A cross-sectional study of the prevalence and correlates of post-traumatic stress among people attending acceptance and commitment therapy for chronic pain

Objective Experiences of trauma are common among people with chronic pain, although estimates of comorbid post-traumatic stress vary widely across contexts. Acceptance and commitment therapy (ACT), which targets psychological flexibility to improve pain-related functioning, is increasingly delivered for people with pain. To inform treatment delivery, understanding of the prevalence and correlates of post-traumatic stress among those attending ACT-based treatment for pain is needed. This study aimed to identify the prevalence of post-traumatic stress and its associations with key pain-related outcomes and other relevant psychosocial factors at the start of an ACT-based treatment. Methods This was a cross-sectional study using data collected within routine clinical care at a speciality pain management service in the UK. Four hundred and fifty-one participants completed standardized self-report questionnaires of post-traumatic stress symptoms (PTSS), pain-related outcomes (pain intensity and interference, work and social adjustment, and depression symptoms), psychological flexibility/inflexibility, and stigma at the start of an interdisciplinary ACT-based treatment for chronic pain. Results Forty-seven percent of patients ( n = 213) reported a traumatic exposure and 30% of the sample reported clinically meaningful PTSS. Greater severity of PTSS and probable post-traumatic stress disorder (PTSD) were associated with significantly worse pain-related outcomes, psychological flexibility/inflexibility, and stigma in bivariate analyses. PTSS severity and probable PTSD showed significant unique associations with poorer pain outcomes in regression models controlling for covariates and psychological flexibility/inflexibility. Conclusions Post-traumatic stress is common among people engaging in ACT-based treatment for pain and associated with adverse pain outcomes. Trauma-informed practice is therefore important when providing ACT-based treatment for pain.