Altered Pain Perception and Fear-Learning Deficits in Subjects With Posttraumatic Stress Disorder

Josef Jenewein; Jeannine Erni; Hanspeter Moergeli; Christian Grillon; Sonja Schumacher; Christoph Mueller-Pfeiffer; Katayun Hassanpour; Annina Seiler; Lutz Wittmann; Ulrich Schnyder; Gregor Hasler

doi:10.1016/j.jpain.2016.09.002

Altered Pain Perception and Fear-Learning Deficits in Subjects With Posttraumatic Stress Disorder

J Pain. 2016 Dec;17(12):1325-1333. doi: 10.1016/j.jpain.2016.09.002. Epub 2016 Sep 15.

Affiliations

¹ Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland. Electronic address: josef.jenewein@usz.ch.
² Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
³ Mood and Anxiety Disorders Program, NIMH Intramural Research Program, Bethesda, Maryland.
⁴ International Psychoanalytic University, Berlin, Germany.
⁵ University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.

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.

Perspective: 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.

Keywords: Anxiety; chronic pain; fear; fear-learning; post-traumatic stress disorder.

MeSH terms

Adolescent
Adult
Aged
Chronic Pain / etiology*
Chronic Pain / psychology
Conditioning, Classical*
Fear / psychology*
Female
Humans
Learning Disabilities / epidemiology
Learning Disabilities / etiology*
Male
Middle Aged
Pain Perception / physiology*
Pain Threshold / physiology
Physical Stimulation / adverse effects
Psychometrics
Stress Disorders, Post-Traumatic / complications*
Stress Disorders, Post-Traumatic / epidemiology
Stress Disorders, Post-Traumatic / psychology*
Young Adult

Grants and funding

Z01 MH002798-07/Intramural NIH HHS/United States