What makes us sicker? An experimental study on non-specific adverse drug effects

Abstract

Effects of the colour of curatives, of previous experiences and expectations, and of personality variables upon the generation of non-specific adverse (nocebo) effects of drugs were studied in a double-blind, randomized experiment. Thirty-eight female undergraduate students completed questionnaires (experiences, expectancies, state anxiety (STAI-S), dispositional optimism (LOT-R), somatosensory amplification (SSAS), somatic symptoms (PHQ-15)), then randomly ingested a white or red NSAID tablet (200-mg ibuprofen), and monitored themselves for 10 min for symptoms. According to a regression analysis, predictors of experienced symptoms were personal experiences with and expectations of side effects, and SSAS and PHQ-15 scores. Regarding the 14 monitored symptoms, significant differences between red and white tablets were found in five cases (irritability/agitation, palpitation vs. drowsiness, blurred vision, heartburn). Better understanding of personality and situational factors causing nocebo effects could help to identify and to avoid them.