BBC - Future - The contagious thought that could kill you

Over the last 10 years, doctors have shown that this nocebo effect – Latin for “I will harm” – is very common. Reviewing the literature, Mitsikostas has so far documented strong nocebo effects in many treatments for headache, multiple sclerosis, and depression. In trials for Parkinson’s disease, as many as 65% report adverse events as a result of their placebo. “And around one out of 10 treated will drop out of a trial because of nocebo, which is pretty high,” he says.

via www.bbc.com

This BBC Future feature is pretty cool.