title: Individual modulation of pain sensitivity under stress.
abstract: OBJECTIVE
  Stress has a strong influence on pain sensitivity. However, the direction of this influence is unclear. Recent studies reported both decreased and increased pain sensitivities under stress, and one hypothesis is that interindividual differences account for these differences. The aim of our study was to investigate the effect of stress on individual pain sensitivity in a relatively large female sample.
  
  
  METHODS
  Eighty female participants were included. Pain thresholds and temporal summation of pain were tested before and after stress, which was induced by the Mannheim Multicomponent Stress Test. In an independent sample of 20 women, correlation coefficients between 0.45 and 0.89 indicated relatively high test-retest reliability for pain measurements.
  
  
  RESULTS
  On average, there were significant differences between pain thresholds under non-stress and stress conditions, indicating an increased sensitivity to pain under stress. No significant differences between non-stress and stress conditions were found for temporal summation of pain. On an individual basis, both decreased and increased pain sensitivities under stress conditions based on Jacobson's criteria for reliable change were observed. Furthermore, we found significant negative associations between pain sensitivity under non-stress conditions and individual change of pain sensitivity under stress. Participants with relatively high pain sensitivity under non-stress conditions became less sensitive under stress and vice versa.
  
  
  CONCLUSIONS
  These findings support the view that pain sensitivity under stress shows large interindividual variability, and point to a possible dichotomy of altered pain sensitivity under stress.
authors.affiliation: Department of Psychosomatic Medicine and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany. tatyana.reinhardt@zi-mannheim.de
authors.forename: Tatyana
authors.initials: T
authors.lastname: Reinhardt
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Kleindienst
authors.forename: Rolf-Detlef
authors.initials: RD
authors.lastname: Treede
authors.forename: Martin
authors.initials: M
authors.lastname: Bohus
authors.forename: Christian
authors.initials: C
authors.lastname: Schmahl
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D010146:Pain / Q000175:diagnosis* / Q000503:physiopathology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D013315:Stress, Psychological / Q000503:physiopathology*; D055815:Young Adult