The Relationship Between Posttraumatic Stress Disorder and Chronic Pain in People Seeking Treatment for Chronic Pain: The Mediating Role of Psychological Flexibility

Objectives: The symptoms of Posttraumatic Stress Disorder (PTSD) and chronic pain are thought to interact to increase the severity and impact of both conditions, but the mechanisms by which they interact remain unclear. This study examines the relationship between PTSD and chronic pain and whether indices of psychological flexibility mediate the relationship between these two conditions. Methods: Standardized self-report measures of PTSD, pain severity, pain interference, depression, and psychological flexibility (pain-related acceptance, committed action, cognitive fusion, and values-based action) were obtained from 315 people seeking treatment for chronic pain who also reported at least one traumatic experience. Results: People seeking treatment for chronic pain reporting symptoms consistent with a current diagnosis of PTSD had significantly higher levels of pain severity, pain interference, depression, and cognitive fusion and lower levels of pain-related acceptance and committed action than those reporting symptoms below diagnostic threshold for PTSD. Pain-related acceptance, committed action, cognitive fusion and depression mediated the relationship between PTSD and pain severity/interference, with pain-related acceptance being the strongest mediator from the psychological flexibility model. Discussion: Processes from the psychological flexibility model were identified as mediators of the relationship between PTSD and chronic pain in people seeking treatment for chronic pain. The psychological flexibility model may be useful as an overarching model to help understand the relationship between PTSD and chronic pain. It is possible that targeting painrelated acceptance, committed action, and cognitive fusion (among other processes) in the treatment of chronic pain may produce corresponding improvements in comorbid symptoms of PTSD when these are present and may reduce impacts of PTSD on outcomes of chronic pain. Conversely, targeting of these processes in the treatment of PTSD may produce similar improvements for symptoms of chronic pain. Further research to evaluate these possibilities is needed.