Trauma and pain sensitization in youth with chronic pain

INTRODUCTION: Chronic pain (pain lasting ≥3 months) co-occurs with internalizing mental health issues, such as posttraumatic stress symptoms (PTSS), at high rates in youth. The mechanisms underlying these relationships remain unclear. Posttraumatic stress symptoms, including re-experiencing (eg, intrusive memories), alterations in cognition and mood, hyperarousal, and avoidance could lead to altered neuronal processing, pain sensitization, and greater reports of pain. However, the relationships between PTSS and pain sensitization in youth with chronic pain are not known. METHODS: Youth (n = 165) aged 10 to 18 years were recruited from outpatient multidisciplinary chronic pain programs. Symptoms of PTSS were assessed using psychometrically sound questionnaires. Youth also underwent a cold-pressor task, the most commonly used experimental pain induction technique. During this task, they reported on their expected pain, actual pain intensity, and pre- and post-state pain catastrophizing. Their pain threshold was recorded. A multivariate general linear model was used to examine the relationships between PTSS, ratings of pain intensity, state pain catastrophizing, and pain threshold, controlling for age, gender, ethnicity, anxiety, and depressive symptoms. RESULTS: Higher PTSS were associated with greater pain thresholds (P = 0.03) and higher pre- and post-state pain catastrophizing (P ≤ 0.05). CONCLUSIONS: Individuals with higher PTSS may avoid or dissociate from pain-inducing stimuli, thus leading to higher pain thresholds. However, individuals with higher PTSS also tend to catastrophize prior to and following exposure to pain. Avoidant and pain catastrophizing behaviors may serve to perpetuate chronic pain conditions. Future research is needed to determine how PTSS are related to pain sensitization prior to the development of chronic pain in at-risk youth.