Pain sensitivity in posttraumatic stress disorder and other anxiety disorders: a preliminary case control study

BACKGROUND: Despite substantial research on the comorbidity of anxiety disorders including posttraumatic stress disorder (PTSD) and chronic pain, little is known about the mechanisms underlying these conditions that might be potentially similar. Evoked pain sensitivity is one factor that has been associated with several pain conditions which might also have relevance to anxiety disorders and PTSD. The aim of this preliminary study was to examine evoked pain sensitivity in PTSD compared to other anxiety disorders and in control participants. METHOD: The study used a cross-sectional case-control design in which participants completed a battery of questionnaires and structured interview and underwent cold pressor testing. RESULTS: Of 61 total participants, those in the PTSD (n =16) and other anxiety groups (n =12) endorsed significantly higher levels of psychological symptoms and poorer health functioning than control participants (n =33). The linear trend across baseline, threshold, and tolerance pain ratings from the cold pressor task significantly differed between participants with PTSD and the other anxiety and control groups suggesting lower pain sensitivity to a standardized stimulus of pain in individuals with PTSD. CONCLUSIONS: These findings are similar to some of the prior research and suggest that individuals with PTSD may exhibit lower cold pain sensitivity compared to those with other anxiety disorders. There is a need for future research to determine explanatory mechanisms.