Nocebo effect

“Placebo side effects occur when expectations of healing produce sickness, however minor; a positive expectation has a negative outcome. For example, a rash that occurs following administration of a placebo remedy may be a placebo side effect. . . . In the nocebo phenomenon, however, the subject expects sickness to be the outcome, i.e., the expectation is a negative one. . . . [In one study] 80 percent of hospitalized patients given sugar water and told that it was an emetic subsequently vomited” (Hahn, 57).