Comorbid Chronic Pain and PTSD: An Update on Research and Treatment
Chronic pain and PTSD often interact to negatively impact the course of either disorder, requiring thoughtful assessment and reflexive, tailored treatments.By David Cosio, PhD, ABPP and Amy Demyan, PhD, RYT
The prevalence rate of chronic pain in the general US population ranges between 10% to 20%.1 Chronic pain has been found to commonly coexist with post-traumatic stress disorder (PTSD) symptoms. In the veteran population, the prevalence of PTSD has been found to be between 10% to 47% among those referred to a pain clinic2,3 or attending a multidisciplinary chronic pain center.4 Patients with comorbid chronic pain and PTSD have been found to endorse more negative belief-based and behavioral symptoms compared to patients with chronic pain only.3,5 They have also been found to be at greater risk for negative coping, such as with substance use.5
Together, these findings support the need for tailored treatment interventions for patients with comorbid chronic pain and PTSD. Consequentially, theory-supported treatment programs have evolved overtime to meet the unique needs of patients who suffer from this type of comorbidity.
Post-Traumatic Stress Disorder Defined
To understand the best treatment practices applied to comorbid chronic pain and PTSD, the utilization of the proper assessment of PTSD is crucial. The definition of PTSD has broadened since the release of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013.6 The diagnosis now includes traumatic events that were experienced directly, indirectly, witnessed by the individual, or experienced by a family member or friend.6 In addition to these experiences, the individual must also exhibit symptoms from four different clusters of symptoms:
- persistent negative alterations in cognitions and mood
PTSD can be diagnosed accurately by a trained mental health professional. The gold standard assessment is the Clinician Administered PTSD Scale for the DSM-5 (CAPS-5), which employs an interview with the patient about trauma and PTSD symptoms. PTSD has been found to affect 10% of women and 5% of men at some stage.7 However, the prevalence rates of PTSD in victims of trauma have been purported to approach 100%.8
Physical health problems (cardiovascular, headaches, diabetes, respiratory, gastrointestinal, and musculoskeletal) have been shown to be more common among individuals suffering from PTSD.9 Studies examining the prevalence of chronic pain in individuals with a primary diagnosis of PTSD have reported even higher co-prevalence rates. The rate of chronic pain in patients who suffer from PTSD is approximately double that of the general population.9 Pain is the most common physical complaint among patients who suffer from PTSD.10 Research has shown that anywhere from 60% to 80% of veterans with PTSD report that they have a chronic pain condition.11,12
Prevalence of Comorbid Pain and PTSD
When PTSD and chronic pain are considered together, the prevalence among returning veterans has been found to be 16.5%.13 Earlier studies reported a 1.7% prevalence of PTSD among chronic pain patients.14 However, in a more recent study, 47% of a sample of veterans with chronic pain met criteria for PTSD.3 Further, the prevalence of PTSD among injured workers referred to a rehabilitation program was found to be approximately 35%.15 Further, comorbid prevalence rates have been found to range between 30% to 50% among patients whose pain is secondary to a motor vehicle accident.16
Moreover, the prevalence of PTSD among hospitalized burn patients has been found to be approximately 45% at 12-months post injury.17 These comorbid conditions may interact in such a way as to negatively impact the course of either disorder,18 requiring thoughtful assessment and reflexive, tailored treatments.
Individuals with this comorbidity report health problems with increased functional impairment, greater frequency19 and higher pain ratings.5 Research indicates that patients with chronic pain related to trauma or PTSD experience more affective distress,20 higher levels of life interference,21 and greater disability22 than their counterparts without trauma or PTSD. They further report decreased occupational functioning, including more frequent absenteeism19 and greater loss of productivity.23 More importantly, they demonstrate higher rates of healthcare service utilization and increased healthcare costs.
Theories Behind Overlapping Chronic Pain and PTSD
There are several theories that may help explain the high rates of comorbid chronic pain and PTSD. For example, the theory ofshared vulnerability proposes that underlying mechanisms, such as anxiety sensitivity, are implicated in the comorbidity. Another theory, the mutual maintenance hypothesis, proposes that cognitive, affective, behavioral (eg, avoidance), and physiological symptoms of both disorders react in a synergistic way. Both chronic pain and PTSD share the clinical features of fear and avoidance, which may influence the development of each condition over time, may serve to maintain them, and may interact in ways that impact the outcome of either condition in a feedback loop.19
The fear-avoidance modelis generally acknowledged for diagnosing and understanding how humans adaptively and maladaptively react to fear.24 In the realm of chronic pain, the model describes how individuals develop chronic, musculoskeletal pain as a result of avoidant behavior based on fear.25 The fear-avoidance model states that negative appraisals about pain and its consequences, including catastrophic thoughts, can result in feelings of pain-related fear, avoidance of daily activities, and hypervigilance or over-monitoring of bodily sensations.26 As a result of this misinterpretation, the individual repeatedly avoids the pain-inducing activity and will likely overestimate any future pain from such activity. In turn, the avoidance response ultimately results in physical deconditioning, depression, disability from work, inability to participate in recreation, and incapacity for family activities.27 This perpetuates the pain experience as opposed to moving toward wellness. Once the avoidant behavior is no longer reinforced, the individual exits the positive feedback loop.28
There is evidence that fear-avoidance is closely related to increased pain, physical disability, and long-term sick leave in chronic pain patients.29 This does not mean that the patient is “faking it” or that “it’s all in their head.” Rather, it demonstrates the importance of the mind/body connection in symptom expression and the power of formerly learned coping strategies that were once functionally adaptive. However in avoidance coping, patients miss the opportunity to examine the untested hypothesis: Does avoidance really keep me safe? With support and guidance, providers can gently encourage small, slow gains.
According to this model, treatment recovery is facilitated when pain acceptance is promoted. Pain acceptance increases when an individual uses adaptive coping mechanisms while minimizing or neutralizing negative thoughts or beliefs about pain, and/or pain catastrophizing. This approach can be expanded to include PTSD and can provide a comprehensive explanatory framework for the conceptual, symptomatic, and behavioral overlap of the two conditions.30
Treatment Modalities for PTSD and Chronic Pain
There are three primary approaches to treating patients who present with both chronic pain and PTSD31:
- The parallel model
- The sequential model
- The combined or integrated multidisciplinary model
First, the parallel model treats each disorder at the same time but with separate medical teams who may or may not collaborate. As a result, the treatment teams may be operating from different philosophies of treatment without knowing it. Treatment using this model often leaves patients with little to no comprehensive help, as people are often not eligible for multiple services at the same time or there is not a provider who wants to take on the responsibility of both disorders.
Next, the sequential model is historically the most common framework of comorbid treatment. In this model of treatment, the patient is treated by two separate medical teams, with one treating one disorder and then the other team treating the other condition afterwards. This model may be problematic in that the untreated disorder may worsen the treated disorder. Also problematic is that treatment teams may disagree as to which disorder should be treated first. Furthermore, the patient may be left with an untreated disorder at times due to a lack of follow-through by providers and/or patients with the referral to the second medical team.
Lastly, the most promising framework is a combined, or integrated multidisciplinary model. The integrated model is relatively new, but it has been demonstrated as an effective method in many scientific studies. This treatment model helps patients recover by simultaneously offering treatment for comorbid disorders, treating both chronic pain and PTSD simultaneously in the same setting with providers working collaboratively and/or with providers who have expertise in both chronic pain and PTSD.
A multidisciplinary treatment approach to pain has been found to be the most effective method for patients with comorbid chronic pain and PTSD.4 Several of the more common causes of chronic pain include traumatic events; thus, it is not unusual for patients presenting with chronic pain to also describe significant levels of distress including PTSD.32 The multidisciplinary treatment model should emphasize helping patients draw links between the traumatic event and subsequent chronic pain and PTSD.
Psychotherapy has been found to be the most effective therapy for patients with comorbid chronic pain and PTSD. Cognitive-Behavioral Therapy (CBT) is a structured, time-limited, present-focused approach to psychotherapy that helps patients engage in an active coping process. The aim of the treatment is to change maladaptive thoughts and behaviors that serve to maintain and exacerbate the experience of both chronic pain and PTSD. Patients have demonstrated benefits from CBT techniques (exposure therapy, pacing, and activity scheduling) to alleviate both conditions.32,33 CBT interventions have been associated with significantly greater improvements in maladaptive coping responses to pain than wait-list controls.34 The current literature also reveals robust evidence that CBT is effective for PTSD.35 Not only can CBT help restructure maladaptive thinking, it can also assist with making unhealthy behaviors become more adaptive.
CBT Treatment Protocol for PTSD
When chronic pain and PTSD symptoms co-occur, it is likely that providers will need to modify treatment protocols accordingly.36 One such integrated protocol was developed by Otis & Keane in 2009 at the VA Boston Healthcare System.37 This therapist’s manual combines traditional CBT with cognitive processing therapy used in PTSD treatment and is divided into 12 60-minute sessions.
As outlined in Table I, the CBT protocol for PTSD begins by helping patients become aware of the links between chronic pain and PTSD symptoms. In addition, cognitive therapy strategies address attentional biases, challenge overestimation of probability and cost, reinforce positive pain self-efficacy beliefs, and challenge catastrophizing.32
Furthermore, the manual includes strategies aimed specifically at reducing anxiety sensitivity using interoceptive exposure. The protocol then aims to increase activity levels through the use of activity pacing and then ends focuses on reducing cognitive and behavioral avoidance through the use of in vivo and imaginal exposure surrounding specific belief systems. Some scholars have argued that concurrent treatment of chronic pain and PTSD that is underway in the veteran population may also be beneficial to nonmilitary/nonveteran populations.30
Practical Takeaways for Providers
Rates of comorbid chronic pain and PTSD vary across populations and settings. Patients with comorbid chronic pain and PTSD have been found to experience more severe symptoms, greater functional impairment and disability, and higher rates of catastrophizing compared to patients with chronic pain only. As a result, patients who suffer from this comorbidity are often undertreated with traditional treatment modalities. Empirically supported, theory-driven advancements in treatment offer evidence for the effectiveness of multidisciplinary treatment approaches using a psychotherapeutic, CBT framework.
Overall, pain and behavioral specialists should remember:
- Chronic pain and PTSD often co-occur in patients, requiring multidisciplinary treatment.
- Assessment of PTSD is important when treating chronic pain patients. The gold standard PTSD assessment is the Clinician Administered PTSD Scale for the DSM-5 (CAPS-5).
- The PTSD diagnosis in the DSM-5 expands on previous criteria and includes witnessing a traumatic event or learning that a family member or friend experienced a traumatic event in addition to experiencing it directly, and includes repeated exposures such as with first responders, law enforcement, and individuals exposed to repeated trauma based on minoritized identities.
- Multidisciplinary treatment approaches, using a CBT framework, have been found to be effective for comorbid chronic pain and PTSD.