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Updated: May 21, 2026
An Experimental Paradigm for the Prediction of Post-Operative Pain (PPOP)
Published on: January 27, 2010
How positive and negative expectations shape the experience of visceral pain: an experimental pilot study in healthy
S Elsenbruch1, J Schmid, M Bäsler
1Institute of Medical Psychology & Behavioral Immunobiology, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany. sigrid.elsenbruch@uk-essen.de
Background:
In order to elucidate placebo and nocebo effects in visceral pain, we analyzed the effects of positive and negative expectations on rectal pain perception, rectal pain thresholds, state anxiety and cortisol responses in healthy women.
Methods:
Painful rectal distensions were delivered at baseline, following application of an inert substance combined with either positive instructions of pain relief (placebo group, N = 15), negative instructions of pain increase (nocebo group, N = 17), or neutral instructions (control, N = 15). Perceived pain intensity, unpleasantness/aversion and urge-to-defecate, state anxiety and serum cortisol were determined at baseline, immediately following group-specific instructions and on a second study day after the same instructions (test day). Rectal pain thresholds were determined at baseline and on the test day.
Key Results:
Whereas perceived pain intensity was significantly decreased in the placebo group, the nocebo group revealed significantly increased pain intensity ratings, along with significantly greater anticipatory anxiety on the test day (all P < 0.05 vs controls). Cortisol concentrations were significantly increased in the nocebo group following treatment but not on the test day.
Conclusions & Inferences:
The experience of abdominal pain can be experimentally increased or decreased by inducing positive or negative expectations. Nocebo effects involve a psychological stress response, characterized by increased anticipatory anxiety. These findings further underscore the role of cognitive and emotional factors in the experience of visceral pain, which has implications for the pathophysiology and treatment of patients with chronic abdominal complaints.
