream. All participants knew which cream they were using. The study is in Science.
When exposed to heat, the volunteers using the expensive cream felt consistently more pain than those using the cheap one, and the effect increased over time. Using fMRI brain scans, researchers were able to show exactly which parts of the brain were involved in modifying how price information affects pain.
“These expectations that patients have matter,” said the lead author, Alexandra Tinnermann, a doctoral candidate at the University Medical Center in Hamburg, Germany. “This is something doctors should be aware of and make use of to create positive expectations and reduce negative ones.”