Specific Pain Complaints in Iraq and Afghanistan Veterans Screening Positive for Post-Traumatic Stress Disorder

Disentangling the effects of PTSD from Gulf War Illness in male veterans via a systems-wide analysis of immune cell, cytokine, and symptom measures

BACKGROUND

One-third of veterans returning from the 1990-1991 Gulf War reported a myriad of symptoms including cognitive dysfunction, skin rashes, musculoskeletal discomfort, and fatigue. This symptom cluster is now referred to as Gulf War Illness (GWI). As the underlying mechanisms of GWI have yet to be fully elucidated, diagnosis and treatment are based on symptomatic presentation. One confounding factor tied to the illness is the high presence of post-traumatic stress disorder (PTSD). Previous research efforts have demonstrated that both GWI and PTSD are associated with immunological dysfunction. As such, this research endeavor aimed to provide insight into the complex relationship between GWI symptoms, cytokine presence, and immune cell populations to pinpoint the impact of PTSD on these measures in GWI.

METHODS

Symptom measures were gathered through the Multidimensional fatigue inventory (MFI) and 36-item short form health survey (SF-36) scales and biological measures were obtained through cytokine & cytometry analysis. Subgrouping was conducted using Davidson Trauma Scale scores and the Structured Clinical Interview for Diagnostic and statistical manual of mental disorders (DSM)-5, into GWI with high probability of PTSD symptoms (GWIH) and GWI with low probability of PTSD symptoms (GWIL). Data was analyzed using Analysis of variance (ANOVA) statistical analysis along with correlation graph analysis. We mapped correlations between immune cells and cytokine signaling measures, hormones and GWI symptom measures to identify patterns in regulation between the GWIH, GWIL, and healthy control groups.

RESULTS

GWI with comorbid PTSD symptoms resulted in poorer health outcomes compared with both Healthy control (HC) and the GWIL subgroup. Significant differences were found in basophil levels of GWI compared with HC at peak exercise regardless of PTSD symptom comorbidity (ANOVA F = 4.7, P = 0.01,) indicating its potential usage as a biomarker for general GWI from control. While the unique identification of GWI with PTSD symptoms was less clear, the GWIL subgroup was found to be delineated from both GWIH and HC on measures of IL-15 across an exercise challenge (ANOVA F > 3.75, P < 0.03). Additional differences in natural killer (NK) cell numbers and function highlight IL-15 as a potential biomarker of GWI in the absence of PTSD symptoms.

CONCLUSION

We conclude that disentangling GWI and PTSD by defining trauma-based subgroups may aid in the identification of unique GWI biosignatures that can help to improve diagnosis and target treatment of GWI more effectively.

Yoga Plus Mantram Repetition to Reduce Chronic Pain in Veterans With Post-Traumatic Stress Disorder: A Feasibility Trial

Background

Veterans with post-traumatic stress disorder (PTSD) are more likely to report chronic pain than veterans without PTSD. Yoga has been shown to reduce both chronic pain and PTSD symptoms in clinical trials. The goal of our study was to assess the feasibility and acceptability of conducting a randomized controlled trial (RCT) that combined yoga and mantram repetition (Yoga + MR) into one program for military veterans with both chronic pain and PTSD.

Methods

In this feasibility RCT, 27 veterans were randomized to either Yoga + MR or a relaxation intervention. Due to the COVID-19 pandemic, in-person recruitment, assessments, and intervention attendance were re-evaluated. Although remote delivery of aspects of the study were utilized, interventions were delivered in-person. Feasibility benchmarks met included full recruitment in 12 months or less, 75%+ retention at initial follow-up assessment, 50%+ attendance rate, and 75%+ of participants satisfied with the interventions.

Results

The sample was racially and ethnically diverse, and 15% of participants were women. Participant recruitment lasted approximately 11 months. Out of 32 participants initially randomized, two participants asked to be dropped from the study and three did not meet PTSD symptom criteria. For the remaining 27 participants, retention rates were 85% at 12 weeks and 81% at 18 weeks. Participants attended 66% of in-person yoga and 55% of in-person relaxation sessions. Satisfaction was high, with 100% of yoga participants and 75%/88% of relaxation participants agreeing or strongly agreeing they were satisfied with the intervention/instructors. After 12 weeks (end of intervention), Yoga + MR participants reported reduced back-pain related disability (primary outcome), reduced alcohol use, reduced fatigue, and increased quality of life, while relaxation group participants reported reductions in pain severity, PTSD symptoms, and fatigue.

Conclusions

Amidst many research challenges during the pandemic, recruitment, retention, and efficacy results from this feasibility trial support advancement to a larger RCT to study Yoga + MR for chronic pain and PTSD.

Pain and Psychological Outcomes Among Iraq and Afghanistan Veterans with Chronic Pain and PTSD: ESCAPE Trial Longitudinal Results

Objective

To compare pain and psychological outcomes in veterans with chronic musculoskeletal pain and comorbid post-traumatic stress disorder (PTSD) or pain alone and to determine if veterans with comorbidity respond differently to a stepped-care intervention than those with pain alone.

Design

Secondary analysis of data from the Evaluation of Stepped Care for Chronic Pain (ESCAPE) trial.

Setting

Six Veterans Health Affairs clinics.

Subjects

Iraq and Afghanistan veterans (N = 222) with chronic musculoskeletal pain.

Methods

Longitudinal analysis of veterans with chronic musculoskeletal pain and PTSD or pain alone and available baseline and nine-month trial data. Participants randomized to either usual care or a stepped-care intervention were analyzed. The pain–PTSD comorbidity group screened positive for PTSD and had a PTSD Checklist–Civilian score ≥41 at baseline.

Results

T tests demonstrated statistically significant differences and worse outcomes on pain severity, pain cognitions, and psychological outcomes in veterans with comorbid pain and PTSD compared with those with pain alone. Analysis of covariance (ANCOVA) modeling change scores from baseline to nine months indicated no statistically significant differences, controlling for PTSD, on pain severity, pain centrality, or pain self-efficacy. Significant differences emerged for pain catastrophizing (t = 3.10, P &lt; 0.01), depression (t = 3.39, P &lt; 0.001), and anxiety (t = 3.80, P &lt; 0.001). The interaction between PTSD and the stepped-care intervention was not significant.

Conclusions

Veterans with the pain–PTSD comorbidity demonstrated worse pain and psychological outcomes than those with chronic pain alone. These findings indicate a more intense chronic pain experience for veterans when PTSD co-occurs with pain. PTSD did not lead to a differential response to a stepped-care intervention.

Posttraumatic stress disorder and somatic complaints: Contrasting Vietnam and OIF/OEF Veterans' experiences

OBJECTIVE

To replicate and expand upon the relationship of somatic symptoms and posttraumatic stress disorder (PTSD) by comparing symptoms among service eras in US Veterans.

METHOD

Data were collected from 226 Vietnam and 132 Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) Veterans who were referred to a Veterans Affairs (VA) hospital PTSD outpatient clinic between 2005 and 2013. Veterans were administered self-report inventories and a clinical interview to measure somatic symptoms and PTSD severity. A subset of Veterans (n=185) screening positive for PTSD were administered the Clinician Administered PTSD Scale (CAPS) to measure PTSD severity. Multiple moderated linear regressions were used to examine the influence of service era on the relationship between somatic and PTSD symptoms.

RESULTS

There were no significant differences between service eras in pain severity, pain interference, and total somatic symptoms reported. Vietnam Veterans were more likely to report limb/join pain (p<.05), fainting (p<.01), and shortness of breath (p<.001), whereas OIF/OEF Veterans were more likely to complain of headaches (p<.001). A significant interaction effect occurred between service era and dizziness (p<.05) and chest pain (p<.01), with OIF/OEF Veterans reporting higher levels of these symptoms significantly more likely than Vietnam Veterans to also experience more severe PTSD.

CONCLUSION

Findings are consistent with previous research demonstrating the relationship of somatic symptoms and PTSD across service eras but provide additional data concerning similarities and differences of somatic symptoms between eras. Potential explanations for observed service era differences in somatic symptoms are discussed.

Correlates of pain symptoms among Iraq and Afghanistan military personnel following combat-related blast exposure

Pain complaints are highly prevalent among military servicemembers and Veterans of the recent combat operations in Iraq and Afghanistan. The high comorbidity of pain with conditions such as posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI) underscores the importance of a greater understanding of factors associated with complex polytraumatic injuries among military personnel. The present study aimed to identify correlates of current pain among 201 U.S. military personnel who reported at least one blast experience during combat deployment (age [mean +/– standard deviation]: 27.20 +/– 7.58 yr). Theoretically derived subsets of variables were analyzed in successive hierarchical regression models to determine correlates of self-reported pain symptoms. Preliminary models evaluated demographic features, medical and injury characteristics (e.g., TBI classification), psychosocial history (e.g., trauma exposure), and psychiatric variables. A final model was then derived, in which older age, possible or probable mild TBI, depression symptoms, and PTSD re-experiencing symptoms emerged as significant correlates of pain. The findings further the understanding of polytrauma symptoms among military personnel by identifying specific patient characteristics and comorbidity patterns related to pain complaints. Increased awareness of demographic, psychiatric, or medical factors implicated in pain will enhance comprehensive clinical assessment and intervention efforts.

Comparison of operant escape and reflex tests of nociceptive sensitivity

Testing of reflexes such as flexion/withdrawal or licking/guarding is well established as the standard for evaluating nociceptive sensitivity and its modulation in preclinical investigations of laboratory animals. Concerns about this approach have been dismissed for practical reasons - reflex testing requires no training of the animals; it is simple to instrument; and responses are characterized by observers as latencies or thresholds for evocation. In order to evaluate this method, the present review summarizes a series of experiments in which reflex and operant escape responding are compared in normal animals and following surgical models of neuropathic pain or pharmacological intervention for pain. Particular attention is paid to relationships between reflex and escape responding and information on the pain sensitivity of normal human subjects or patients with pain. Numerous disparities between results for reflex and operant escape measures are described, but the results of operant testing are consistent with evidence from humans. Objective reasons are given for experimenters to choose between these and other methods of evaluating the nociceptive sensitivity of laboratory animals.

Longitudinal interactions of pain and posttraumatic stress disorder symptoms in U.S. Military service members following blast exposure

Military personnel returning from conflicts in Iraq and Afghanistan often endorse pain and posttraumatic stress disorder (PTSD) symptoms, either separately or concurrently. Associations between pain and PTSD symptoms may be further complicated by blast exposure from explosive munitions. Although many studies have reported on the prevalence and disability associated with polytraumatic injuries following combat, less is known about symptom maintenance over time. Accordingly, this study examined longitudinal interactive models of co-occurring pain and PTSD symptoms in a sample of 209 military personnel (mean age = 27.4 years, standard deviation = 7.6) who experienced combat-related blast exposure. Autoregressive cross-lagged analysis examined longitudinal associations between self-reported pain and PTSD symptoms over a 1-year period. The best-fitting covariate model indicated that pain and PTSD were significantly associated with one another across all assessment periods, χ² (3) = 3.66, P = .30, Tucker-Lewis index = .98, comparative fit index = 1.00, root mean squared error of approximation = .03. PTSD symptoms had a particularly strong influence on subsequent pain symptoms. The relationship between pain and PTSD symptoms is related to older age, race, and traumatic brain injury characteristics. Results further the understanding of complex injuries among military personnel and highlight the need for comprehensive assessment and rehabilitation efforts addressing the interdependence of pain and co-occurring mental health conditions.

PERSPECTIVE

This longitudinal study demonstrates that pain and PTSD symptoms strongly influence one another and interact across time. These findings have the potential to inform the integrative assessment and treatment of military personnel with polytrauma injuries and who are at risk for persistent deployment-related disorders.