Blast-related mild TBI: LIMBIC-CENC focused review with implications commentary.

BACKGROUND: A significant factor for the high prevalence of traumatic brain injury (TBI) among U.S. service members is their exposure to explosive munitions leading to blast-related TBI. Our understanding of the specific clinical effects of mild TBI having a component of blast mechanism remains limited compared to pure blunt mechanisms. OBJECTIVE: The purpose of this review is to provide a synopsis of clinical research findings on the long-term effects of blast-related mild TBI derived to date from the Long-Term Impact of Military-Relevant Brain Injury Consortium - Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC). METHODS: Publications on blast-related mild TBI from LIMBIC-CENC and the LIMBIC-CENC prospective longitudinal study (PLS) cohort were reviewed and their findings summarized. Findings from the broader literature on blast-related mild TBI that evaluate similar outcomes are additionally reviewed for a perspective on the state of the literature. RESULTS: The most consistent and compelling evidence for long-term effects of blast-related TBI is for poorer psychological health, greater healthcare utilization and disability levels, neuroimaging impacts on brain structure and function, and greater headache impact on daily life. To date, evidence for chronic cognitive performance deficits from blast-related mild TBI is limited, but futher research including crucial longitudinal data is needed. CONCLUSION: Commentary is provided on: how LIMBIC-CENC findings assimilate with the broader literature; ongoing research gaps alongside future research needs and priorities; how the scientific community can utilize the LIMBIC-CENC database for independent or collaborative research; and how the evidence from the clinical research should be assimilated into clinical practice.

The Functional Connectome and Long-Term Symptom Presentation Associated With Mild TBI and Blast Exposure in Combat Veterans.

Mild traumatic brain injury (TBI) sustained in a deployment environment (deployment TBI) can be associated with increased severity of long-term symptom presentation, despite the general expectation of full recovery from a single mild TBI. The heterogeneity in effects of Deployment TBI on the brain can be difficult for a case-control design to capture. The functional connectome of the brain is an approach robust to heterogeneity, that allows global measurement of effects using a common set of outcomes. The present study evaluates how differences in the functional connectome relate to remote symptom presentation following combat deployment and determines if deployment TBI, blast exposure, or posttraumatic stress disorder (PTSD) are associated with these neurological differences. Participants included 181 Iraq and Afghanistan combat-exposed veterans approximately 9.4 years since deployment. Structured clinical interviews provided diagnoses and characterization of TBI, blast exposure, and PTSD. Self-report measures provided characterization of long-term symptoms (psychiatric, behavioral health, and quality of life). Resting-state magnetoencephalography (MEG) was used to characterize the functional connectome of the brain individually for each participant. Linear regression identified factors contributing to symptom presentation including relevant covariates, connectome metrics, deployment TBI, blast exposure PTSD, and conditional relationships. Results identified unique contributions of aspects of the connectome to symptom presentation. Further, several conditional relationships were identified demonstrating that the connectome was related to outcomes only in the presence of deployment-related TBI (including blast-related TBI, primary blast TBI, and blast exposure). No conditional relationships were identified for PTSD; however, the main effect of PTSD on symptom presentation was significant for all models. These results demonstrate that the connectome captures aspects of brain function relevant to long-term symptom presentation, highlighting that deployment-related TBI influences symptom outcomes through a neurological pathway. These findings demonstrate that changes in the functional connectome associated with deployment-related TBI are relevant to symptom presentation over a decade past the injury event, providing a clear demonstration of a brain based mechanism of influence.

Research Letter: Characterizing Lifetime Mild TBI Exposure Among Female and Male Military Service Members and Veterans in the LIMBIC-CENC Study.

OBJECTIVE: To (1) characterize lifetime mild traumatic brain injury (TBI) exposures among male and female US military service members and Veterans (SMVs) and (2) evaluate sex-related differences in mild TBI exposures. SETTING: Clinical research laboratory. PARTICIPANTS: Participants were enrolled in the ongoing Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) Prospective Longitudinal Study. DESIGN: Cross-sectional. MAIN MEASURES: Lifetime history of mild TBI was measured via structured interview. All mild TBI characteristics were collected as part of this interview, including total lifetime number; environment (deployment vs. non-deployment); timing of injury (relative to military service and age); and mechanism of injury (blast-related vs. non-blast). RESULTS: Most participants (n = 2323; 87.5% male; 79.6% Veteran) reported ≥1 lifetime mild TBI (n = 1912; 82%), among whom, many reported ≥2 lifetime mild TBIs. Female SMVs reported fewer total lifetime mild TBIs than male participants (P < 0.001), including fewer deployment-related (P < 0.001) and non-deployment (P < 0.001) mild TBIs. There were significant sex differences for total number of mild TBIs sustained before (P = 0.005) and during (P < 0.001) military service but not after separation from military service (P = 0.99). Among participants with a lifetime history of mild TBI, female SMVs were less likely to report ≥2 mTBIs (P = 0.003); however, male SMVs were more likely to report a mild TBI during military service (P = 0.03), including combat-related mild TBI (P < 0.001) and mild TBI involving blast (P < 0.001). CONCLUSIONS: These findings inform clinical and research efforts related to mild TBI in US military SMVs. It may not be sufficient to simply measure the total number of mild TBIs when seeking to compare clinical outcomes related to mild TBI between sexes; rather, it is important to measure and account for the timing, environment, and mechanisms associated with mild TBIs sustained by female and male SMVs.

The Impact of Non-Pain Factors on Pain Interference Among U.S. Service Members and Veterans with Symptoms of Mild Traumatic Brain Injury.

U.S. Service members and Veterans (SM/V) experience elevated rates of traumatic brain injury (TBI), chronic pain, and other non-pain symptoms. However, the role of non-pain factors on pain interference levels remains unclear among SM/Vs, particularly those with a history of TBI. The primary objective of this study was to identify factors that differentiate high/low pain interference, given equivalent pain intensity among U.S. SM/V participating in the ongoing Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) national multi-center prospective longitudinal observational study. An explainable machine learning was used to identify key predictors of pain interference conditioned on equivalent pain intensity. The final sample consisted of n = 1,577 SM/Vs who were predominantly male (87%), and 83.6% had a history of mild TBI(s) (mTBI), while 16.4% were TBI negative controls. The sample was categorized according to pain interference level (Low: 19.9%, Moderate: 52.5%, and High: 27.6%). Both pain intensity scores and pain interference scores increased with the number of mTBIs (p < 0.001), and there was evidence of a dose response between the number of injuries and pain scores. Machine learning models identified fatigue and anxiety as the most important predictors of pain interference, whereas emotional control was protective. Partial dependence plots identified that marginal effects of fatigue and anxiety were associated with pain interference (p < 0.001), but the marginal effect of mTBI was not significant in models considering all variables (p > 0.05). Non-pain factors are associated with functional limitations and disability experience among SM/V with an mTBI history. The functional effects of pain may be mediated through multiple other factors. Pain is a multi-dimensional experience that may benefit most from holistic treatment approaches that target comorbidities and build supports that promote recovery.

Neuropsychological Profiles of Deployment-Related Mild Traumatic Brain Injury: A LIMBIC-CENC Study.

BACKGROUND AND OBJECTIVES: Traumatic brain injury (TBI) is a concern for US service members and veterans (SMV), leading to heterogeneous psychological and cognitive outcomes. We sought to identify neuropsychological profiles of mild TBI (mTBI) and posttraumatic stress disorder (PTSD) among the largest SMV sample to date. METHODS: We analyzed cross-sectional baseline data from SMV with prior combat deployments enrolled in the ongoing Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium prospective longitudinal study. Latent profile analysis identified symptom profiles using 35 indicators, including physical symptoms, depression, quality of life, sleep quality, postconcussive symptoms, and cognitive performance. It is important to note that the profiles were determined independently of mTBI and probable PTSD status. After profile identification, we examined associations between demographic variables, mTBI characteristics, and PTSD symptoms with symptom profile membership. RESULTS: The analytic sample included 1,659 SMV (mean age 41.1 ± 10.0 years; 87% male); among them 29% (n = 480) had a history of non-deployment-related mTBI only, 14% (n = 239) had deployment-related mTBI only, 36% (n = 602) had both non-deployment and deployment-related mTBI, and 30% (n = 497) met criteria for probable PTSD. A 6-profile model had the best fit, with separation on all indicators (p < 0.001). The model revealed distinct neuropsychological profiles, representing a combination of 3 self-reported functioning patterns: high (HS), moderate (MS), and low (LS), and 2 cognitive performance patterns: high (HC) and low (LC). The profiles were (1) HS/HC: n=301, 18.1%; (2) HS/LC: n=294, 17.7%; (3) MS/HC: n=359, 21.6%; (4) MS/LC: n=316, 19.0%; (5) LS/HC: n=228, 13.7%; and (6) LS/LC: n=161, 9.7%. SMV with deployment-related mTBI tended to be grouped into lower functioning profiles and were more likely to meet criteria for probable PTSD. Conversely, SMV with no mTBI exposure or non-deployment-related mTBI were clustered in higher functioning profiles and had a lower likelihood of meeting criteria for probable PTSD. DISCUSSION: Findings suggest varied symptom and functional profiles in SMV, influenced by injury context and probable PTSD comorbidity. Despite diagnostic challenges, comprehensive assessment of functioning and cognition can detect subtle differences related to mTBI and PTSD, revealing distinct neuropsychological profiles. Prioritizing early treatment based on these profiles may improve prognostication and support efficient recovery.

Comparing effectiveness of residential versus intensive virtual treatment for veterans with posttraumatic stress disorder.

OBJECTIVE: During the COVID-19 pandemic, restrictions imposed on residential treatment programs necessitated rapid implementation of virtual treatment delivery. Posttraumatic stress disorder (PTSD) Residential Rehabilitation Treatment Programs (P-RRTP) are a key mental health treatment for Veterans with PTSD who require more intensive interventions than outpatient care. During the pandemic, the W. G. (Bill) Hefner VA Healthcare System developed and implemented a Virtual Intensive Outpatient Program for PTSD (VIOPP) to meet the needs of the Veteran population. The purpose of this analysis was to compare the effectiveness of VIOPP to P-RRTP. METHOD: Analyses included N = 370 Veterans, n = 193 who completed P-RRTP between January 2018 to April 2020 and n = 177 who completed VIOPP between June 2020 and November 2022 and provided pre- and posttreatment scores. Pre- and posttreatment scores of the PTSD Checklist for DSM-5 (PCL-5) were available for all patients. Pre- and posttreatment depressive symptom scores from the Nine-item Patient Health Questionnaire (PHQ-9) were available for n = 254 Veterans. Paired and independent samples t tests evaluated differences in change scores overall and by treatment modality (residential vs. virtual). RESULTS: Results indicated a significant decrease in PCL-5 scores regardless of treatment modality, p < .001. Despite beginning VIOPP with significantly higher PCL-5 scores than P-RRTP, there were no significant differences in PCL-5 change scores between virtual (M = -16.94) and residential treatment (M = -17.10), p = .910. PHQ-9 scores also decreased significantly for both treatment groups. CONCLUSION: These analyses suggest that intensive virtual treatment has similar effectiveness to residential treatment for PTSD. This supports the development of intensive virtual interventions as viable alternatives to residential treatments and a valuable component within the continuum of PTSD care. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Considerations for the assessment of blast exposure in service members and veterans.

Introduction: Blast exposure is an increasingly present occupational hazard for military service members, particularly in modern warfare scenarios. The study of blast exposure in humans is limited by the lack of a consensus definition for blast exposure and considerable variability in measurement. Research has clearly demonstrated a robust and reliable effect of blast exposure on brain structure and function in the absence of other injury mechanisms. However, the exact mechanisms underlying these outcomes remain unclear. Despite clear contributions from preclinical studies, this knowledge has been slow to translate to clinical applications. The present manuscript empirically demonstrates the consequences of variability in measurement and definition across studies through a re-analysis of previously published data from the Chronic Effects of Neurotrauma Study 34. Methods: Definitions of blast exposure used in prior work were examined including Blast TBI, Primary Blast TBI, Pressure Severity, Distance, and Frequency of Exposure. Outcomes included both symptom report and cognitive testing. Results: Results demonstrate significant differences in outcomes based on the definition of blast exposure used. In some cases the same definition was strongly related to one type of outcome, but unrelated to another. Discussion: The implications of these results for the study of blast exposure are discussed and potential actions to address the major limitations in the field are recommended. These include the development of a consensus definition of blast exposure, further refinement of the assessment of blast exposure, continued work to identify relevant mechanisms leading to long-term negative outcomes in humans, and improved education efforts.

The national distribution of lymphatic filariasis cases in Malawi using patient mapping and geostatistical modelling.

BACKGROUND: In 2020 the World Health Organization (WHO) declared that Malawi had successfully eliminated lymphatic filariasis (LF) as a public health problem. Understanding clinical case distributions at a national and sub-national level is important, so essential care packages can be provided to individuals living with LF symptoms. This study aimed to develop a national database and map of LF clinical cases across Malawi using geostatistical modelling approaches, programme-identified clinical cases, antigenaemia prevalence and climate information. METHODOLOGY: LF clinical cases identified through programme house-to-house surveys across 90 sub-district administrative boundaries (Traditional Authority (TA)) and antigenaemia prevalence from 57 sampled villages in Malawi were used in a two-step geostatistical modelling process to predict LF clinical cases across all TAs of the country. First, we modelled antigenaemia prevalence in relation to climate covariates to predict nationwide antigenaemia prevalence. Second, we modelled clinical cases for unmapped TAs based on our antigenaemia prevalence spatial estimates. PRINCIPLE FINDINGS: The models estimated 20,938 (95% CrI 18,091 to 24,071) clinical cases in unmapped TAs (70.3%) in addition to the 8,856 (29.7%), programme-identified cases in mapped TAs. In total, the overall national number of LF clinical cases was estimated to be 29,794 (95% CrI 26,957 to 32,927). The antigenaemia prevalence and clinical case mapping and modelling found the highest burden of disease in Chikwawa and Nsanje districts in the Southern Region and Karonga district in the Northern Region of the country. CONCLUSIONS: The models presented in this study have facilitated the development of the first national LF clinical case database and map in Malawi, the first endemic country in sub-Saharan Africa. It highlights the value of using existing LF antigenaemia prevalence and clinical case data together with modelling approaches to produce estimates that may be used for the WHO dossier requirements, to help target limited resources and implement long-term health strategies.

Influence of affective instability on suicidal ideation beyond traumatic brain injury and posttraumatic stress disorder in veterans.

OBJECTIVE: Mild traumatic brain injury (TBI) is associated with long-term consequences, including greater risk for posttraumatic stress disorder (PTSD) and suicidal ideation. Affective instability is also independently related to PTSD and suicidality, which may explain why some individuals continue to experience chronic psychiatric complaints following mild TBI. The purpose of the present study was to evaluate affective instability as a key factor for PTSD and suicidal ideation among Veterans with and without TBI. METHOD: Participants (N = 299 Veterans; 86.96% male) completed the Personality Assessment Inventory (PAI) and structured clinical interviews for TBI and psychiatric diagnoses. Hierarchical linear regression was used to evaluate main and interaction effects. RESULTS: There were no significant differences in affective instability (p = 0.140) or suicidal ideation (p = 0.453) between Veterans with or without TBI. Individuals with TBI were more likely to have a PTSD diagnosis (p = 0.001). Analyses evaluating PTSD diagnosis as an outcome indicated a main effect of affective instability (p < 0.001), but not TBI (p = 0.619). Analyses evaluating suicidal ideation as an outcome demonstrated an interaction effect between PTSD and affective instability beyond the effects of TBI (p = 0.034). CONCLUSIONS: Severe Affective instability appears to be a key factor in suicidal ideation among Veterans beyond TBI or PTSD history. PTSD was more strongly associated with suicidality at lower and moderate levels of affective instability. At severe levels of affective instability, however, Veterans with and without PTSD experienced suicidal ideation at similar rates. Findings suggests that high levels of affective instability not better explained by other psychiatric conditions confers similar suicidality risk to that of PTSD in a Veteran population.

A blueprint for learning: How NHS England (London) learned during its response to the Covid-19 pandemic.

Identification and sharing of lessons is a key aspect of emergency preparedness, resilience and response (EPRR) activity in the national health service (NHS) in England (NHS England, 2022). The overall intent of the lessons identification and implementation process is to improve readiness and response to future major incidents and emergencies, such that, wherever possible, patient harm is minimised and staff well-being is maximised. In this commentary, we draw on international literature to outline some of the major challenges in healthcare organisations to learning from major incidents and emergencies. We describe our experience of identifying lessons and set out the approach used by NHS England (London) to identifying lessons from the NHS response to the Covid-19 pandemic in the capital. We describe the knowledge garnered in our organisation about learning methods during the Covid-19 pandemic. The commentary considers the different approaches to identifying lessons, and the subsequent challenges of learning and implementation. This paper places its focus on the learning processes followed rather than what was learned as a result. It also explores whether the learning process undertaken by NHS England (London) demonstrates the hallmarks of a learning organisation.

Elimination of lymphatic filariasis as a public health problem in Malawi.

BACKGROUND: Lymphatic filariasis (LF) is a parasitic disease transmitted by mosquitoes, causing severe pain, disfiguring, and disabling clinical conditions such as lymphoedema and hydrocoele. LF is a global public health problem affecting 72 countries, primarily in Africa and Asia. Since 2000, the World Health Organization (WHO) has led the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to support all endemic regions. This paper focuses on the achievements of the Malawi LF Elimination Programme between 2000 and 2020 to eliminate LF as a public health problem, making it the second sub-Saharan country to receive validation from the WHO. METHODOLOGY/PRINCIPAL FINDINGS: The Malawi LF Programme addressed the widespread prevalence of LF infection and disease across the country, using the recommended WHO GPELF strategies and operational research initiatives in collaboration with key national and international partners. First, to stop the spread of infection (i.e., interrupt transmission) and reduce the circulating filarial antigen prevalence from as high as 74.4% to below the critical threshold of 1-2% prevalence, mass drug administration (MDA) using a two-drug regime was implemented at high coverage rates (>65%) of the total population, with supplementary interventions from other programmes (e.g., malaria vector control). The decline in prevalence was monitored and confirmed over time using several impact assessment and post-treatment surveillance tools including the standard sentinel site, spot check, and transmission assessment surveys and alternative integrated, hotspot, and easy-access group surveys. Second, to alleviate suffering of the affected populations (i.e., control morbidity) the morbidity management and disability prevention (MMDP) package of care was implemented. Specifically, clinical case estimates were obtained via house-to-house patient searching activities; health personnel and patients were trained in self-care protocols for lymphoedema and/or referrals to hospitals for hydrocoele surgery; and the readiness and quality of treatment and services were assessed with new survey tools. CONCLUSIONS: Malawi's elimination of LF will ensure that future generations are not infected and suffer from the disfiguring and disabling disease. However, it will be critical that the Malawi LF Elimination programme remains vigilant, focussing on post-elimination surveillance and MMDP implementation and integration into routine health systems to support long-term sustainability and ongoing success. SUMMARY: Lymphatic filariasis, also known as elephantiasis, is a disabling, disfiguring, and painful disease caused by a parasite that infected mosquitoes transmit to millions of people worldwide. Since 2000, the Global Programme to Eliminate Lymphatic Filariasis (GPELF) has supported endemic countries such as Malawi in south-eastern Africa, to eliminate the disease as a public health problem. The Malawi National LF Elimination Programme has worked tirelessly over the past two decades to implement the GPELF recommended strategies to interrupt the transmission with a two-drug regime, and to alleviate suffering in patients with lymphoedema and/or hydrocoele through morbidity management and disability prevention. Additionally, the LF Programme has collaborated with national and international stakeholders to implement a range of supplementary operational research projects to address outstanding knowledge gaps and programmatic barriers. In 2020, the World Health Organisation validated that Malawi had successfully eliminated LF as a public health problem, making it the second country in sub-Saharan Africa to achieve this, which is remarkable given that Malawi previously had very high infection rates. The LF Programme now remains vigilant, putting its efforts towards post-elimination surveillance and the continued implementation of care for patients with chronic conditions. Malawi's elimination of LF will ensure that future generations are not affected by this devastating disease.

Phenotyping Depression After Mild Traumatic Brain Injury: Evaluating the Impact of Multiple Injury, Gender, and Injury Context.

The chronic mental health consequences of mild traumatic brain injury (TBI) are a leading cause of disability. This is surprising given the expectation of significant recovery after mild TBI, which suggests that other injury-related factors may contribute to long-term adverse outcomes. The objective of this study was to determine how number of prior injuries, gender, and environment/context of injury may contribute to depressive symptoms after mild TBI among deployed United States service members and veterans (SMVs). Data from the Long-term Impact of Military-Relevant Brain Injury Consortium Prospective Longitudinal Study was used to assess TBI injury characteristics and depression scores previously measured on the Patient Health Questionnaire-9 (PHQ-9) among a sample of 1456 deployed SMVs. Clinical diagnosis of mild TBI was defined via a multi-step process centered on a structured face-to-face interview. Logistical and linear regressions stratified by gender and environment of injury were used to model depressive symptoms controlling for sociodemographic and combat deployment covariates. Relative to controls with no history of mild TBI (n = 280), the odds ratios (OR) for moderate/severe depression (PHQ-9 ≥ 10) were higher for SMVs with one mild TBI (n = 358) OR: 1.62 (95% confidence interval [CI] 1.09-2.40, p = 0.016) and two or more mild TBIs (n = 818) OR: 1.84 (95% CI 1.31-2.59, p < 0.001). Risk differences across groups were assessed in stratified linear models, which found that depression symptoms were elevated in those with a history of multiple mild TBIs compared with those who had a single mild TBI (p < 0.001). Combat deployment-related injuries were also associated with higher depression scores than injuries occurring in non-combat or civilian settings (p < 0.001). Increased rates of depression after mild TBI persisted in the absence of post-traumatic stress disorder. Both men and women SMVs separately exhibited significantly increased depressive symptom scores if they had had combat-related mild TBI. These results suggest that contextual information, gender, and prior injury history may influence long-term mental health outcomes among SMVs with mild TBI exposure.

Subcortical functional connectivity and its association with walking performance following deployment related mild TBI.

Introduction: The relation between traumatic brain injury (TBI), its acute and chronic symptoms, and the potential for remote neurodegenerative disease is a priority for military research. Structural and functional connectivity (FC) of the basal ganglia, involved in motor tasks such as walking, are altered in some samples of Service Members and Veterans with TBI, but any behavioral implications are unclear and could further depend on the context in which the TBI occurred. Methods: In this study, FC from caudate and pallidum seeds was measured in Service Members and Veterans with a history of mild TBI that occurred during combat deployment, Service Members and Veterans whose mild TBI occurred outside of deployment, and Service Members and Veterans who had no lifetime history of TBI. Results: FC patterns differed for the two contextual types of mild TBI. Service Members and Veterans with deployment-related mild TBI demonstrated increased FC between the right caudate and lateral occipital regions relative to both the non-deployment mild TBI and TBI-negative groups. When evaluating the association between FC from the caudate and gait, the non-deployment mild TBI group showed a significant positive relationship between walking time and FC with the frontal pole, implicated in navigational planning, whereas the deployment-related mild TBI group trended towards a greater negative association between walking time and FC within the occipital lobes, associated with visuo-spatial processing during navigation. Discussion: These findings have implications for elucidating subtle motor disruption in Service Members and Veterans with deployment-related mild TBI. Possible implications for future walking performance are discussed.

Subjective cognitive complaints and objective cognitive functioning in combat veterans: Effects of PTSD and deployment mild TBI.

OBJECTIVES: (1) Examine the relationship between subjective cognitive complaints and objective cognitive functioning in combat veterans; and (2) evaluate conditional effects of posttraumatic stress disorder (PTSD) and deployment-related mild traumatic brain injury (TBI) within that relationship. METHOD: Combat veterans (N = 225, 86.22% male) completed a lifetime TBI interview, a structured interview assessing PTSD symptoms, a neuropsychological assessment battery, and a self-report measure of cognitive symptoms. RESULTS: All correlations between subjective cognitive complaints and objective cognitive measures were not statistically significant. Hierarchical linear regression indicated that cognitive performance was not significantly related to cognitive complaints, but both PTSD diagnosis and history of deployment mild TBI explained a significant amount of unique variance in self-reported cognitive symptoms. Interactions between the studied variables were not significant. CONCLUSIONS: PTSD and history of deployment mild TBI were uniquely related to cognitive complaints, but cognitive test performance was not. No confounding effects of PTSD or deployment mild TBI were observed in the relationship between cognitive performance and cognitive complaints. This provides support that symptom distress may be a better explanatory factor for perception of lower cognitive functioning than actual cognitive performance.

Relation of Aerobic Activity to Cognition and Well-being in Chronic Mild Traumatic Brain Injury: A LIMBIC-CENC Study.

INTRODUCTION: Because chronic difficulties with cognition and well-being are common after mild traumatic brain injury (mTBI) and aerobic physical activity and exercise (PAE) is a potential treatment and mitigation strategy, we sought to determine their relationship in a large sample with remote mTBI. MATERIALS AND METHODS: The Long-Term Impact of Military-Relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium prospective longitudinal study is a national multicenter observational study of combat-exposed service members and veterans. Study participants with positive mTBI histories (n = 1,087) were classified as "inactive" (23%), "insufficiently active" (46%), "active" (19%), or "highly active" (13%) based on the aerobic PAE level. The design was a cross-sectional analysis with multivariable regression. PAE was reported on the Behavioral Risk Factor Surveillance System. Preselected primary outcomes were seven well-validated cognitive performance tests of executive function, learning, and memory: The California Verbal Learning Test-Second Edition Long-Delay Free Recall and Total Recall, Brief Visuospatial Memory Test-Revised Total Recall, Trail-Making Test-Part B, and NIH Toolbox for the Assessment of Neurological Behavior and Function Cognition Battery Picture Sequence Memory, Flanker, and Dimensional Change Card Sort tests. Preselected secondary outcomes were standardized self-report questionnaires of cognitive functioning, life satisfaction, and well-being. RESULTS: Across the aerobic activity groups, cognitive performance tests were not significantly different. Life satisfaction and overall health status scores were higher for those engaging in regular aerobic activity. Exploratory analyses also showed better working memory and verbal fluency with higher aerobic activity levels. CONCLUSIONS: An association between the aerobic activity level and the preselected primary cognitive performance outcome was not demonstrated using this study sample and methods. However, higher aerobic activity levels were associated with better subjective well-being. This supports a clinical recommendation for regular aerobic exercise among persons with chronic or remote mTBI. Future longitudinal analyses of the exercise-cognition relationship in chronic mTBI populations are recommended.

Time doesn't heal all: PTSD symptoms exacerbate the relationship between age and pain intensity.

Objective: Posttraumatic stress disorder (PTSD) symptoms and pain interfere with daily functioning and quality of life for many combat Veterans. As individuals age, pain symptoms tend to increase whereas PTSD symptoms tend to decrease. PTSD symptoms exacerbate pain, but the nature of this relationship across the aging process is unclear. The purpose of this study was to determine how PTSD symptoms affect the association between age and pain intensity. Methods: Participants in this cross-sectional study included 450 Veterans (80% male) who served after September 11, 2001. PTSD and pain intensity ratings were assessed by the PTSD Checklist for DSM-5 (PCL-5) and the Brief Pain Inventory (BPI), respectively. Hierarchical multiple linear regression evaluated main and interaction effects between age, PTSD symptoms, and pain intensity. Results: Age (B = 0.04, p < 0.001) and PTSD symptoms (B = 0.05, p < 0.001) were positively associated with pain intensity. Age and PTSD symptoms were inversely correlated (r = -0.16, p < 0.001). PTSD symptoms exacerbated the relationship between age and pain intensity (ΔR2 = 0.01, p = 0.036). Specifically, when greater PTSD symptoms were reported at older ages, pain intensity was significantly higher. Conclusion: Results of these analyses suggests that age is important when considering the effects of PTSD symptoms on pain intensity ratings. Specifically, pain intensity ratings are higher in older Veterans with PTSD symptoms. These findings underscore the importance for clinical providers to evaluate trauma history and PTSD symptoms in older Veterans reporting pain symptoms.

Symptom validity indices in the Posttraumatic Stress Disorder Checklist for DSM-5.

The use of symptom validity tests (SVTs) is standard practice in psychodiagnostic assessments. Embedded measures are indices within self-report measures. To date, no embedded SVTs have been identified in the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5). This research aimed to develop and validate PCL-5 SVTs in two samples of veterans. Participants completed one of two prospective research studies that included cognitive and psychological tests. Participants in Study 1 were veterans (N = 464) who served following the September 11, 2001, terrorist attacks; participants in Study 2 were veterans or service members (N = 338) who had been deployed to Iraq and/or Afghanistan. Both studies included the PCL-5 and the Structured Inventory of Malingered Symptomatology (SIMS), the latter of which served as the criterion for identifying PCL-5 SVTs. For Study 1, two separate SVTs were developed: the PCL-5 Symptom Severity scale (PSS), based on the PCL-5 total score, and the PCL-5 Rare Items scale (PRI), based on PCL-5 items infrequently endorsed at the highest item ratings. At the most conservative SIMS cutoff score, the PSS achieved excellent discrimination for both the Study 1, AUC = .840, and Study 2 samples, AUC = .858, with specific cutoff scores of ≥ 51 and ≥ 56 maximizing sensitivity while maintaining a specificity of .90. The PRI achieved good discrimination, AUCs = .760 and.726, respectively, with a cutoff score of 2 or higher indicated by both studies. The results of these two studies provide provisional support for these two embedded SVTs in the PCL-5.

Distress tolerance mitigates effects of posttraumatic stress, traumatic brain injury, and blast exposure on psychiatric and health outcomes.

BACKGROUND: Exposure to blasts is common among service members and history of these exposures has been associated with chronic psychiatric and health outcomes. Evidence suggests that distress tolerance (DT) may moderate this relationship and be a valuable treatment target in this population. The purpose of this manuscript was to evaluate DT as a modifying factor in the association between posttraumatic stress disorder (PTSD), mild traumatic brain injury (TBI), blast exposure, and functional indicators. METHOD: Participants were 275 (86.55% male) combat veterans who served in Iraq or Afghanistan after September 11, 2001. Clinical interviews for PTSD diagnosis, TBI history, and blast exposure were administered, and participants completed self-report questionnaires (DT, PTSD symptom severity, depressive symptom severity, neurobehavioral symptom severity, sleep quality, pain interference, and quality of life). RESULTS: DT was significantly associated with all functional indicators beyond PTSD diagnosis, mild TBI, and blast severity. There were significant interaction effects between DT and PTSD diagnosis for posttraumatic stress symptom severity, sleep quality, and quality of life. Specifically, there were significant differences in these reported functional indicators between individuals with and without a PTSD diagnosis as DT increases, such that reported symptoms were lower (quality of life better) for individuals without PTSD as DT improved. CONCLUSION: Our results demonstrate that DT might be a key factor in postdeployment function for military service members. Treatments targeting DT may be particularly effective in individuals who attribute psychiatric symptoms to history of blast exposure. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Validation of Military Occupational Specialty as a Proxy for Blast Exposure Using the Salisbury Blast Interview.

Abstract Evaluating large data sets precludes the ability to directly measure individual experiences, instead relying on proxies to infer certain constructs. Blast exposure is a construct of study currently in its infancy, resulting in diverse definitions and measurements across studies. The purpose of the present study was to validate military occupational specialty (MOS) as a proxy for blast exposure in combat veterans. A total of 256 veterans (86.33% male) completed the Salisbury Blast Interview (SBI) and Mid-Atlantic Mental Illness Research Education and Clinical Center (MIRECC) Assessment of Traumatic Brain Injury (MMA-TBI). MOS was collected through record review and categorized into low and high risk for blast exposure. Chi-square analyses and t tests compared SBI metrics between MOS categories. Receiver operating characteristic (ROC) analyses evaluated the diagnostic accuracy of MOS category in determining blast exposure severity. Veterans in high-risk MOS were more likely to have experienced blast and deployment TBI (ps < 0.001) than were those in low-risk MOS. ROC analyses indicated good specificity (81.29-88.00) for blast and deployment TBI outcomes, suggesting that low-risk MOS is generally associated with an absence of blast and deployment TBI outcomes. Sensitivity was low (36.46-51.14), indicating that MOS risk level was not a good predictor of the presence of these outcomes. Results demonstrate that high-risk MOSs will identify individuals with blast exposure and deployment TBI history whereas low-risk MOSs will capture a highly variable group. Accuracy of MOS categorization was not acceptable for diagnostic-level tests; however, results support its use as a screening measure for a history of exposure to blast, use in epidemiological studies, and considerations for military policy.

Putting the pieces together to understand anger in combat veterans and service members: Psychological and physical contributors.

Dysregulated anger can result in devastating health and interpersonal consequences for individuals, families, and communities. Compared to civilians, combat veterans and service members (C-V/SM) report higher levels of anger and often have risk factors for anger including posttraumatic stress disorder (PTSD), traumatic brain injury (TBI), pain, alcohol use, and impaired sleep. The current study examined the relative contributions of established variables associated with anger (e.g., combat exposure, current PTSD symptoms, history of TBI, pain interference, and hazardous alcohol use) in 1263 C-V/SM. Sleep impairments, represented by poor sleep quality and obstructive sleep apnea (OSA) risk, were also evaluated as potential mediators of the relationships between established risk factors and anger, and therefore potential modifiable treatment targets. Multiple regression model results revealed that PTSD symptoms (ß = 0.517, p < .001), OSA risk (ß = 0.057, p = .016), pain interference (ß = 0.214, p < .001), and hazardous alcohol use (ß = 0.054, p = .009) were significantly associated with anger. Results of the mediation models revealed that OSA risk accounted for the association between PTSD and anger, in addition to the association between pain interference and anger. The current study extends previous literature by simultaneously examining factors associated with anger using a multivariable model in a large sample of C-V/SM. Additionally, treating OSA may be a novel way to reduce anger in C-V/SM who have PTSD and/or pain interference.