The Shared Neuroanatomy and Neurobiology of Comorbid Chronic Pain and PTSD: Therapeutic Implications

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

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.

Neuroactive steroids and the pathophysiology of PTSD: Biomarkers for treatment targeting

Posttraumatic stress disorder (PTSD) is a disabling psychiatric disorder that arises after acute or chronic exposure to threatened death, serious injury, or sexual violence. The pathophysiology of PTSD is complex and involves dysregulation of multiple interacting brain regions and neurobiological systems including the sympathetic nervous system, the hypothalamic-pituitary-adrenal (HPA) axis, and the immune system. Deficient biosynthesis of neurosteroids that positively modulate GABAA receptor function, including allopregnanolone (Allo) and its equipotent stereoisomer pregnanolone (PA), also affects a subpopulation of individuals with PTSD and is associated with increased PTSD risk, severity, chronicity and treatment resistance. The synthesis of these neuroactive steroids by the brain, adrenal glands, and gonads may be influenced by stress, drugs, social isolation and other factors with impact on the balance of inhibitory versus excitatory (I/E) neurotransmission in brain. These neuroactive steroids are thus considered a potential target for new PTSD therapeutics. In this review, we first present studies in humans and rodents performed over the past 20 years that have shaped our current understanding of the role of Allo and PA in the pathophysiology of PTSD. We will also discuss the means by which rigorous measurement of neurosteroids can be used to identify individually-variable dysfunctional patterns of neurosteroidogenesis that could be targeted to prevent or treat PTSD. This broadened precision medicine approach to diagnosis of neuroendocrinopathies associated with PTSD may aid in reducing PTSD risk and facilitating the effective prescribing of PTSD therapeutics. We hope that such an approach will also forestall development of individually variable but common psychiatric, substance abuse, and medical PTSD-comorbidities.

Chronic pain and comorbid posttraumatic stress disorder: Potential mechanisms, conceptualizations, and interventions

Posttraumatic stress disorder (PTSD) is a common comorbidity to chronic pain, among others due to potentially shared posttraumatic origin. There has been growing interest in this field in the past decades, also providing some important studies to support our understanding of this comorbidity and how to address it in clinical practice. However, there are still important questions, particularly regarding the potentially shared vulnerabilities, mutually maintaining mechanisms, and how to best treat this comorbidity. This article provides a brief and up-to-date review of what we argue to be some of the most important studies within the field of chronic pain and comorbid PTSD and will discuss some of the current challenges and ways forward.

Analysis of the current status and factors influencing post-traumatic stress disorder in elderly patients with knee osteoarthritis: a cross-sectional study

Existing studies have focused on post-traumatic stress disorder (PTSD) after surgery in patients with knee osteoarthritis (KOA), whereas PTSD in non-operated elderly KOA patients has not been adequately studied. The aim was to assess the current status of PTSD and its influencing factors among non-surgical elderly KOA patients. From October to November 2021, a cross-sectional study was conducted among 320 consecutive patients aged ≥ 65 years with radiologically confirmed KOA and no history of knee surgery or psychiatric disorders, recruited from three community hospitals in Changsha, Hunan Province. A total of 314 participants completed validated assessments for PTSD (PTSD Checklist-Civilian Version), pain (Numerical Rating Scale), anxiety (Generalized Anxiety Disorder Scale), depression (Patient Health Questionnaire-9), and social support (Social Support Rating Scale). Data were analyzed using non-parametric tests and Spearman correlation. Structural equation modeling (SEM) was performed with Amos 24.0, employing maximum likelihood estimation and 1000 bootstrap samples to test mediation effects. Among 314 analyzed participants (mean age 72.91 ± 6.384 years; 60.80% female and 39.20% males), PTSD prevalence was 18.20%. Significantly higher PTSD risk was associated with low education levels (Z=-2.398, P = 0.016), low salaries (H = -2.398, P = 0.005), unemployed patients (H = 10.030, P = 0.007), no exercise (H = 9.328, P = 0.025), smoking (Z = -2.504, P = 0.012) and no leisure activities (Z=-2.074, P = 0.038). Structural equation modeling revealed a direct effect of depression on PTSD with the path coefficient of 0.701 (95% CI 0.518-0.879, P = 0.001) and an indirect effect of pain on PTSD through social support with the path coefficient of -0.014 (95% CI -0.049 to -0.001, P = 0.035 < 0.05). Non-surgical elderly patients with knee osteoarthritis exhibit clinically significant post-traumatic stress disorder rates (18.20%), primarily driven by depression and mediated through pain-social support pathways. These findings underscore the need for integrated biopsychosocial interventions targeting pain management, mental health screening, and social support enhancement in this population.

Bidirectional Mendelian randomization study reveals interplay between multisite chronic pain and Post-traumatic stress disorder

To determine the causal relationship between multisite chronic pain (MCP) and post-traumatic stress disorder (PTSD) using Mendelian Randomization (MR) analysis. Genome-wide summary statistics for MCP and PTSD were obtained. Linkage disequilibrium score regression (LDSC) analysis was used to assess genetic correlation. Independent SNPs associated with MCP and PTSD were used as instrumental variables for forward and reverse MR analyses. The inverse variance weighted (IVW) method was the primary analysis, with additional sensitivity tests to ensure robustness. LDSC identified a significant genetic correlation between MCP and PTSD (rg = 0.635, P = 1.40E-110). The forward MR analysis indicated a positive causal association between the number of MCP sites and the PTSD risk (Odds Ratio [OR] = 1.103, 95% CI: 1.026-1.186, P = 7.89E-03). Conversely, the reverse MR analysis showed that PTSD significantly increased the number of MCP sites (β = 0.244, 95% CI: 0.143-0.345, P = 2.08E-06). Sensitivity tests suggested the robustness of the MR estimation, indicating no significant heterogeneity or horizontal pleiotropy. A bidirectional positive causal relationship between MCP and PTSD was identified, highlighting the need for integrated treatment and preventive strategies that address both conditions simultaneously to improve health outcomes.

Multisite pain among United States Veterans with posttraumatic stress disorder: Prevalence, predictors, and associations with symptom clusters

Persistent pain in multiple distinct body sites is associated with poorer functional outcomes above and beyond pain intensity and interference. Veterans, and especially those with posttraumatic stress disorder (PTSD), may be at risk for multisite pain. However, the research to date characterizing this presentation is limited. This secondary analysis examined the prevalence of multisite pain in a cross-sectional sample of Veterans and explored demographic, military service-related, and PTSD symptom cluster variables associated with multisite pain among those with clinically significant PTSD symptoms. Participants were 4303 post-9/11 U.S. Veterans (16.55% female gender, 58.45% White/Caucasian, Mage = 35.52), of whom 1375 (31.95%) had clinically significant PTSD symptoms. Multisite pain was defined as endorsing pain that "bothered [me] a lot" in ≥3 body sites out of 5 on the Patient Healthcare Questionnaire-15. A total of 20.03% of all participants, and 40.00% of those with likely PTSD, reported multisite pain. Female gender (OR = 1.55), older age (OR = 1.70), minority race identification (White/Caucasian racial identity OR = 0.75), history of military sexual trauma (OR = 1.99), and spine, abdomen and joint/muscle injuries (ORs = 1.66-3.68) were associated with higher odds of multisite pain. Adjusting for these potential confounders, higher z-scores on the PTSD arousal/reactivity (OR = 1.58, p <.001) subscale was associated with higher multisite pain odds. In summary, multisite pain was common among Veterans with PTSD, especially those who experienced military sexual trauma or certain physical injuries. Multisite pain and PTSD may be associated due to a shared threat reactivity mechanism. PERSPECTIVE: This study investigates the rates and factors associated with having pain in three or more distinct body sites (multisite pain) among United States Veterans. The study findings highlight the unique importance of specific posttraumatic stress symptoms and experiences associated with multisite pain.

Examining the epigenetic transmission of risk for chronic pain associated with paternal post-traumatic stress disorder: a focus on veteran populations

Chronic pain is a public health problem that significantly reduces quality of life. Although the aetiology is often unknown, recent evidence suggests that susceptibility can be transmitted intergenerationally, from parent to child. Post-traumatic stress disorder (PTSD) is a debilitating psychological disorder, often associated with chronic pain, that has high prevalence rates in military personnel and Veterans. Therefore, we aimed to characterise the epigenetic mechanisms by which paternal trauma, such as PTSD, is transmitted across generations to confer risk in the next generation, specifically focusing on Veterans where possible. Numerous overlapping neurological pathways are implicated in both PTSD and chronic pain; many of which are susceptible to epigenetic modification, such as DNA methylation, histone modifications, and RNA regulation. Hence, epigenetic changes related to pain perception, inflammation, and neurotransmission may influence an individual's predisposition to chronic pain conditions. We also examine the effects of PTSD on parenting behaviours and discuss how these variations could impact the development of chronic pain in children. We highlight the need for further research regarding the interactions between paternal trauma and epigenetic processes to ultimately generate effective prevention and therapeutic strategies for Veterans who have been affected by PTSD and chronic pain.

Neuropeptide Y and Pain: Insights from Brain Research

Neuropeptide Y (NPY) is a highly conserved neuropeptide with widespread distribution in the central nervous system and diverse physiological functions. While extensively studied for its inhibitory effects on pain at the spinal cord level, its role in pain modulation within the brain remains less clear. This review aims to summarize the complex landscape of supraspinal NPY signaling in pain processing. We discuss the expression and function of NPY receptors in key pain-related brain regions, including the parabrachial nucleus, periaqueductal gray, amygdala, and nucleus accumbens. Additionally, we highlight the potent efficacy of NPY in attenuating pain sensitivity and nociceptive processing throughout the central nervous system. NPY-based therapeutic interventions targeting the central nervous system represent a promising avenue for novel analgesic strategies and pain-associated comorbidities.

Using lifestyle interventions and the gut microbiota to improve PTSD symptoms

Posttraumatic stress disorder is part of a spectrum of psychological symptoms that are frequently linked with a single defining traumatic experience. Symptoms can vary over the lifespan in intensity based on additional life stressors, individual stability, and connectedness to purpose. Historically, treatment has centered on psychotropic agents and individual and group therapy to increase the individual's window of tolerance, improve emotional dysregulation, and strengthen relationships. Unfortunately, there is a growing segment of individuals with posttraumatic stress disorder who do not respond to these traditional treatments, perhaps because they do not address the multidirectional relationships between chronic cortisol, changes in the brain gut microbiota system, neuroinflammation, and posttraumatic symptoms. We will review the literature and explain how trauma impacts the neuroendocrine and neuroimmunology within the brain, how these processes influence the brain gut microbiota system, and provide a mechanism for the development of posttraumatic stress disorder symptoms. Finally, we will show how the lifestyle psychiatry model provides symptom amelioration.

Inflammatory injury induces pain sensitization that is expressed beyond the site of injury in male (and not in female) mice

Pain is a crucial protective mechanism for the body. It alerts us to potential tissue damage or injury and promotes the avoidance of harmful stimuli. Injury-induced inflammation and tissue damage lead to pain sensitization, which amplifies responses to subsequent noxious stimuli even after an initial primary injury has recovered. This phenomenon, commonly referred to as hyperalgesic priming, was investigated in male and female mice to determine whether it is specific to the site of previous injury. We used 10μl of 50 % Freund's complete adjuvant (CFA) administered to the left hind paw as a model of peripheral injury. Both male and female mice exhibited robust site-specific mechanical hypersensitivity after CFA, which resolved within one-week post-injection. After injury resolution, only male CFA-primed mice showed enhanced and prolonged mechanical sensitivity in response to a chemical challenge or a single 0.5 mA electric footshock. Among CFA-primed male mice, shock-induced mechanical hypersensitivity was expressed in both the left (previously injured) and the right (uninjured) hind paws, suggesting a pivotal role for altered centralized processes in the expression of pain sensitization. These findings indicate that pain history regulates sensory responses to subsequent mechanical and chemical pain stimuli in a sex-specific manner-foot-shock-induced hyperalgesic priming expression among male mice generalized beyond the initial injury site.

A Computational Framework for Understanding the Impact of Prior Experiences on Pain Perception and Neuropathic Pain

Pain perception is influenced not only by sensory input from afferent neurons but also by cognitive factors such as prior expectations. It has been suggested that overly precise priors may be a key contributing factor to chronic pain states such as neuropathic pain. However, it remains an open question how overly precise priors in favor of pain might arise. Here, we first verify that a Bayesian approach can describe how statistical integration of prior expectations and sensory input results in pain phenomena such as placebo hypoalgesia, nocebo hyperalgesia, chronic pain, and spontaneous neuropathic pain. Our results indicate that the value of the prior, which is determined by the internal model parameters, may be a key contributor to these phenomena. Next, we apply a hierarchical Bayesian approach to update the parameters of the internal model based on the difference between the predicted and the perceived pain, to reflect that people integrate prior experiences in their future expectations. In contrast with simpler approaches, this hierarchical model structure is able to show for placebo hypoalgesia and nocebo hyperalgesia how these phenomena can arise from prior experiences in the form of a classical conditioning procedure. We also demonstrate the phenomenon of offset analgesia, in which a disproportionally large pain decrease is obtained following a minor reduction in noxious stimulus intensity. Finally, we turn to simulations of neuropathic pain, where our hierarchical model corroborates that persistent non-neuropathic pain is a risk factor for developing neuropathic pain following denervation, and additionally offers an interesting prediction that complete absence of informative painful experiences could be a similar risk factor. Taken together, these results provide insight to how prior experiences may contribute to pain perception, in both experimental and neuropathic pain, which in turn might be informative for improving strategies of pain prevention and relief.

Childhood trauma, PTSD/CPTSD and chronic pain: A systematic review

BACKGROUND

Despite the growing body of literature on posttraumatic stress disorder (PTSD) and chronic pain comorbidity, studies taking into account the role of childhood exposure to traumatic and adverse events remains minimal. Additionally, it has been well established that survivors of childhood trauma may develop more complex reactions that extend beyond those observed in PTSD, typically categorized as complex trauma or CPTSD. Given the recent introduction of CPTSD within diagnostic nomenclature, the aim of the present study is to describe associations between childhood trauma in relation to PTSD/CPTSD and pain outcomes in adults with chronic pain.

METHODS

Following PRSIMA guidelines, a systematic review was performed using the databases Pubmed, PsychInfo, Psychology and Behavioral Sciences Collection, and Web of Science. Articles in English or French that reported on childhood trauma, PTSD/CPTSD and pain outcomes in individuals with chronic pain were included. Titles and abstracts were screened by two authors independently and full texts were consequently evaluated and assessed on methodological quality using JBI checklist tools. Study design and sample characteristics, childhood trauma, PTSD/CPTSD, pain outcomes as well as author's recommendations for scientific research and clinical practice were extracted for analyses.

RESULTS

Of the initial 295 search records, 13 studies were included in this review. Only four studies explicitly assessed links between trauma factors and pain symptoms in individuals with chronic pain. Findings highlight the long-term and complex impact of cumulative childhood maltreatment (e.g., abuse and neglect) on both PTSD/CPTSD and chronic pain outcomes in adulthood.

CONCLUSION

This review contributes to current conceptual models of PTSD and chronic pain comorbidity, while adding to the role of childhood trauma and CPTSD. The need for clinical and translational pain research is emphasized to further support specialized PTSD/CPTSD treatment as well as trauma-informed pain management in routine care.

Pain neuroscience education improves post-traumatic stress disorder, disability, and pain self-efficacy in veterans and service members with chronic low back pain: Preliminary results from a randomized controlled trial with 12-month follow-up

Post-traumatic stress disorder (PTSD) and chronic low back pain (CLBP) are frequently co-morbid. Some research suggests that PTSD and CLBP may share common neurobiological mechanisms related to stress. Traditional biomedical education may be ineffective for PTSD and CLBP, especially when co-morbid. The purpose of this study is to determine if pain neuroscience education (PNE) is more effective than traditional education in reducing PTSD, disability, pain, and maladaptive beliefs in patients with CLBP. Participants with CLBP and possible PTSD/PTSD-symptoms were recruited for this study. Participants were randomly allocated to a PNE group or a traditional education group. The intervention included 30 minutes of education followed by a standardized exercise program once a week for 4-weeks with a 4 and 8-week follow-up and healthcare utilization assessed at 12-months. Forty-eight participants consented for this research study with 39 allocated to treatment (PNE n = 18, traditional n = 21). PNE participants were more likely to achieve a clinically meaningful reduction in PTSD symptoms and disability at short-term follow-up. At 12-months, the PNE group utilized healthcare with 76% lower costs. In participants with CLBP, PNE may reduce hypervigilance toward pain and improve PTSD symptoms. Participants who received PNE were more confident body-tissues were safe to exercise. These beliefs about pain could contribute to a decrease in perceived disability and healthcare consumption for CLBP.

Posttraumatic Stress and Opioid Use and Pain among Individuals with Probable Posttraumatic Stress Disorder and Self-Reported Chronic Pain: The Role of Health Literacy

BACKGROUND

Chronic pain and opioid misuse are a prevalent comorbidity with deleterious health outcomes. Growing work indicates that posttraumatic stress disorder (PTSD) can increase the risk for chronic pain and opioid misuse and dependence. However, there is little understanding of social determinants of health (SDoH) that may account for interrelations of PTSD with chronic pain and opioid misuse and dependence. Health literacy is one relevant SDoH construct, reflecting the ability to gather, process, and comprehend health-related information required to engage in a healthcare setting.

OBJECTIVE

The purpose of the present cross-sectional study was to examine the indirect effect of health literacy in the association between PTSD and opioid misuse, opioid dependence, pain intensity, and pain disability.

METHOD

The sample included 142 adults (Mage = 35.2, SD = 9.9; 67.4% female; 70.1% White/Caucasian) with self-reported chronic pain and probable PTSD who were using opioid medication.

RESULTS

Results demonstrated that PTSD symptom severity had a small indirect effect on opioid misuse and opioid dependence via health literacy; no indirect effects were evident for pain intensity and disability.

CONCLUSION

The present investigation provides evidence that health literacy may serve as an important explanatory factor in associations between PTSD symptom severity and opioid misuse and dependence among adults with co-occurring probable PTSD and chronic pain.

Veterans with chronic pain: Examining gender differences in pain type, overlap, and the impact of post-traumatic stress disorder

BACKGROUND

Women are more likely to experience multiple overlapping pain conditions (MOPCs) relative to men. Post-traumatic stress disorder can negatively impact the severity and trajectory of chronic pain and its treatment. Specific associations between gender, post-traumatic stress disorder (PTSD), and MOPCs require further examination.

METHODS

A cohort of all Veterans in 2021 who met criteria for one or more of 12 chronic pain types was created using national Veterans Health Administration administrative data. MOPCs were defined as the number of pain types for which each patient met criteria. Multivariable logistic regression models estimated gender differences in frequency for each of the 12 pain subtypes, after controlling for demographics and comorbidities. Negative binomial regression was used to estimate gender differences in the count of MOPCs and to explore moderation effects between gender and PTSD.

RESULTS

The cohort included 1,936,859 Veterans with chronic pain in 2021, which included 12.5% women. Among those with chronic pain, women Veterans had higher rates of MOPCs (mean = 2.3) relative to men (mean = 1.9): aIRR = 1.31, 95% CI: 1.30-1.32. PTSD also served as an independent risk factor for MOPCs in adjusted analysis (aIRR = 1.23, 95% CI: 1.23-1.24). The interaction term between gender and PTSD was not significant (p = 0.87). Independent of PTSD, depressive disorders also served as a strong risk factor for MOPCs (aIRR = 1.37, 95% CI: 1.36-1.37).

CONCLUSIONS

Individuals with MOPCs and PTSD may have complex treatment needs. They may benefit from highly coordinated trauma-sensitive care and integrated interventions that simultaneously address pain and PTSD.

SIGNIFICANCE

Women were significantly more likely than men to experience MOPCs. PTSD was also significantly, independently, associated with MOPCs. Patients, particularly women, may benefit from tailored interventions that address both trauma and MOPCs.

Immediate Effects of Integrative Health and Medicine Modalities Among Outpatients With Moderate-To-Severe Symptoms

Background

Patients seeking integrative health and medicine (IHM) modalities often present with multiple physical and psychological concerns. Research supports IHM's effectiveness for addressing symptoms over longer time periods. However, few studies have evaluated immediate outpatient effects.

Objective

This study describes pre-encounter patient-reported outcome (PRO) clusters and examines the immediate clinical effectiveness of IHM modalities on pain, stress, and anxiety among outpatients with moderate-to-severe symptoms.

Methods

A retrospective review was conducted of encounters among adults presenting to outpatient acupuncture, chiropractic, massage, integrative medicine consultation, or osteopathic manipulation treatment between January 2019 and July 2020. Encounters were included if patients reported pre-encounter pain, stress, or anxiety ≥4 on a numeric rating scale (NRS). Outcome analyses included random effects for patient and provider using a mixed model.

Results

Across 7335 clinical encounters among 2530 unique patients (mean age: 49.14 years; 81.0% female; 75.9% White; 15.8% Black/African American), the most common pre-encounter PRO clusters were pain, stress, and anxiety ≥4 (32.4%); pain ≥4 only (31.3%); and stress and anxiety ≥4 (15.6%). Clinically meaningful single-encounter mean [95% CI] changes were observed across all modalities in pain (-2.50 [-2.83, -2.17]), stress (-3.22 [-3.62, -2.82]), and anxiety (-3.05 [-3.37, -2.73]).

Conclusion

Patients presenting to outpatient IHM with moderate-to-severe symptoms most often presented with pain, stress, and anxiety ≥4 on the NRS. Multiple IHM modalities yielded clinically meaningful (≥2 unit) immediate reductions in these symptoms. Future research measuring immediate and longitudinal effectiveness is needed to optimize the triage and coordination of IHM modalities to meet patients' needs.

The Roles of Endogenous Opioids in Placebo and Nocebo Effects: From Pain to Performance to Prozac

Placebo and nocebo effects have been well documented for nearly two centuries. However, research has only relatively recently begun to explicate the neurobiological underpinnings of these phenomena. Similarly, research on the broader social implications of placebo/nocebo effects, especially within healthcare delivery settings, is in a nascent stage. Biological and psychosocial outcomes of placebo/nocebo effects are of equal relevance. A common pathway for such outcomes is the endogenous opioid system. This chapter describes the history of placebo/nocebo in medicine; delineates the current state of the literature related to placebo/nocebo in relation to pain modulation; summarizes research findings related to human performance in sports and exercise; discusses the implications of placebo/nocebo effects among diverse patient populations; and describes placebo/nocebo influences in research related to psychopharmacology, including the relevance of endogenous opioids to new lines of research on antidepressant pharmacotherapies.

Mental Health Predictors of Response to Standard Medical Intervention at a Military Pain Specialty Clinic

INTRODUCTION

Chronic pain among active duty service members can negatively impact operational readiness and contributes to significant health care costs within military treatment facilities. Response to standard medical intervention (SMI) for chronic pain is highly variable. The objective of the current study was to examine whether mental health indicators predict individual variation in response to SMI for chronic pain in a military pain specialty clinic.

METHODS

This is a retrospective observational study of data previously collected at the Pain Medicine Center at Naval Medical Center San Diego (NMCSD) approved by the NMCSD Institutional Review Board. We included 286 ADSMs who completed the Pain Assessment Screening Tool and Outcomes Registry (PASTOR) at two assessment points (mean = 118.45 days apart, SD = 37.22) as part of standard care. Hierarchical linear regression analyses were conducted to examine whether pretreatment mental health measures predict changes in the pain impact score (PIS)-a composite measure of pain intensity, pain interference, and physical functioning-over the course of treatment.

RESULTS

After controlling for pretreatment PIS, pretreatment PTSD symptoms, fatigue, and anger were all significant predictors of posttreatment PIS: Higher PTSD symptoms, higher fatigue, and lower anger predicted poorer response to treatment (all Ps < .05).

CONCLUSION

Higher pretreatment PTSD and fatigue symptoms may portend poorer response to SMI for chronic pain. Poor response to treatment may also be predicted by lower pretreatment anger. Further investigation is warranted to identify the best strategies for treating chronic pain in military treatment facilities when these conditions are identified during initial evaluation.

Acute changes in affective valence and perceived distress predict reductions in PTSD symptom severity

There is a growing amount of experimental evidence demonstrating therapeutic chronic effects of exercise (e.g., resistance exercise, running, and walking) on PTSD symptoms. However, it is currently unclear how individuals with PTSD experience exercise within individual exercise sessions (e.g., pleasurable or distressing), and if these acute experiences influence PTSD symptoms over time.

PURPOSE

The objective of this study was to examine the acute effects of high intensity resistance exercise on affect, perceived arousal, and distress among individuals who screened positive for PTSD, using a randomized controlled design. Additionally, this study sought to explore longitudinal relations among affect, arousal, distress, and PTSD symptom severity.

METHODS

This study analyzed pooled data from two methodologically similar randomized controlled trials (i.e., a pilot and replication study). Participants (n = 52) were randomly assigned to exercise or non-exercise time-matched control. Data were analyzed with a series of longitudinal mixed-effects regression models.

RESULTS

The analyses suggest that positive affect increased, and distress decreased significantly during exercise sessions, relative to control. Independent of group, increases in positive affect and decreases in distress also significantly predicted decreases in PTSD symptom severity over the course of the study.

CONCLUSIONS

Taken together, these findings suggest that high intensity resistance exercise is safe for individuals who screen positive for PTSD, pleasurable, and may have a therapeutic impact on trauma survivors. No evidence for symptom exacerbation was found. Future experimental studies are needed to verify these findings and determine if the observed relationships are similar for other exercise modes, durations, and intensities.

Traumatic Events, Posttraumatic Stress Disorder, and Central Sensitization in Chronic Pain Patients of a German University Outpatient Pain Clinic

OBJECTIVE

Posttraumatic stress disorder (PTSD) and traumatic life events are often coupled to chronic pain, possibly linked by central sensitization. We wanted to assess the prevalence of traumatic events and PTSD in chronic pain patients of a German university hospital outpatient pain clinic. Moreover, we evaluated the extent of indicators and co-occurring traits of central sensitization in comorbid patients.

METHODS

We retrospectively divided 914 chronic pain patients into four groups depending on their trauma severity: no trauma, accidental trauma, interpersonal trauma, and PTSD. We collected electronic pain drawings focusing on pain area and widespreadness, as well as information about pain intensity, sleep impairment, disability, stress, anxiety, depression, and somatization. Differences between groups were calculated using Kruskal-Wallis with post-hoc Mann-Whitney tests.

RESULTS

Of 914 patients, 231 (25%) had no trauma, 210 (23%) had accidental traumas, 283 (31%) had interpersonal traumas, 99 (11%) had PTSD, and 91 (10%) could not be classified. We observed statistically significant differences between groups in pain area and widespreadness, as well as maximal pain, sleep impairment, disability, stress, anxiety, depression, and somatization. The severity of symptoms increased with trauma severity.

CONCLUSIONS

Traumatic life events and PTSD are frequent in chronic pain patients. The increased pain area and widespreadness, as well as the increased negative impact on co-occurring traits of sensory sensitivity (anxiety, depression, somatization), are compatible with central sensitization in comorbid patients. Therefore, a heightened awareness of the comorbidity between traumatic experiences and chronic pain is recommended.

Baicalein exerts anxiolytic and antinociceptive effects in a mouse model of posttraumatic stress disorder: Involvement of the serotonergic system and spinal delta-opioid receptors

Post-traumatic stress disorder (PTSD) is a serious mental disease featured by a stress dysfunction that occurs after an individual has faced intense mental stress, often accompanied by anxiety and chronic pain. Currently, the mainstream drug for PTSD is serotonin reuptake inhibitors (SSRIs), however, their pain management for patients is limited. Baicalein, a Chinese traditional herbal medicine, has shown promising results in treating anxiety, depression, and pain. In this study, we found that baicalein may alleviate single prolonged stress (SPS)-induced PTSD-like behaviors in mice without altering baseline nociceptive sensitivity or activity. Meanwhile, baicalein increased the noradrenaline (NE) and serotonin (5-HT) content and decreased the ratio of 5-hydroxyindoleacetic acid (5-HIAA)/5-HT by inhibiting the activity of monoamine oxidase A (MAO-A) in SPS-induce mice. The anxiolytic and antinociceptive effects induced by baicalein were totally abolished by 5-HT depleting agents. Moreover, the anxiolytic effects of baicalein could be abolished by the 5-HT_1A receptor antagonist WAY-100635, and the analgesic effects could be abolished by delta-opioid receptor antagonists in the spinal. Taken together, our study provides compelling evidence that baicalein reversed anxiety-like behaviors and neuropathic pain in PTSD through serotonergic system and spinal delta-opioid receptors.

Headache comorbidity in refugees and migrants with post-traumatic stress disorder

BACKGROUND

Headache is often comorbid with post-traumatic stress disorder yet overlooked in health assessments of refugees.

OBJECTIVES

To describe prevalence of severe headache among refugees with post-traumatic stress disorder and compare severity of post-traumatic stress disorder symptoms and treatment outcomes among those with and without severe headache.

METHODS

This follow-up study used data from the Danish Database on Refugees with Trauma. Participants were recruited from 2009 to 2015 at a specialized psychiatric clinic. Prevalence of severe headache was computed by age, sex, and history of head injury or torture. Severe headache was defined as maximum headache scores on the Hopkins Symptom Checklist, Symptom Checklist-90 or the Visual Analogue Scale. Groups with and without severe headache were described according to validated questionnaires before and after 12-18 months of multidisciplinary treatment for post-traumatic stress disorder. Regression analyses were used to analyze associations between headache at start of treatment and symptom burden post-treatment, controlled for pre-treatment scores and possible confounders.

RESULTS

Among 403 female and 489 male participants, nearly all (97.5%) complained of headaches. Severe headache prevalence was 31.4% to 50.0% (depending on which questionnaire was used) and was significantly more common among females and those aged 30-49 years. There was no clear relationship between headache and head injury or torture. Participants with severe headache had heavier symptom burdens compared to those without severe headache. Post-treatment, headache prevalence by age and sex did not change significantly. Those without severe headache showed a tendency toward improvement in outcome measures; this was not seen among those with severe headache. Pre-treatment headache scores were correlated with all outcome measures. Regression analyses controlled for pre-treatment scores of the outcome variables showed associations between pre-treatment headache scores (Hopkins Symptom Checklist or Symptom Checklist-90) and post-treatment scores for intrusion, numbing, hyperarousal, anxiety, disability, and quality of life (all p < 0.02).

CONCLUSION

Headache is a prevalent comorbid condition among refugees with post-traumatic stress disorder. Measures of pre-treatment headache severity appear to predict post-traumatic stress disorder treatment outcomes. Severe headache adversely affects post-traumatic stress disorder prognosis. Assessment and treatment options should be studied further.

Chronic Pain and Psychiatric Conditions

Introduction

Chronic pain is a common condition with high socioeconomic and public health burden. A wide range of psychiatric conditions are often comorbid with chronic pain and chronic pain conditions, negatively impacting successful treatment of either condition. The psychiatric condition receiving most attention in the past with regard to chronic pain comorbidity has been major depressive disorder, despite the fact that many other psychiatric conditions also demonstrate epidemiological and genetic overlap with chronic pain. Further understanding potential mechanisms involved in psychiatric and chronic pain comorbidity could lead to new treatment strategies both for each type of disorder in isolation and in scenarios of comorbidity.

Methods

This article provides an overview of relationships between DSM-5 psychiatric diagnoses and chronic pain, with particular focus on PTSD, ADHD, and BPD, disorders which are less commonly studied in conjunction with chronic pain. We also discuss potential mechanisms that may drive comorbidity, and present new findings on the genetic overlap of chronic pain and ADHD, and chronic pain and BPD using linkage disequilibrium score regression analyses.

Results

Almost all psychiatric conditions listed in the DSM-5 are associated with increased rates of chronic pain. ADHD and BPD are significantly genetically correlated with chronic pain. Psychiatric conditions aside from major depression are often under-researched with respect to their relationship with chronic pain.

Conclusion

Further understanding relationships between psychiatric conditions other than major depression (such as ADHD, BPD, and PTSD as exemplified here) and chronic pain can positively impact understanding of these disorders, and treatment of both psychiatric conditions and chronic pain.

Parental post-traumatic stress disorder and increased risk of chronic pain conditions and major psychiatric disorders in their offspring

BACKGROUND

Previous research suggests that individuals with post-traumatic stress disorder (PTSD) have higher risk of chronic pain symptoms. It remains unknown whether risk of chronic pain symptoms occurs in the offspring of parents with PTSD. This study aimed to explore the risk of chronic pain conditions and depression in the offspring of parents with PTSD.

METHODS

Between 1996 and 2011, we included subjects whose parents had PTSD and controls with parents without PTSD or any major psychiatric disorders (MPDs) from the Taiwan National Health Research Database. The controls (1:10) were matched for age, sex, time of birth, income, and residence. Poisson regression was applied to estimate the risk of chronic pain conditions and MPDs between case and control cohorts during the study period. The chronic pain conditions assessed were migraine, tension headache, fibromyalgia, peripheral neuropathy, dorsopathies, dysmenorrhea, irritable bowel syndrome (IBS), and dyspepsia.

RESULTS

We included 1139 cases and 11,390 matched controls. After adjusting for demographics and family history of psychiatric comorbidities, offspring of parents with PTSD had higher risk for depressive disorder [reported as odds ratio (OR) with 95% confidence interval (CI): 2.59, 1.71-3.92] than controls. For chronic pain conditions, offspring of parents with PTSD had higher risk for migraine (2.01, 1.01-3.98) and IBS (1.55, 1.02-2.34) than controls.

CONCLUSIONS

Healthcare workers should be aware that offspring of parents with PTSD have a higher risk of chronic pain conditions and depressive disorder. Further intervention to mitigate the risk is warranted.

Emotional numbing in PTSD is associated with lower amygdala reactivity to pain

Posttraumatic stress disorder (PTSD) is associated with altered pain perception, namely increased pain threshold and higher pain response. While pain consists of physiological and affective components, affective components are often overlooked. Similar patterns of increased threshold-high response in PTSD were shown in response to emotional stimuli, i.e., emotional numbing. As both emotional numbing and pain processing are modulated by the amygdala, we aimed to examine whether individuals diagnosed with PTSD show lower amygdala activation to pain compared with combat controls, and whether the amygdala responses to pain correlates with emotional numbing. To do so, two independent samples of veterans (original study: 44 total (20 PTSD); conceptual replication study: 40 total (20 PTSD)) underwent threat conditioning, where a conditioned stimulus (CS+; visual stimulus) was paired with an unconditioned stimulus (US; electric-shock). We contrasted the amygdala activity to the CS + US pairing with the CS+ presented alone and correlated it with emotional numbing severity. In both samples, the PTSD group showed a robust reduction in amygdala reactivity to shock compared to the Combat Controls group. Furthermore, amygdala activation was negatively correlated with emotional numbing severity. These patterns were unique to the amygdala, and did not appear in comparison to a control region, the insula, a pivotal region for the processing of pain. To conclude, amygdala response to pain is lower in individuals with PTSD, and is associated with emotional numbing symptoms. Lower amygdala reactivity to mild pain may contribute to the "all-or-none" reaction to stressful situations often observed in PTSD.

The role of pain and socioenvironmental factors on posttraumatic stress disorder symptoms in traumatically injured adults: A 1-year prospective study

Approximately 20% of individuals who experience a traumatic injury will subsequently develop posttraumatic stress disorder (PTSD). Physical pain following traumatic injury has received increasing attention as both a distinct, functionally debilitating disorder and a comorbid symptom related to PTSD. Studies have demonstrated that both clinician-assessed injury severity and patient pain ratings can be important predictors of nonremitting PTSD; however, few have examined pain and PTSD alongside socioenvironmental factors. We postulated that both area- and individual-level socioeconomic circumstances and lifetime trauma history would be uniquely associated with PTSD symptoms and interact with the pain-PTSD association. To test these effects, pain and PTSD symptoms were assessed at four visits across a 1-year period in a sample of 219 traumatically injured participants recruited from a Level 1 trauma center. We used a hierarchal linear modeling approach to evaluate whether (a) patient-reported pain ratings were a better predictor of PTSD than clinician-assessed injury severity scores and (b) socioenvironmental factors, specifically neighborhood socioeconomic disadvantage, individual income, and lifetime trauma history, influenced the pain-PTSD association. Results demonstrated associations between patient-reported pain ratings, but not clinician-assessed injury severity scores, and PTSD symptoms, R2( fvm ) = .65. There was a significant interaction between neighborhood socioeconomic disadvantage and pain such that higher disadvantage decreased the strength of the pain-PTSD association but only among White participants, R2( fvm ) = .69. Future directions include testing this question in a larger, more diverse sample of trauma survivors (e.g., geographically diverse) and examining factors that may alleviate both pain and PTSD symptoms.

Heightened autonomic reactivity to negative affective stimuli among active duty soldiers with PTSD and opioid-treated chronic pain

Within military populations, chronic pain conditions and posttraumatic stress disorder (PTSD) frequently co-occur, however, little research has examined the psychophysiological correlates of this comorbidity among active-duty soldiers. The current study examined physiological reactivity to negative affective stimuli among 30 active duty soldiers with chronic pain conditions treated with long-term opioid therapy. Participants completed a diagnostic interview and self-report measures. Then, their heart rate and skin temperature were recorded during an affective picture-viewing task. Soldiers with PTSD exhibited greater increases in the ratio of low-to-high frequency heart rate variability (LF/HF HRV) while viewing negative affective images than soldiers without PTSD. PTSD symptom severity was positively associated with LF/HF HRV reactivity and negatively associated with skin temperature reactivity. Additionally, opioid craving was associated with LF/HF HRV and skin temperature reactivity among soldiers with PTSD. Taken together, the results of the present study provide evidence for heightened sympathetic nervous system reactivity among soldiers with comorbid chronic pain and PTSD, underscoring the importance of intervening on potential risk factors for these conditions.

The neurobiology of childhood trauma, from early physical pain onwards: as relevant as ever in today's fractured world

Background: The situation in the world today, encompassing multiple armed conflicts, notably in Ukraine, the Coronavirus pandemic and the effects of climate change, increases the likelihood of childhood exposure to physical injury and pain. Other effects of these worldwide hardships include poverty, malnutrition and starvation, also bringing with them other forms of trauma, including emotional harm, neglect and deliberate maltreatment. Objective: To review the neurobiology of the systems in the developing brain that are most affected by physical and emotional trauma and neglect. Method: The review begins with those that mature first, such as the somatosensory system, progressing to structures that have a more protracted development, including those involved in cognition and emotional regulation. Explored next are developing stress response systems, especially the hypothalamic-pituitary-adrenal axis and its central regulator, corticotropin-releasing hormone. Also examined are reward and anti-reward systems and genetic versus environmental influences. The behavioural consequences of interpersonal childhood trauma, focusing on self-harm and suicide, are also surveyed briefly. Finally, pointers to effective treatment are proffered. Results: The low-threshold nature of circuitry in the developing brain and lack of inhibitory connections therein result in heightened excitability, making the consequences of both physical and emotional trauma more intense. Sensitive and critical periods in the development of structures such as the amygdala render the nervous system more vulnerable to insults occurring at those points, increasing the likelihood of psychiatric disorders, culminating in self-harm and even suicide. Conclusion: In view of the greater excitability of the developing nervous system, and its vulnerability to physical and psychological injuries, the review ends with an exhortation to consider the long-term consequences of childhood trauma, often underestimated or missed altogether when faced with adults suffering mental health problems.

Depression and Anxiety as Mediators of PTSD Symptom Clusters and Pain in Treatment-Seeking Canadian Forces Members and Veterans

INTRODUCTION

Chronic pain (CP) commonly presents alongside psychiatric conditions such as depression, PTSD, and generalized anxiety. The current study sought to better understand this complex relationship by determining whether anxiety and depression symptom severity mediated the relationship between DSM-5 PTSD symptom clusters and pain symptoms in a sample of 663 Canadian Armed Forces (CAF) personnel and veterans seeking treatment for mental health conditions.

MATERIALS AND METHODS

Generalized anxiety disorder, depression, and PTSD symptom severity were measured using self-report scales provided as part of a standard intake protocol. Pain symptoms were measured using the Bodily Pain subscale of the SF-36 (SF-36 BPS). Linear regressions were used to explore the relationship between PTSD symptom clusters, depression, anxiety, and pain. Bootstrapped resampling analyses were employed to test mediation effects.

RESULTS

The average SF-36 BPS score in this sample was 36.6, nearly 1.5 SDs below the population health status, enforcing the salience of pain symptoms as a concern for veterans and CAF seeking treatment for military-related psychiatric conditions. The effects of PTSD symptom clusters avoidance, negative mood and cognitions, and arousal on pain were fully mediated by anxiety and depression severity. However, the effect of intrusion on pain was not mediated by depression and only partly mediated by anxiety.

CONCLUSION

Findings emphasize the importance of including anxiety and depression in models of PTSD and pain, particularly in samples where psychiatric comorbidity is high. Clinically, results highlight the need for improved treatment regimens that address pain symptoms alongside common psychiatric comorbidities.

The relevance of post-traumatic stress disorder as a moderator of the relationship between experience of violent or sexual assault and opioid use in adulthood

BACKGROUND

Past research has indicated that individuals suffering from post-traumatic stress disorder (PTSD) may demonstrate increased sensitivity to stress exposure following onset of the disorder. Thus, having PTSD may amplify the effects of subsequent stressors. This has been found to be relevant in some forms of substance use but relationships between PTSD, new stress and opioid use specifically has not been examined.

AIMS

To explore interactions between PTSD, new victimisation and opioid use and test the hypothesis that PTSD will moderate any victimisation-opioid use relationship.

METHODS

The pathways to desistance data were used in analyses. A series of logistic regression models were used to test both direct effects of victimisation and PTSD on opioid use and interactions between them.

RESULTS

The sample was comprised of a male majority (male N = 1,170; female N = 184). Results indicated that neither PTSD nor victimisation were significant predictors of opioid use. PTSD was found to moderate the relationship between victimisation and opioid use in the hypothesised manner.

CONCLUSIONS

There may be clinical implications of these results relating to both inpatient and outpatient treatment. Regular trauma screening, additional victims' services and trauma-informed care may help to reduce the risk of opioid use among individuals suffering from PTSD.

Do somatic symptoms relate to PTSD and gender after earthquake exposure? A cross-sectional study on young adult survivors in Italy

OBJECTIVE

Increasing evidence confirms a strict relationship between mental disorders and physical health. Particularly, stressful life events and post-traumatic stress disorder (PTSD) have been closely correlated with various physical disorders and somatic symptoms, such as chronic pain, gastrointestinal disorders, and headaches. The aim of this study was to investigate the emergence of somatic symptoms in a sample of young adult survivors 21 months after exposure to the L'Aquila 2009 earthquake, with particular attention to PTSD and gender impact.

METHODS

Four hundred and fifty high-school senior students (253 male and 197 female) exposed to the 2009 L'Aquila earthquake, 21 months earlier, were enrolled and evaluated by the Trauma and Loss Spectrum Self-Report (TALS-SR), for symptomatological PTSD, and the Mood Spectrum Self-Report-Lifetime Version (MOODS-SR) "rhythmicity and vegetative functions" domain, for somatic symptoms.

RESULTS

Significantly higher rates of endorsement of the MOODS-SR somatic symptoms emerged in survivors with PTSD compared to those without. Females reported higher rates of endorsement of at least one MOODS-SR somatic symptom compared to males; however, a Decision Tree model and a two-way analysis of variance model confirmed a significant effect of PTSD only. A multivariate logistical regression showed a significant association between the presence of at least one MOOD-SR somatic symptom and re-experiencing and maladaptive coping TALS-SR domains.

CONCLUSION

This study corroborates a relevant impact of symptomatological PTSD, across both the genders, on somatic symptoms occurring in young adults after months from exposure to a massive earthquake.

Childhood Trauma Predicts Cancer Treatment-Related Pain in Breast Cancer Survivors

BACKGROUND

Childhood trauma has been linked to neuropathic pain in noncancer populations, but its relationship with cancer treatment-related neuropathic pain is unknown.

OBJECTIVE

This secondary data analysis of a prospective, longitudinal, observational study aimed to explore the relationship of childhood trauma experience with pain severity, pain interference, and neuropathic symptom severity (NSS) 12 months after surgery in women receiving treatment for stage 0 to III breast cancer.

METHODS

Women (N = 44) recruited from a comprehensive cancer center self-reported childhood trauma experience, pain severity, pain interference, NSS, co-occurring symptoms, and pain beliefs via questionnaires. Descriptive statistics were used to describe childhood trauma experience. Linear regression was used to model childhood trauma and other predictors on pain variables 12 months after surgery.

RESULTS

Childhood trauma predicted pain severity and pain interference 12 months after surgery (P < .05), as did baseline pain severities and helplessness-pain catastrophizing. Age predicted only NSS. Together, the best models predicted 31.6% to 40.9% of the variance in pain severities at 12 months (P < .001).

CONCLUSIONS

Childhood trauma exposure was a significant predictor of pain 12 months after breast cancer surgery and adjuvant treatment. Younger and helplessness-pain catastrophizing women are also at risk. Research is needed to identify preventive neuropathic pain interventions for high-risk women.

IMPLICATIONS FOR PRACTICE

Women receiving breast cancer treatment should proactively be assessed for childhood trauma history, possibly by using discreet previsit questionnaires. Childhood trauma survivors may be at high risk for poor pain outcomes and may benefit from tailored pain interventions.

Post-Traumatic Stress Disorder Symptoms Contribute to Worse Pain and Health Outcomes in Veterans With PTSD Compared to Those Without: A Systematic Review With Meta-Analysis

INTRODUCTION

Post-traumatic stress disorder (PTSD) and chronic pain are frequently co-morbid conditions in the U.S. veteran population. Although several theories about the cause of increased pain prevalence in individuals with PTSD have been presented, no synthesis of primary data informing the impact of co-morbid PTSD and pain has been completed. The purpose of this study was to systematically review the literature and quantify disability, function, and pain-related beliefs and outcomes in veterans with PTSD compared to veterans without PTSD.

MATERIALS AND METHODS

A systematic search of three electronic databases was conducted. Inclusion criteria required pain-related comparison of veterans with PTSD to those without PTSD. Primary outcome measures and standardized mean differences (SMDs) were assessed for pain, function, disability, pain beliefs, and healthcare utilization using a random effects model.

RESULTS

20 original research studies met inclusion criteria and were assessed for quality and outcomes of interest. The majority of studies were cross-sectional. Veterans with PTSD and pain demonstrated higher pain (SMD = 0.58, 95% CI 0.28-0.89), disability (SMD = 0.52, 95%CI 0.33-0.71), depression (SMD = 1.40, 95%CI 1.2-1.6), catastrophizing beliefs (SMD = 0.95, 95% CI 0.69-1.2), sleep disturbance (SMD = 0.80, 95% CI 0.57-1.02), and healthcare utilization; they had lower function (SMD = 0.41, 95% CI 0.25-0.56) and pain self-efficacy (SMD = 0.77, 95% CI 0.55-0.99) compared to veterans without PTSD.

CONCLUSION

In veterans with chronic pain, PTSD symptomology has a large effect for many negative health-related outcomes. This review supports the need for clinicians to screen and understand the effects of PTSD symptoms on patients with pain. Clinicians should recognize that veterans with PTSD and pain likely have elevated pain catastrophizing beliefs and decreased self-efficacy that should be targeted for intervention.

Yoga for warriors: An intervention for veterans with comorbid chronic pain and PTSD

OBJECTIVE

Comorbid chronic pain and posttraumatic stress disorder (PTSD) is common in veterans; this comorbidity is associated with increased severity and poorer prognosis when compared to each outcome alone. Yoga has been shown to be effective for chronic pain and promising for PTSD, but yoga for comorbid pain and PTSD has not been examined. This article offers empirical support for a yoga intervention for comorbid chronic pain and PTSD in a veteran population.

METHOD

Results are presented from a 4-year pilot yoga intervention for comorbid chronic pain and PTSD at a large, urban Veterans Affairs Medical Center. Based on the fear avoidance model of pain, the intervention used a cross-sectional, open-trial design with pre- and postmeasures. T test analyses were conducted on program completers (N = 49; out of 87 initially enrolled, 44% attrition rate), who were primarily African American (69%) and male (61%) and had a mean age of 51.41 years (SD = 11.32).

RESULTS

Results indicated trend-level reductions in overall PTSD symptoms, as measured by the PTSD Checklist for DSM-5 (p = .02, d = 0.38) and in symptom cluster scores of negative alterations of cognitions and mood (p = .03, d = 0.36) and arousal and reactivity (p = .03, d = 0.35). Veterans reported significant improvement in ability to participate in social activities (p < .001, d = 0.44) and significant reductions in kinesiophobia (fear of movement or physical activity; p < .001, d = 0.85). On a satisfaction measure with a range of 1 (quite dissatisfied) to 4 (extremely satisfied), the mean rating was 3.74 (SD = 0.33).

CONCLUSION

Yoga is a feasible and effective intervention for veterans with comorbid chronic pain and PTSD. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Comorbid chronic pain and post-traumatic stress disorder in UK veterans: a lot of theory but not enough evidence

INTRODUCTION

Chronic pain and post-traumatic stress disorder (PTSD) are strongly correlated in military veteran populations. The aim of this article is to review what is known about the comorbidity of the two conditions.

METHODS

A literature search was carried out to establish evidence for current explanatory models of why the two conditions frequently co-occur, the most appropriate treatments and current UK service provision for veterans and to identify gaps in research.

RESULTS

Chronic pain and PTSD share a number of features, yet the mechanisms behind their comorbidity are not well understood, and while each condition alone has extensive literature, there is limited evidence to support specific care and treatment for the two conditions simultaneously. In addition, there is currently no UK data for veterans with comorbid chronic pain and PTSD so it is not possible to gauge the numbers affected or to predict the numbers who will be affected in the future, and there appear to be no co-located services within the United Kingdom for the management of the two conditions simultaneously in this population.

CONCLUSION

This review highlights a paucity of evidence in all areas of comorbid chronic pain and PTSD. Further work needs to consider fully the nature of the event that led to the development of the two conditions and examine further the possible mechanisms involved, and clinics need to establish routine and systematic evaluations of how any interventions work in practice.

Moderated mediation for exercise maintenance in pain and posttraumatic stress disorder: A randomized trial

This study utilizes the Science of Behavior Change (SOBC) experimental medicine approach to evaluate the effects of a 3-month, individually prescribed progressive exercise training program on neurobiological, cognitive and motivational mechanisms by which our exercise-training paradigm may foster exercise maintenance. We will investigate hypothesized relationships between exercise-training associated augmentation of neuropeptide Y (NPY) system function and improvements in self-regulation and reward sensitivity-cognitive control and motivational processes posited to promote self-efficacy and intrinsic motivation, which have been shown to predict exercise maintenance. This study will recruit Veterans with chronic low back pain and posttraumatic stress disorder (PTSD). Procedures include a baseline, acute cardiopulmonary exercise challenge assessment that will inform the exercise prescription for a 12-week progressive exercise training program comprised of three 45-minute aerobic exercise sessions per week-all of which will be supervised by an exercise physiologist. Additionally, a week-7 and week-14 exercise challenge assessment will track changes in NPY system function and the variables of interest. We hypothesize that increases in the capacity to release NPY in response to acute exercise testing will be associated with improvements in self-regulation and reward sensitivity, which will in turn be associated with self-efficacy and intrinsic motivation to maintain regular exercise. Ninety participants will be randomized either to the "active exercise training condition" or to the "wait list symptom monitoring condition". The study aims to demonstrate the feasibility of procedures and elucidate mechanisms relevant to developing individually prescribed, motivationally based exercise regimens to reduce negative consequences of PTSD and low back pain over the long-term. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

How are pain and traumatic stress symptoms related in acute whiplash-associated disorders? An investigation of the role of pain-related fear in a daily diary study

Comorbidity of pain and posttraumatic stress disorder is well recognized, but the reason for this association is unclear. This study investigated the direction of the relationship between pain and traumatic stress and the role that pain-related fear plays, for patients with acute whiplash-associated disorder. Participants (n = 99) used an electronic diary to record hourly ratings of pain, traumatic stress, and fear of pain (FOP) symptoms over a day. Relationships between pain, traumatic stress, and pain-related fear symptoms were investigated through multilevel models including variables lagged by 1 hour. Traumatic stress was associated with previous pain, even after controlling for previous traumatic stress and current pain; current pain was not associated with previous traumatic stress. The relationship between traumatic stress and previous pain became negligible after controlling for FOP, except for traumatic stress symptoms of hyperarousal that were driven directly by pain. Overall, these results support a pain primacy model, and suggest that pain-related fear is important in the maintenance and development of comorbid pain and traumatic stress symptoms. They also confirm that traumatic stress symptoms of hyperarousal are central in this relationship. Differences between this study and others that reported mutual maintenance can be understood in terms of different stages of whiplash-associated disorder and different intervals between repeated measurements. Traumatic stress may affect pain over longer time intervals than measured in this study. Future research could explore how relationships between traumatic stress symptoms, pain, and FOP change over time, and whether previous experiences of traumatic stress influence these relationships.

trans-Resveratrol ameliorates anxiety-like behaviors and neuropathic pain in mouse model of post-traumatic stress disorder

BACKGROUND

trans-Resveratrol has been extensively investigated for its anti-inflammatory, antioxidant, and anti-psychiatric properties. However, whether it could rescue posttraumatic stress disorder-like stress-induced pain abnormality is unknown.

AIM

The present study examined the effects of trans-resveratrol on anxiety-like behavior and neuropathic pain induced by single-prolonged stress, which is a classical animal model for mimicking posttraumatic stress disorder.

METHODS

The single-prolonged stress-induced anxiety-like behavior and pain response were detected by the novelty suppressed feeding, marble burying, locomotor activity, von Frey, and acetone-induced cold allodynia tests in mice. The serum corticosterone levels and glucocorticoid receptor, protein kinase A, phosphorylated cAMP response element binding protein, and brain-derived neurotrophic factor expression were detected by enzyme-linked immunosorbent assay and immunoblot analyses.

RESULTS

trans-Resveratrol reversed single-prolonged stress-induced increased latency to feed and the number of marbles buried in the novelty suppressed feeding and marble burying tests, but did not significantly influence locomotion distance in the locomotor activity test. trans-Resveratrol also reversed single-prolonged stress-induced cold and mechanical allodynia. Moreover, single-prolonged stress induced abnormality in the limbic hypothalamus-pituitary-adrenal axis was reversed by trans-resveratrol, as evidenced by the fact that trans-resveratrol reversed the differential expression of glucocorticoid receptor in the anxiety- and pain-related regions. In addition, trans-resveratrol increased protein kinase A, phosphorylated cAMP response element binding protein, and brain-derived neurotrophic factor levels, which were decreased in mice subjected to single-prolonged stress.

CONCLUSIONS

These results provide compelling evidence that trans-resveratrol protects neurons against posttraumatic stress disorder-like stress insults through regulation of limbic hypothalamus-pituitary-adrenal axis function and activation of downstream neuroprotective molecules such as protein kinase A, phosphorylated cAMP response element binding protein, and brain-derived neurotrophic factor expression.

Targeting the PAC1 Receptor for Neurological and Metabolic Disorders

The pituitary adenylate cyclase-activating polypeptide (PACAP)-selective PAC1 receptor (PAC1R, ADCYAP1R1) is a member of the vasoactive intestinal peptide (VIP)/secretin/glucagon family of G protein-coupled receptors (GPCRs). PAC1R has been shown to play crucial roles in the central and peripheral nervous systems. The activation of PAC1R initiates diverse downstream signal transduction pathways, including adenylyl cyclase, phospholipase C, MEK/ERK, and Akt pathways that regulate a number of physiological systems to maintain functional homeostasis. Accordingly, at times of tissue injury or insult, PACAP/PAC1R activation of these pathways can be trophic to blunt or delay apoptotic events and enhance cell survival. Enhancing PAC1R signaling under these conditions has the potential to mitigate cellular damages associated with cerebrovascular trauma (including stroke), neurodegeneration (such as Parkinson's and Alzheimer's disease), or peripheral organ insults. Conversely, maladaptive PACAP/PAC1R signaling has been implicated in a number of disorders, including stressrelated psychopathologies (i.e., depression, posttraumatic stress disorder, and related abnormalities), chronic pain and migraine, and metabolic diseases; abrogating PAC1R signaling under these pathological conditions represent opportunities for therapeutic intervention. Given the diverse PAC1R-mediated biological activities, the receptor has emerged as a relevant pharmaceutical target. In this review, we first describe the current knowledge regarding the molecular structure, dynamics, and function of PAC1R. Then, we discuss the roles of PACAP and PAC1R in the activation of a variety of signaling cascades related to the physiology and diseases of the nervous system. Lastly, we examine current drug design and development of peptides and small molecules targeting PAC1R based on a number of structure- activity relationship studies and key pharmacophore elements. At present, the rational design of PAC1R-selective peptide or small-molecule therapeutics is largely hindered by the lack of structural information regarding PAC1R activation mechanisms, the PACAP-PAC1R interface, and the core segments involved in receptor activation. Understanding the molecular basis governing the PACAP interactions with its different cognate receptors will undoubtedly provide a basis for the development and/or refinement of receptor-selective therapeutics.

Post-traumatic Stress Disorder Symptoms are Associated With Incident Chronic Back Pain: A Longitudinal Twin Study of Older Male Veterans

STUDY DESIGN

A longitudinal cotwin control study of the Vietnam Era Twin Registry.

OBJECTIVE

The aim of this study was to examine the association of post-traumatic stress disorder (PTSD) symptoms with incident chronic back pain (CBP), while controlling for genetic factors and early family environment.

SUMMARY OF BACKGROUND DATA

It is unknown whether PTSD symptoms are associated with an increased incidence of CBP.

METHODS

In 2010 to 2012, a baseline survey was undertaken as part of a large-scale study of PTSD. Study participants completed the PTSD Symptom Checklist (PCL) and a self-report measure of CBP. In 2015 to 2017, a follow-up survey was sent to all 171 monozygotic (MZ) twin pairs (342 individuals) where both cotwins had no history of CBP at baseline, but only one cotwin in the pair met criteria for having current PTSD symptoms (one twin with PCL <30 and the cotwin with PCL ≥30). No other inclusion/exclusion criteria were applied. CBP at 5-year follow-up was defined as back pain of duration ≥3 months in the low back or mid/upper back. Covariates included age, race, education, income, Veterans Affairs health care use, disability compensation, smoking, body mass index, and depression. Statistical analysis estimated the cumulative incidence of CBP according to baseline PTSD symptoms. Risk ratios (RRs) and 95% confidence intervals (95% CIs) were estimated in matched-pair cotwin control analyses adjusting for familial factors.

RESULTS

Among 227 males completing 5-year follow-up, including 91 MZ twin pairs, the mean age was 62 years. Five-year incidence of CBP in those without and with baseline PTSD symptoms was 40% and 60%, respectively. Baseline PTSD symptoms were significantly associated with incident CBP in crude and multivariable-adjusted within-pair analyses (RR 1.6, 95% CI 1.2-2.1; P = 0.002).

CONCLUSION

PTSD symptoms were associated with an increased incidence of CBP, without confounding by genetic factors or early family environment. PTSD symptoms may be a modifiable risk factor for prevention of CBP.

LEVEL OF EVIDENCE

3.

Development of a pain neuroscience education program for post-traumatic stress disorder and pain

Introduction: Individuals with co-morbid post-traumatic stress disorder (PTSD) and pain have higher disability, pain, and pain catastrophizing beliefs than patients without PTSD. Pain neuroscience education (PNE) may be an effective tool to help those with PTSD and pain reduce maladaptive beliefs about pain. The purpose of this paper is to report the development and evaluation of a PNE curriculum for participants with PTSD and pain. Methods: After writing an initial draft of PNE for PTSD and pain, a panel of medical experts in PNE, PTSD, and rehabilitation reviewed the booklet. After addressing recommendations from the medical panel (n = 29), individuals with (n = 13) and without (n = 20) PTSD reviewed the booklet. Results: Overall, 89% of participants recommended the PNE booklet and 90% thought it would help patients with PTSD and pain. Although patients with PTSD rated the PNE booklet more critically than other participants, a particular support group (n = 4) rated the PNE booklet significantly different (p < .05) than remaining participants with PTSD (n = 9). Individuals with PTSD and pain were able to comprehend the PNE booklet at a comparable rate to an expert medical panel and participants without PTSD after adjusting for education levels (p = .12). Conclusions: Many patients with PTSD and pain avoid painful activities because they believe they are harmful. This research demonstrates that individuals with PTSD and pain can comprehend PNE that challenges these beliefs. The PNE curriculum developed by this research may provide a logical explanation for the link between PTSD symptoms and pain and should be tested for clinical effectiveness.

Tobacco dependence is associated with increased risk for multi-morbid clustering of posttraumatic stress disorder, depressive disorder, and pain among post-9/11 deployed veterans

RATIONALE

Tobacco use is highly prevalent among individuals with posttraumatic stress disorder (PTSD), depressive disorders, and pain. Research has revealed pairwise relationships among these conditions but has not examined more complex relationships that may influence symptom severity, chronicity, and treatment outcome.

OBJECTIVE

To examine the clustering of current PTSD, depressive disorders, and clinically significant pain according to current tobacco use and dependence among post-9/11 deployed veterans.

METHODS

Logistic regression was used to examine the clustering of these conditions in relationship to current tobacco use/dependence, while adjusting for age and total combat exposure, in 343 post-9/11 deployed veterans enrolled in the Translational Research Center for TBI and Stress Disorders (TRACTS) cohort (Mage = 32.1 + 8.3 years; 38% current tobacco use; 25% low and 12% moderate/high tobacco dependence).

RESULTS

A three-way clustering of PTSD, depressive disorder, and pain was more likely than any single or pairwise combination of these conditions in moderate/high tobacco-dependent veterans compared to tobacco non-users (adjusted ORs = 3.50 to 4.18). This multi-morbidity cluster also was associated with increased PTSD severity.

CONCLUSIONS

Moderate to high dependence on tobacco is associated with substantially increased clustering of PTSD, depression, and clinically significant pain in veterans. Research examining synergistic interactions among these conditions, biological vulnerabilities shared among them, and the direct impact of tobacco use on the pathophysiology of PTSD, depression, and pain is needed. The results of such work may spur development of more effective integrated treatments to reduce the negative impact of these multi-morbid conditions on veterans' wellbeing and long-term health.

The Impact of Psychological Interventions on Posttraumatic Stress Disorder and Pain Symptoms: A Systematic Review and Meta-Analysis

OBJECTIVES

Posttraumatic stress disorder (PTSD) and pain often co-occur, introducing clinical challenges and economic burden. Psychological treatments are considered effective for each condition, yet it is not known which therapies have the potential to concurrently address PTSD and pain-related symptoms.

MATERIALS AND METHODS

To conduct a systematic review and meta-analysis, databases were searched for articles published between January 2007 and December 2017 describing results from clinical trials of interventions addressing PTSD and pain-related symptoms in adults. Two independent reviewers finalized data extraction and risk of bias assessments. A random-effects model was used for meta-analysis and to calculate pooled and subgroup effect sizes (ESs) of psychological-only (single modality) and multimodal interventions.

RESULTS

Eighteen trials (7 uncontrolled, 11 randomized controlled trials, RCTs), totaling 1583 participants, were included in the systematic review. RCT intervention types included exposure-based, cognitive-behavioral, and mindfulness-based therapies. Data from 10 RCTs (N=1, 35) were available for meta-analysis, which demonstrated moderate effect for reduced PTSD severity (ES=-0.55, confidence interval [CI]: -0.83, -0.26) and nonsignificant effect for pain intensity (ES=-0.14, CI: -0.43, 0.15) and pain interference (ES=-0.07, CI: -0.35, 0.20) outcomes. Findings from uncontrolled trials supported meta-analytic results from RCTs. Using GRADE assessment, the quality of evidence was deemed as moderate for RCTs and low for non-RCTs.

DISCUSSION

Findings indicated that the majority of the interventions appeared to have a greater impact on reducing PTSD rather than pain-related symptoms. There remains a need to further develop interventions that consistently impact PTSD and pain-related outcomes when these 2 conditions co-occur.

Prevalence and Correlates of Disability Among a Sample of Victimized Women on Probation and Parole

The purpose of this exploratory study was to establish the prevalence of disability as measured by self-reported Social Security Disability Insurance (SSDI) receipt among a sample of women on probation and parole who have experienced interpersonal victimization in childhood and/or adulthood. Women receiving SSDI were more likely to be older, White, to live alone, and to score lower on measures of social support compared to women not receiving SSDI. SSDI recipients were also more likely to report poorer health, chronic pain, and more frequent health care service utilization. High rates of adverse childhood experiences, rape, adult victimization, and an overall greater severity of post-traumatic stress disorder symptomatology were observed for women receiving SSDI. Groups had similar overall mental health profiles and diverged primarily on trauma variables. Findings support the need for trauma-informed care and highlight the possibility that some criminal justice system-involved women likely qualify for SSDI, yet are not receiving it.

The stress regulator FKBP51: a novel and promising druggable target for the treatment of persistent pain states across sexes

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Pharmacological blockade of FKBP51 can reduce established persistent pain states across sexes.

It is well established that FKBP51 regulates the stress system by modulating the sensitivity of the glucocorticoid receptor to stress hormones. Recently, we have demonstrated that FKBP51 also drives long-term inflammatory pain states in male mice by modulating glucocorticoid signalling at spinal cord level. Here, we explored the potential of FKBP51 as a new pharmacological target for the treatment of persistent pain across the sexes. First, we demonstrated that FKBP51 regulates long-term pain states of different aetiologies independently of sex. Deletion of FKBP51 reduced the mechanical hypersensitivity seen in joint inflammatory and neuropathic pain states in female and male mice. Furthermore, FKBP51 deletion also reduced the hypersensitivity seen in a translational model of chemotherapy-induced pain. Interestingly, these 3 pain states were associated with changes in glucocorticoid signalling, as indicated by the increased expression, at spinal cord level, of the glucocorticoid receptor isoform associated with glucocorticoid resistance, GR_β, and increased levels of plasma corticosterone. These pain states were also accompanied by an upregulation of interleukin-6 in the spinal cord. Crucially, we were able to pharmacologically reduce the severity of the mechanical hypersensitivity seen in these 3 models of persistent pain with the unique FKBP51 ligand SAFit2. When SAFit2 was combined with a state-of-the-art vesicular phospholipid gel formulation for slow release, a single injection of SAFit2 offered pain relief for at least 7 days. We therefore propose the pharmacological blockade of FKBP51 as a new approach for the treatment of persistent pain across sexes, likely in humans as well as rodents.

Do post-traumatic pain and post-traumatic stress symptomatology mutually maintain each other? A systematic review of cross-lagged studies

After traumatic exposure, individuals are at risk of developing symptoms of both pain and post-traumatic stress disorder (PTSD). Theory and research suggest a complex and potentially mutually maintaining relationship between these symptomatologies. However, findings are inconsistent and the applied methods are not always well suited for testing mutual maintenance. Cross-lagged designs can provide valuable insights into such temporal associations, but there is a need for a systematic review to assist clinicians and researchers in understanding the nature of the relationship. Thus, the aim of this systematic review was to identify, critically appraise, and synthesize results from cross-lagged studies on pain and PTSD symptomatology to assess the evidence for longitudinal reciprocity and potential mediators. Systematic searches resulted in 7 eligible studies that were deemed of acceptable quality with moderate risk of bias using the cohort study checklist from Scottish Intercollegiate Guidelines Network. Furthermore, synthesis of significant pathways in the cross-lagged models showed inconsistent evidence of both bidirectional and unidirectional interaction patterns between pain and PTSD symptomatology across time, hence not uniformly supporting the theoretical framework of mutual maintenance. In addition, the synthesis suggested that hyperarousal and intrusion symptoms may be of particular importance in these cross-lagged relationships, while there was inconclusive evidence of catastrophizing as a mediator. In conclusion, the findings suggest an entangled, but not necessarily mutually maintaining relationship between pain and PTSD symptomatology. However, major variations in findings and methodologies complicated synthesis, prompting careful interpretation and heightening the likelihood that future high-quality studies will change these conclusions.

Systematic review with meta-analysis: The association between post-traumatic stress disorder and irritable bowel syndrome

BACKGROUND AND AIM

Post-traumatic stress disorder (PTSD) is a psychiatric condition characterized by symptoms of hyperarousal and hypervigilance. Increasing research on the "gut-brain" axis (bidirectional signaling between the gut and the brain) has drawn links between PTSD and irritable bowel syndrome (IBS), an exceedingly common yet incompletely understood gastrointestinal condition. This meta-analysis thus aimed to examine the body of evidence and extent of association of PTSD with IBS.

METHODS

Using the keywords [early abuse OR childhood abuse OR violence OR trauma OR PTSD] AND [irritable bowel syndrome or IBS], a preliminary search on the PubMed, Medline, Embase, ScienceDirect, PsychINFO, Web of Science, and Google Scholar databases yielded 11,257 papers published in English between January 1, 1988, and May 1, 2018. Of these, only eight studies were included in the final meta-analysis.

RESULTS

The eight studies (four cross-sectional and four cohort) contained a total of 648,375 subjects. Most studies were from the USA and conducted on army veterans. The funnel plot revealed a roughly symmetrical distribution of studies, and Egger test was not significant for publication bias (P = 0.583). Random-effects meta-analysis found PTSD to be a significant risk factor for IBS (pooled odds ratio 2.80, 95% confidence interval: 2.06 to 3.54, P < 0.001).

CONCLUSIONS

Overall, PTSD is associated with an increased likelihood of IBS. This is the first meta-analysis to specifically examine the association between PTSD and IBS, and it provides insights into the probable (patho)physiology and management of IBS, supporting a holistic consideration of the psychosocial aspects of IBS and further research into effective multi-modal therapeutics.