Link HT: John Goodman
Nocebos can even be fatal. In one classic example, women in the multi-decade Framingham Heart study who thought they were at risk for heart attacks were 3.7 times as likely to die of coronary conditions as women who didn't have such fears -- regardless of whether they smoked or had other risk factors.
Research deliberately causing nocebos has been limited (after all, it's kind of cruel). But in one 1960s test, when hospital patients were given sugar water and told it would make them vomit, 80% of them did.
Studies have also shown that patients forewarned about possible side effects are more likely to encounter them. In a study last year at the University of Turin, Italy, men taking finesteride for enlarged prostates who were informed that it could cause erectile dysfunction and decreased libido were three times as likely to experience such side effects as men who weren't told.
"People's expectations play a very important role in how they react to all medications," says Richard Kradin, a physician and psychoanalyst at Massachusetts General Hospital in Boston, and author of "The Placebo Response and the Power of Unconscious Healing." He notes that about 25% of patients who get completely inert placebos in clinical trials complain of side effects -- typically headaches, drowsiness and dizziness.