Comorbid chronic pain and posttraumatic stress disorder across the lifespan: A review of theoretical models

Abstract

Chronic pain is often associated with functional, psychological, and social problems that can have a significant negative impact on a person's quality of life. Substantial literature currently exists documenting the relationship between chronic pain and commonly co-occurring disorders such as substance abuse (Brown et al., 1996), depression (Banks and Kerns, 1996), and anxiety disorders (Asmundson et al., 1996). Importantly, interest in the relationship between chronic pain and these disorders has expanded the field of pain research, has improved our understanding of how these conditions may interact with one another, and has contributed to improvements in pain management. Pain is often related to naturally occurring degenerative changes in the body that develop gradually over time; however, some pain conditions may develop secondary to injury related to traumatic life events such as motor vehicle accidents, occupational injuries, or military combat. This has led to a growing interest in the relationship between pain and Posttraumatic Stress Disorder (PTSD), as clinical practice and research indicate that the two disorders frequently co-occur and may interact in such a way as to negatively impact the course and outcome of treatment of either disorder. Several theoretical models and potential mechanisms have been proposed to explain the relationship between chronic pain and PTSD. Despite this recent interest in studying pain and PTSD, no empirical studies have been conducted to test theoretical models explaining the comorbidity of these two disorders, and no well-controlled studies have investigated the efficacy of tailoring treatments for individuals with these disorders. Such studies have the potential to advance theory development and improve treatment efficacy. The primary aim of this chapter is to provide a critical review and synthesis of the existing literature investigating the relationship between chronic pain and PTSD. The chapter begins with a presentation of the diagnostic criteria, prevalence, and theoretical models of chronic pain and PTSD. Research is then presented describing the co-occurrence of the two disorders, and several theoretical models are highlighted that may serve to explain the similar mechanisms by which these two disorders may be maintained. This chapter then addresses how comorbid chronic pain and PTSD may present differently in youth, with consideration of how theoretical models of the comorbidity of pain and PTSD may be modified to incorporate developmental factors. Furthermore, the chapter helps to explicate how the experience of comorbid chronic pain and PTSD can vary from childhood to adulthood. Finally, the chapter closes with a section on implications for treatment as well as a call for continued research to further refine the models reviewed.