The Link Between Exposure to Traumatic Stress and Chronic Pain: The Mediation Effect of Hyperarousal Is Moderated by...

Posttraumatic stress disorder (PTSD) is highly comorbid with chronic pain. Yet, the effects of PTSD's seemingly opposing characteristics-hyperarousal and dissociation-on chronic pain are unclear. This study examined a moderated mediation model, accordingly (a) traumatic stress is associated with higher risk for chronic pain, through the mediation of hyperarousal, and (b) sensitivity to pain traumatization amplifies this association. Study 1 examined the moderated mediation model among a community sample, and Study 2 examined the moderation effect among PTSD outpatients.

This two-part cross-sectional study included a large community sample (N = 482; Study 1) and 47 PTSD outpatients (Study 2). Participants completed questionnaires assessing traumatic stress, hyperarousal, dissociation, sensitivity to pain traumatization, and chronic pain.

Traumatic stress in the community sample was associated with chronic pain presence, through the mediation of hyperarousal, yet this effect was significant only among individuals with high levels of sensitivity to pain traumatization (p < 0.001; Study 1). Similarly, hyperarousal among PTSD outpatients was associated with chronic pain presence only among those with moderate (p = 0.009) or high levels of sensitivity to pain traumatization (p = 0.009; Study 2). In both studies, dissociation was not associated with chronic pain presence.

Posttraumatic hyperarousal is associated with a higher risk for chronic pain, and this association is enhanced by sensitivity to pain traumatization. Screening for these traits in trauma-exposed individuals can help identify those at greater risk for chronic pain. Interventions for reducing hyperarousal may be valuable for mitigating chronic pain in high-sensitivity to pain traumatization individuals.

The findings of the current study suggest that the explanatory mechanism underlying the comorbidity of PTSD and chronic pain involves an interplay between hyperarousal and sensitivity to pain traumatization. Consequently, these factors may represent key targets for preventive or therapeutic interventions among survivors of traumatic events.