The Effect of Temporal Information on Placebo Analgesia and Nocebo Hyperalgesia. Issue 1 (January 2021)

• Record Type: Journal Article
• Authors: Camerone, Eleonora Maria; Piedimonte, Alessandro; Testa, Marco; Wiech, Katja; Vase, Lene; Zamfira, Denisa Adina; Benedetti, Fabrizio; Carlino, Elisa
• Is Part Of: Psychosomatic medicine. Volume 83:Issue 1(2021)
• Publication Date: 2021-01
• Subjects: placebo effect -- nocebo effect -- pain -- expectation -- ANOVA = analysis of variance -- BMI = body mass index -- N5 = nocebo 5 -- N15 = nocebo 15 -- N30 = nocebo 30 -- NE = no expectations -- NH = natural history -- NRS = Numerical Rating Scale -- P5 = placebo 5 -- P15 = placebo 15 -- P30 = placebo 30 -- SNK = Student-Newman-Keuls -- STAI I/STAI II = State-Trait Anxiety Inventory (I-II); Medicine, Psychosomatic -- Periodicals; 616.0805
• DOI: 10.1097/PSY.0000000000000882
• Languages: English
• ISSNs: 0033-3174

Abstract

ABSTRACT: Objective: Expectations are known to be key determinants of placebo and nocebo phenomena. In previous studies, verbal suggestions to induce such expectations have mainly focused on the direction and magnitude of the effect, whereas little is known about the influence of temporal information. Methods: Using an experimental placebo and nocebo design, we investigated whether information about the expected onset of a treatment effect modulates the start and time course of analgesic and hyperalgesic responses. Healthy volunteers ( n = 166) in three placebo and three nocebo groups were informed that the application of an (inert) cream would reduce (placebo groups) or amplify pain (nocebo groups) after 5, 15, or 30 minutes. Two control groups were also included (natural history and no expectations). Participants' pain intensity rating of electrical stimuli administered before and 10, 20, and 35 minutes after cream application was obtained. Results: Mixed-method analysis of variance showed a significant interaction between group and time ( F (12, 262) = 18.172, p < .001, pη 2 = 0.454), suggesting that pain variations differed across time points and between groups. Post hoc comparisons revealed that the placebo and nocebo groups began to show a significantly larger change in perceived pain intensity than the no-expectancy control group at the expected time point ( p < .05) but not earlier ( p > .05). Once triggered, the analgesic effect remained constant over the course of the experiment, whereas the hyperalgesic effect increased over time. Conclusions: Our results indicate that temporal suggestions can shape expectancy-related treatment effects, which, if used systematically, could open up new ways to optimize treatment outcome. Abstract : Supplemental digital content is available in the text.