title: Altered Pain Perception and Fear-Learning Deficits in Subjects With Posttraumatic Stress Disorder.
abstract: There is growing evidence that fear-learning abnormalities are involved in the development of posttraumatic stress disorder (PTSD) and chronic pain. More than 50% of PTSD patients suffer from chronic pain. This study aimed to examine the role of fear-learning deficits in the link between pain perception and PTSD. We included 19 subjects with PTSD and 21 age- and sex-matched healthy control subjects in a fear-conditioning experiment. The conditioned stimulus (CS) consisted of visual signs flashed upon a screen in front of each subject. The unconditioned stimulus was either a low or high temperature impulse delivered through a thermal contact thermode on the subjects' hand. A designation of 'CS-' was assigned to CS always followed by nonpainful low-temperature stimuli; a designation of 'CS+' was given to CS that were randomly followed by either a low or a more painful high temperature. Skin conductance was used as a physiological marker of fear. In healthy control subjects, CS+ induced more fear than CS-, and a low-temperature stimulus induced less subjective pain after CS- than after CS+. PTSD subjects failed to demonstrate such adaptive conditioning. Fear ratings after CS presentation were significantly higher in the PTSD group than in the control group. There were significant interaction effects between group and the type of CS on fear and pain ratings. Fear-learning deficits are a potentially promising, specific psychopathological factor in altered pain perception associated with PTSD. Deficits in safety learning may increase fear and, consequently, pain sensations. These findings may contribute to elucidating the pathogenesis behind the highly prevalent comorbidity that exists between PTSD and pain disorders, and to developing new treatments.
  
  
  
  This study provides new insights into the pathogenesis of chronic pain in patients with PTSD. The findings may help to develop new treatment strategies for this highly prevalent comorbidity in PTSD.
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland. Electronic address: josef.jenewein@usz.ch.
authors.forename: Josef
authors.initials: J
authors.lastname: Jenewein
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Jeannine
authors.initials: J
authors.lastname: Erni
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Moergeli
authors.affiliation: Mood and Anxiety Disorders Program, NIMH Intramural Research Program, Bethesda, Maryland.
authors.forename: Christian
authors.initials: C
authors.lastname: Grillon
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Sonja
authors.initials: S
authors.lastname: Schumacher
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Mueller-Pfeiffer
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Katayun
authors.initials: K
authors.lastname: Hassanpour
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Annina
authors.initials: A
authors.lastname: Seiler
authors.affiliation: International Psychoanalytic University, Berlin, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Wittmann
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schnyder
authors.affiliation: University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.
authors.forename: Gregor
authors.initials: G
authors.lastname: Hasler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D059350:Chronic Pain / Q000209:etiology* / Q000523:psychology; D003214:Conditioning, Classical; D005239:Fear / Q000523:psychology*; D005260:Female; D006801:Humans; D007859:Learning Disabilities / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D058748:Pain Perception / Q000502:physiology*; D017288:Pain Threshold / Q000502:physiology; D010812:Physical Stimulation / Q000009:adverse effects; D011594:Psychometrics; D013313:Stress Disorders, Post-Traumatic / Q000150:complications* / Q000453:epidemiology / Q000523:psychology*; D055815:Young Adult
keywords: Anxiety; chronic pain; fear; fear-learning; post-traumatic stress disorder