The pain of PTSD: integrating persistent or chronic pain within emotional processing theory of posttraumatic stress disorder

Abstract

Background: Posttraumatic stress disorder (PTSD) and chronic pain are devastating conditions that often co-occur. Current understanding of comorbid PTSD and chronic pain is limited, and treatment options are undereffective.Objective: This paper presents a theoretical basis for conceptualising chronic pain symptoms within Emotional Processing Theory (EPT), the foundation for Prolonged Exposure (PE), an effective treatment for PTSD. EPT conceptualises the development and treatment of PTSD using a trauma structure that strongly overlaps with pain's neurobiology.Method: This paper proposes a model of shared aetiology and treatment of comorbid PTSD and chronic pain, emphasising these shared neurobiological underpinnings. Discussion details how the comorbidity is maintained through parallel avoidance processes focused on: (1) trauma memories and reminders in PTSD preventing reduction of negative affect (extinction) and inhibitory learning, and (2) physical pain in chronic pain fuelling increased pain and reduced function.Results: A conceptualisation is presented on how PTSD and chronic pain symptomology can be addressed within the EPT framework, increasing the confidence of providers and patients while addressing an important gap in the literature. Finally, recommendations for providers using PE with patients with PTSD and pain are provided including a case example and treatment plan based on real patients.Conclusions: This model provides a clinically useful understanding of the underlying neurobiology for the co-occurrence of PTSD and chronic pain and offers direction for future research.

Keywords: PTSD; TEPT; case vignette; chronic pain; comorbidity; comorbilidad; dolor crónico; emotional processing theory; neurobiology; neurobiología; teoría de procesamiento emocional; tratamiento; treatment.

Figure 1.

a. A schematic representation of a trauma memory network following a motor vehicle collision in a patient with PTSD-Pain prior to receiving treatment. This patient’s memory holds a ‘trauma structure,’ linking stimuli, response, and meaning elements together. Stimulus elements may include people, places, or situations that were present at the time of the trauma. In this example, stimulus elements can be the interstate, street signs, experiencing back discomfort, or the act of riding a motorcycle. Response elements may include physiological reactions and behaviours that occurred at the time of the trauma. In this example, response elements can be PTSD symptoms, the sensory experience or unpleasantness of pain, and the behaviours to reduce motorcycle speed or exit the interstate. Meaning-making elements may include thoughts about what this traumatic event means to the survivor or the world. Meaning-making thoughts can include ‘I can’t control anything,’ ‘I am incompetent,’ ‘the crash is my fault’, or ‘the world is dangerous.’ While some elements are connected via helpful associations (i.e. reflecting danger in the current environment), other elements are connected via unhelpful associations and reflect PTSD-pain symptomology (i.e. reflecting danger at the time of the trauma/pain, rather than their current danger risk). The solid line connections represent these helpful connections. For instance, the connection between danger and a motorcycle accident reflects a real threat in the current environment and is a helpful connection. The dotted line connections represent unhelpful connections or connections that overestimate the current risk in the environment. For example, the connection between incompetence and exiting the highway is not helpful, because exiting the highway is not related to incompetence.

Figure 1.

a. A schematic representation of a trauma memory network following a motor vehicle collision in a patient with PTSD-Pain prior to receiving treatment. This patient’s memory holds a ‘trauma structure,’ linking stimuli, response, and meaning elements together. Stimulus elements may include people, places, or situations that were present at the time of the trauma. In this example, stimulus elements can be the interstate, street signs, experiencing back discomfort, or the act of riding a motorcycle. Response elements may include physiological reactions and behaviours that occurred at the time of the trauma. In this example, response elements can be PTSD symptoms, the sensory experience or unpleasantness of pain, and the behaviours to reduce motorcycle speed or exit the interstate. Meaning-making elements may include thoughts about what this traumatic event means to the survivor or the world. Meaning-making thoughts can include ‘I can’t control anything,’ ‘I am incompetent,’ ‘the crash is my fault’, or ‘the world is dangerous.’ While some elements are connected via helpful associations (i.e. reflecting danger in the current environment), other elements are connected via unhelpful associations and reflect PTSD-pain symptomology (i.e. reflecting danger at the time of the trauma/pain, rather than their current danger risk). The solid line connections represent these helpful connections. For instance, the connection between danger and a motorcycle accident reflects a real threat in the current environment and is a helpful connection. The dotted line connections represent unhelpful connections or connections that overestimate the current risk in the environment. For example, the connection between incompetence and exiting the highway is not helpful, because exiting the highway is not related to incompetence.

Figure 1.

a. A schematic representation of a trauma memory network following a motor vehicle collision in a patient with PTSD-Pain prior to receiving treatment. This patient’s memory holds a ‘trauma structure,’ linking stimuli, response, and meaning elements together. Stimulus elements may include people, places, or situations that were present at the time of the trauma. In this example, stimulus elements can be the interstate, street signs, experiencing back discomfort, or the act of riding a motorcycle. Response elements may include physiological reactions and behaviours that occurred at the time of the trauma. In this example, response elements can be PTSD symptoms, the sensory experience or unpleasantness of pain, and the behaviours to reduce motorcycle speed or exit the interstate. Meaning-making elements may include thoughts about what this traumatic event means to the survivor or the world. Meaning-making thoughts can include ‘I can’t control anything,’ ‘I am incompetent,’ ‘the crash is my fault’, or ‘the world is dangerous.’ While some elements are connected via helpful associations (i.e. reflecting danger in the current environment), other elements are connected via unhelpful associations and reflect PTSD-pain symptomology (i.e. reflecting danger at the time of the trauma/pain, rather than their current danger risk). The solid line connections represent these helpful connections. For instance, the connection between danger and a motorcycle accident reflects a real threat in the current environment and is a helpful connection. The dotted line connections represent unhelpful connections or connections that overestimate the current risk in the environment. For example, the connection between incompetence and exiting the highway is not helpful, because exiting the highway is not related to incompetence.

Figure 2.

The descending pain modulation system (adapted from (Martucci et al., 2014)). The spinal pathway from a noxious stimulus (depicted by a green circle outside of the spinal cord) travelling via Aδ and C nociceptive fibres within the dorsal horn of the spinal cord and relayed via the subcortical structures to the cortical structures. This figure depicts the neural pathways that correspond to the gate control theory of chronic pain and are targeted in Cognitive Behavioral Therapy for Chronic Pain. Illustration by Bona Kim; used with permission from ©Emory University. Abbreviations: ACC – anterior cingulate cortex, DLPT – dorsolateral pontine tegmentum, RVM – rostroventral medulla.

Figure 3.

Summary of the main neural pathways implicated in both PTSD and pain processing based on prior literature. The multiple cortical and subcortical structures involved in PTSD are depicted in red (Figure 3a; adapted from (Rauch et al., 2015)), and pain is depicted in blue (Figure 3b; adapted from (Martucci & Mackey, 2018)). The neural regions depicted in purple showcases the overlapping regions implicated in both PTSD and pain (fully combined in Figure 3c). These figures combine findings from previously segregated literature into one clear overlapping figure and highlight the overlapping neuroanatomy within PTSD and chronic pain conditions. Illustration by Bona Kim; used with permission from ©Emory University. Abbreviations: ACC – anterior cingulate cortex, AMG – amygdala, CC – cingulate cortex, HPC – hippocampus, INS – insula, LC – locus coeruleus, M1 – primary motor cortex, OFC – orbitofrontal cortex, PAG – periaqueductal grey, PFC – prefrontal cortex; RVM – rostroventral medulla, SMA – supplementary motor area, S1 – primary somatosensory cortex, S2 – secondary somatosensory cortex; TPJ – temporal parietal junction; Th – thalamus.

Figure 4.

A visual depiction of the components of Prolonged Exposure and Exposure Based CBT for Chronic Pain components that are complementary and a proposed integration strategy. PE content elements (Owens & Fett, 2019), exposure therapy for pain elements (Goldstein et al., ; Schnurr et al., 2022).