Nocebo vs Placebo Effects: Their Clinical Relevance

The placebo effect can be defined as any improvement of illnesses or reduction of subjective symptoms that result from interventions possessing no known physical effects. By contrast, the nocebo effect refers to undesirable symptoms or illnesses that follow interventions also lacking known physical effects. It may also play a role in chronic illnesses that lack objective confirmation. Both placebo and nocebo effects can be potent and must be understood by both practitioners and researchers for proper application in clinical medicine. Individual caregivers can apply these principles to modify results in the daily care of patients.