People receiving an inert treatment believed they experienced more severe adverse side effects when the dummy drug was labeled as expensive, scientists report.
The researchers say brain regions responsible for higher-order cognition can influence primal pain sensing at the spinal level.
To study the neurological causes for the so-called nocebo effect (where people in clinical trials sometimes report negative side effects even though they received inactive substances), Alexandra Tinnermann and colleagues developed a new functional magnetic resonance imaging (fMRI) method for simultaneous activity measurements in the entire central pain system throughout the cortex, brainstem, and spinal cord.
For the nocebo treatment, the scientists enrolled 49 people in a trial for a supposed anti-itch cream that, in reality, contained no active ingredients.
All participants were told that increased pain sensitivity was a potential side effect for the inert cream, but some were informed that they were receiving an expensive ointment and others were led to believe that the lotion was cheap (the scientists even created two different packages for the balms, indicating high or low price).