Negative experiences can stop painkillers working
A patient's belief that a drug will not work can become a self fulfilling prophecy, according to researchers.
They showed the benefits of painkillers could be boosted or completely wiped out by manipulating expectations.
The study, published in Science Translational Medicine, also identifies the regions of the brain which are affected.
Experts said this could have important consequences for patient care and for testing new drugs.
Heat was applied to the legs of 22 patients, who were asked to report the level of pain on a scale of one to 100. They were also attached to an intravenous drip so drugs could be administered secretly.
http://www.bbc.co.uk/news/health-12480310