Converging evidence suggests that the occurrence of unwanted adverse events during drug treatment is in part determined by nonpharmacological effects. For instance, the majority of unwanted adverse effects and symptoms reported by patients in clinical trials often are not caused by the medication, because unwanted adverse effects can also occur to a comparable degree in the placebo group of the study.1 Similarly, the switch from brand name to generic drugs with identical compounds is frequently associated with an increase in unwanted adverse effects and therefore could lead to treatment discontinuation. These examples highlight that patients’ expectations regarding adverse effects are important determinants of unwanted adverse effects during drug treatment.
Bingel U, For the Placebo Competence Team. Avoiding Nocebo Effects to Optimize Treatment Outcome. JAMA. 2014;312(7):693-694. doi:10.1001/jama.2014.8342