Unexplained placebo effect

Name(s): 
Nocebo effect
Negative placebo phenomenon
Nature 
The placebo effect in medicine has long been recognized: ill people improve because they believe they will. Recent studies have supported the opposite, or nocebo, effect: people become ill because they believe they will. Researchers point out that the relief or suffering of symptoms caused by the patient's beliefs are as real as those produced by external factors.
Type 
(J) Problems under consideration