title: Seeing is believing: Impact of social modeling on placebo and nocebo responding.
abstract: OBJECTIVE
  This study investigated the impact of the social modeling of side effects following placebo medication ingestion on the nocebo and placebo effect. It also investigated whether medication branding (brand or generic labeling) moderated social modeling effects.
  
  
  METHODS
  Eighty-two university students took part in the study which was purportedly investigating the impact of fast-acting beta-blocker medications (actually placebos) on preexamination anxiety. After taking the medication, participants were randomized to either witness a female confederate report experiencing side effects or no side effects after taking the same medication. Differences in symptom reporting, blood pressure, heart rate, and anxiety were assessed between the social modeling of side effects and no modeling groups.
  
  
  RESULTS
  Seeing a female confederate report side effects reduced the placebo effect in systolic (p = .009) and diastolic blood pressure (p = .033). Seeing a female confederate report side effects also increased both total reported symptoms (mean [SE] 7.35 [.54] vs. 5.16 [0.53] p = .005) and symptoms attributed to the medication (5.27 [0.60] vs. 3.04 [0.59] p = .01), although the effect on symptoms was only seen in female participants. Females who saw the confederate report side effects reported approximately twice the number of symptoms as those in the no modeling group. Social modeling did not affect heart rate or anxiety. Medication branding did not influence placebo or nocebo outcomes.
  
  
  CONCLUSIONS
  The social modeling of symptoms can substantially reduce or eliminate the placebo effect. Viewing a female confederate display symptoms after taking the same medication increases symptom reporting in females.
authors.affiliation: Department of Psychological Medicine.
authors.forename: Kate
authors.initials: K
authors.lastname: Faasse
authors.affiliation: Department of Psychological Medicine.
authors.forename: Andrew
authors.initials: A
authors.lastname: Grey
authors.affiliation: Department of Psychological Medicine.
authors.forename: Rachel
authors.initials: R
authors.lastname: Jordan
authors.affiliation: Department of Psychological Medicine.
authors.forename: Stacie
authors.initials: S
authors.lastname: Garland
authors.affiliation: Department of Psychological Medicine.
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Petrie
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000328:Adult; D001007:Anxiety / Q000453:epidemiology / Q000523:psychology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D003469:Culture; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D064786:Nocebo Effect; D015990:Placebo Effect; D012919:Social Behavior; D055815:Young Adult
chemical_list: D000319:Adrenergic beta-Antagonists