A methodology for assessing deployment trauma and its consequences in OEF/OIF/OND veterans: The TRACTS longitudinal prospective cohort study

Examination of Congruity between Subjective and Objective Working Memory in Veterans with Mild TBI and Relation to Psychiatric Symptoms and Childhood Trauma

OBJECTIVES

There is conflicting evidence regarding congruence between subjective cognitive decline and objective cognitive performance for individuals with a history of mild traumatic brain injury (mTBI). The current study investigated the congruity between subjective and objective cognition, particularly working memory, among veterans with an mTBI history, accounting for post-traumatic stress disorder (PTSD) and childhood trauma.

METHODS

Participants included 35 veterans with a history of mTBI sustained during deployment. Participants completed measures of subjective [i.e., Behavioral Inventory Rating of Executive Functioning (BRIEF)] and objective working memory (i.e., WAIS-IV working memory index). Congruity between subjective and objective working memory was examined using linear regression. Bonferroni-corrected correlations were run to explore relationships among working memory, psychiatric symptoms, mTBI severity, and childhood trauma.

RESULTS

Among Veterans with mTBI, subjective working memory and objective working memory performance were not significantly related (p > 0.05); however, the overall model was significant (p < 0.0001), and childhood trauma was a notable predictor (p = 0.02). Greater PTSD, depression, and sleep symptoms were significantly related to increased subjective working memory concerns, even after Bonferroni adjustments (ps < 0.0001). Better objective working memory was significantly related to a fewer number of childhood traumatic events; however, this did not sustain corrections. The majority of individuals (67%) endorsed significant working memory complaints, despite objectively performing within normal limits (within 1 SD and above).

CONCLUSIONS

Subjective-objective working memory congruity among veterans with mTBI was limited. Subjective, but not objective, working memory concerns were associated with greater PTSD, depression, and sleep symptoms. Childhood trauma was a notable factor that contributed to both subjective and objective cognitive concerns. There remains clinical value in assessing subjective cognitive concerns given the strong relationships with psychiatric problems and, hence, a focus for intervention.

Metabolic syndrome is associated with reduced default mode network functional connectivity in young post-9/11 Veterans

Metabolic syndrome is a collection of health factors that increases risk for cardiovascular disease. A condition of aging, metabolic syndrome is associated with reduced brain network integrity, including functional connectivity alterations among the default mode, regions vulnerable to neurodegeneration. Prevalence of metabolic syndrome is elevated in younger populations including post-9/11 Veterans and individuals with posttraumatic stress disorder, but it is unclear whether metabolic syndrome affects brain function in earlier adulthood. Identifying early effects of metabolic syndrome on brain network integrity is critical, as these impacts could contribute to increased risk for cognitive disorders later in life for Veterans. The current study examined whether metabolic syndrome and its individual components were associated with default mode functional connectivity. We also explored the contribution of posttraumatic stress disorder and traumatic brain injury on these metabolic syndrome-brain relationships. Post-9/11 Veterans with combat deployment history (95 with and 325 without metabolic syndrome) underwent functional magnetic resonance imaging to capture seed-based resting-state functional connectivity within the default mode. The metabolic syndrome group demonstrated reduced positive functional connectivity between the posterior cingulate cortex seed and the bilateral superior frontal gyrus. Data-driven analyses demonstrated that metabolic syndrome components, particularly cholesterol and central adiposity, were associated with widespread reductions in default mode network connectivity. Functional connectivity was also reduced in participants with metabolic syndrome but without current posttraumatic stress disorder diagnosis and with traumatic brain injury history. These results suggest that metabolic syndrome disrupts resting-state functional connectivity decades earlier than prior work has shown.

Posttraumatic survivor guilt is associated with white matter microstructure alterations

BACKGROUND

Military veterans with posttraumatic stress disorder (PTSD) commonly experience posttraumatic guilt. Guilt over commission or omission evolves when responsibility is assumed for an unfortunate outcome (e.g., the death of a fellow combatant). Survivor guilt is a state of intense emotional distress experienced by the weight of knowing that one survived while others did not.

METHODS

This study of the Translational Research Center for TBI and Stress Disorders (TRACTS) analyzed structural and diffusion-weighted magnetic resonance imaging data from 132 male Iraq/Afghanistan veterans with PTSD. The Clinician-Administered PTSD Scale for DSM-IV (CAPS-IV) was employed to classify guilt. Thirty (22.7 %) veterans experienced guilt over acts of commission or omission, 34 (25.8 %) experienced survivor guilt, and 68 (51.5 %) had no posttraumatic guilt. White matter microstructure (fractional anisotropy, FA), cortical thickness, and cortical volume were compared between veterans with guilt over acts of commission or omission, veterans with survivor guilt, and veterans without guilt.

RESULTS

Veterans with survivor guilt had significantly lower white matter FA compared to veterans who did not experience guilt (p < .001), affecting several regions of major white matter fiber bundles. There were no significant differences in white matter FA, cortical thickness, or volumes between veterans with guilt over acts of commission or omission and veterans without guilt (p > .050).

LIMITATIONS

This cross-sectional study with exclusively male veterans precludes inferences of causality between the studied variables and generalizability to the larger veteran population that includes women.

CONCLUSION

Survivor guilt may be a particularly impactful form of posttraumatic guilt that requires specific treatment efforts targeting brain health.

Examining the Utility of Veterans Health Administration (VHA) Traumatic Brain Injury Screening among Women Veterans: Recommendations for Expansion to Include Interpersonal Violence

Women veterans (WVs) are more likely than men veterans to experience traumatic brain injury (TBI) from causes unrelated to deployment. Yet, current Veterans Health Administration (VHA) TBI screening focuses on deployment. This study examines the utility of the VHA TBI screening tool for WVs. Using the Boston Assessment for TBI-Lifetime (BAT-L) as the gold standard, sensitivity and specificity of the VHA screen were identified for deployment and non-deployment injuries. Injuries missed by the screen were thematically described. Sensitivity and specificity were compared by context (research, clinical). Ninety WVs were included; fifty-three (60.9%) met TBI criteria per the BAT-L. For TBIs occurring during deployment, sensitivity was higher in research (89.1%) compared to clinics (61.7%); specificity was lower in research (60.7%) compared to clinics (93.0%). The BAT-L identified 27 non-deployment TBIs not captured by the VHA screen, most frequently from physical assault or sports. The VHA screen does not include non-deployment events; thus, non-deployment sensitivity and specificity could not be calculated. For lifetime TBIs (deployment + non-deployment etiologies), sensitivity was higher in research (73.5%) compared to clinics (48.9%). Specificity was lower in research (60.0%) compared to clinics (100.0%). Findings can inform improvements to TBI screening among WVs, including expansion for interpersonal violence.

Poor sleep and decreased cortical thickness in veterans with mild traumatic brain injury and post-traumatic stress disorder

BACKGROUND

Poor sleep quality has been associated with changes in brain volume among veterans, particularly those who have experienced mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD). This study sought to investigate (1) whether poor sleep quality is associated with decreased cortical thickness in Iraq and Afghanistan war veterans, and (2) whether these associations differ topographically depending on the presence or absence of mTBI and PTSD.

METHODS

A sample of 440 post-9/11 era U.S. veterans enrolled in the Translational Research Center for Traumatic Brain Injury and Stress Disorders study at VA Boston, MA from 2010 to 2022 was included in the study. We examined the relationship between sleep quality, as measured by the Pittsburgh Sleep Quality Index (PSQI), and cortical thickness in veterans with mTBI (n = 57), PTSD (n = 110), comorbid mTBI and PTSD (n = 129), and neither PTSD nor mTBI (n = 144). To determine the topographical relationship between subjective sleep quality and cortical thickness in each diagnostic group, we employed a General Linear Model (GLM) at each vertex on the cortical mantle. The extent of topographical overlap between the resulting statistical maps was assessed using Dice coefficients.

RESULTS

There were no significant associations between PSQI and cortical thickness in the group without PTSD or mTBI (n = 144) or in the PTSD-only group (n = 110). In the mTBI-only group (n = 57), lower sleep quality was significantly associated with reduced thickness bilaterally in frontal, cingulate, and precuneus regions, as well as in the right parietal and temporal regions (β = -0.0137, P < 0.0005). In the comorbid mTBI and PTSD group (n = 129), significant associations were observed bilaterally in frontal, precentral, and precuneus regions, in the left cingulate and the right parietal regions (β = -0.0094, P < 0.0005). Interaction analysis revealed that there was a stronger relationship between poor sleep quality and decreased cortical thickness in individuals with mTBI (n = 186) compared to those without mTBI (n = 254) specifically in the frontal and cingulate regions (β = -0.0077, P < 0.0005).

CONCLUSIONS

This study demonstrates a significant relationship between poor sleep quality and lower cortical thickness primarily within frontal regions among individuals with both isolated mTBI or comorbid diagnoses of mTBI and PTSD. Thus, if directionality is established in longitudinal and interventional studies, it may be crucial to consider addressing sleep in the treatment of veterans who have sustained mTBI.

Association between metabolic syndrome and white matter integrity in young and mid-age post-9/11 adult Veterans

Metabolic syndrome has been associated with reduced brain white matter integrity in older individuals. However, less is known about how metabolic syndrome might impact white matter integrity in younger populations. This study examined metabolic syndrome-related global and regional white matter integrity differences in a sample of 537 post-9/11 Veterans. Metabolic syndrome was defined as ≥3 factors of: increased waist circumference, hypertriglyceridemia, low high-density lipoprotein cholesterol, hypertension, and high fasting glucose. T1 and diffusion weighted 3 T MRI scans were processed using the FreeSurfer image analysis suite and FSL Diffusion Toolbox. Atlas-based regions of interest were determined from a combination of the Johns Hopkins University atlas and a Tract-Based Spatial Statistics-based FreeSurfer WMPARC white matter skeleton atlas. Analyses revealed individuals with metabolic syndrome (n = 132) had significantly lower global fractional anisotropy than those without metabolic syndrome (n = 405), and lower high-density lipoprotein cholesterol levels was the only metabolic syndrome factor significantly related to lower global fractional anisotropy levels. Lobe-specific analyses revealed individuals with metabolic syndrome had decreased fractional anisotropy in frontal white matter regions compared with those without metabolic syndrome. These findings indicate metabolic syndrome is prevalent in this sample of younger Veterans and is related to reduced frontal white matter integrity. Early intervention for metabolic syndrome may help alleviate adverse metabolic syndrome-related brain and cognitive effects with age.

Secondary RBD: Not just neurodegeneration

Rapid eye movement sleep behavior disorder is a parasomnia characterized by excessive muscle activity during rapid eye movement sleep (rapid eye movement sleep without atonia), along with dream enactment behavior. Isolated rapid eye movement sleep behavior disorder tends to occur in older males and is of concern due to the known link to Parkinson's disease and other synucleinopathies. When rapid eye movement sleep behavior disorder occurs in association with other neurological or general medical conditions, or resulting from the use of various substances, it is called secondary rapid eye movement sleep behavior disorder; the most common cause is neurodegenerative illness, specifically the synucleinopathies. Here, the focus will be on the subset of secondary rapid eye movement sleep behavior disorder in which there is no neurodegenerative disease.

Sociodemographic and Health Characteristics of Hispanic Veteran Patients With Traumatic Brain Injury and Its Association to Mortality: A Pilot Study

INTRODUCTION

Traumatic brain injury (TBI) is among the most common conditions in the military. VA Caribbean Healthcare System (VACHS) patients with Traumatic Brain Injury (TBI) have a higher mortality rate than Veterans in other VA health care systems in the United States. The main goal of this study was to develop sociodemographic profiles and outline health characteristics of Hispanic patients with TBI treated at the VA Caribbean Healthcare System in a search for potential explanations to account for the higher mortality rate. This study advocates for equity in health services provided for minorities inside the militia.

MATERIALS AND METHODS

Data collected from electronic medical records and VA databases were used to create sociodemographic and health characteristics profiles, in addition to survival models. The population of the study were post 911 Veteran soldiers who had been diagnosed with TBI. Adjusted models were created to provide hazard ratios (HR) for mortality risk.

RESULTS

Out of the 16,549 files available from all 10 selected VA sites, 526 individuals were identified as treated at the VACHS. Of 526 subjects screened, 39 complied with the inclusion/exclusion criteria. Results include: 94.4% male, 48.7% between the ages of 21 and 41 years, 89.7% have depression, 66.7% have post-traumatic stress disorder (PTSD), 82.1% receive occupational therapy, 94.9% have severe headaches, 100% suffer from pain, 94.9% have memory problems, and 10.3% have had suicidal thoughts. Over 60% had a first-hand explosion experience, be it just the explosion or with another type of injury. Data showed that 33% of our patients had a Magnetic Resonance Imaging (MRI), 31% had a CT, 15.4% had a SPECT, and 2.6% had PET scan. Significant associations were found between MRIs and speech therapies, and MRIs and total comorbidities. The Cox proportional-hazards model for survival adjusted for age, gender, race/ethnicity, and comorbidities shows that VACHS Veterans diagnosed with a TBI had a higher mortality risk rate (HR 1.23 [95% CI 1.10, 1.37]) when compared to the other 9 health centers with the highest percentage of Hispanic Veterans.

CONCLUSIONS

Since explosions were the most common mechanism of injury, further research is needed into the experiences of Veterans in connection with this specific variable. A high percentage of the patients suffered from depression and PTSD. Additionally, over half of the patients had an unmeasured TBI severity. The effects these aspects have on symptomatology and how they hinder the recovery process in Hispanic patients should be examined in further detail. It is also important to highlight that family and friends' support could be key for injury treatment. This study highlights the use of the 4 types of scans (MRI, CT, PET/CT, and SPECT/CT) as ideal diagnosis tools. The alarming number of patients with suicidal thoughts should be a focus in upcoming studies. Future studies should aim to determine whether increased death rates in TBI Veterans can be linked to other United States islander territories. Concepts, such as language barriers, equal resource allocation, and the experiences of Veterans with TBIs should be further explored in this Veteran population.

Traumatic Brain Injury and Posttraumatic Stress Disorder Are Associated with Physical Health Burden among Post-9/11 Women Veterans

Background: Little research focuses on physical health outcomes of traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) among post-9/11 women veterans (WVs). This study examined lifetime TBI, current PTSD, and their associations with biomarkers of cardiometabolic health, sleep, pain, and functional disability among post-9/11 WVs. Methods: WVs (n = 90) from the Translational Research Center for TBI and Stress Disorders longitudinal cohort study were included in this study. Gold standard clinician administered interviews assessed lifetime TBI (Boston Assessment of TBI-Lifetime) and current PTSD symptoms (Clinician-Administered PTSD Scale-IV). Objective measures of health included waist-hip ratio (WHR) and fasted blood biomarker (high density lipoprotein [HDL], low density lipoprotein [LDL], blood glucose, triglycerides) levels. Self-reported surveys assessed sleep, pain, and functional disability. Results: Just under two-thirds (58.9%) of WVs experienced a lifetime TBI, and just over half (53.3%) of this sample had a current PTSD diagnosis at the time of testing. Lifetime TBI was significantly associated with higher WHR, triglycerides levels, and worse pain and sleep (ps = <0.01 to 0.02; ds = 0.01 to 1.12). Current PTSD was significantly associated with higher WHR, lower HDL, and worse pain and sleep (ps = <0.01 to 0.02; ds = 0.009 to 1.19). PTSD was significantly associated with lower total functioning and each of its subdomains (βs = -0.58 to 0.63; ps = <0.001 to 0.02). Lifetime TBI was significantly associated with total functioning, mobility, and life/work (βs = -0.20 to 0.30; ps = <0.01 to 0.02). Conclusions: These findings highlight the importance of screening for lifetime TBI and cardiovascular disease for WVs and support transdiagnostic treatment approaches targeting physical health outcomes.

STEP-Home transdiagnostic group reintegration workshop to improve mental health outcomes for post-9/11 Veterans: Design, methods, and rationale for a randomized controlled behavioral trial

BACKGROUND

Many post-9/11 U.S. combat Veterans experience difficulty readjusting to civilian life after military service, including relationship problems, reduced work productivity, substance misuse, and increased anger control problems. Mental health problems are frequently cited as causing these difficulties, driven by unparalleled rates of mild traumatic brain injury, posttraumatic stress, and other co-occurring emotional and physical conditions. Given the high prevalence of multimorbidity in this cohort, acceptable, non-stigmatizing, transdiagnostic interventions targeting reintegration are needed. The STEP-Home reintegration workshop has the potential to significantly improve skills to foster civilian reintegration, increase engagement in VA services, and improve mental health outcomes in Veterans with and without diagnosed clinical conditions.

METHODS/DESIGN

Ongoing from 2019, a prospective, two-site, randomized trial of 206 post-9/11 U.S. military Veterans randomized to receive either 12 sessions of the STEP-Home transdiagnostic reintegration workshop (SH; Active Intervention) or Present Centered Reintegration Group Therapy (PCRGT; Active Control Intervention). Primary outcomes are reintegration, anger, and emotional regulation post-intervention and at 3-months post-intervention. Secondary outcomes include measures of mental health, functional and vocational status, and cognition.

CONCLUSION

This study addresses an important gap in transdiagnostic interventions to improve civilian reintegration in post-9/11 Veterans. STEP-Home is designed to promote treatment engagement and retention, opening the door to critically needed VA care, and ultimately reducing long-term healthcare burden of untreated mental health illness in U.S. Veterans.

TRIAL REGISTRATION

Clinicaltrials.gov: D2907-R.

Intimate partner violence perpetration among veterans: associations with neuropsychiatric symptoms and limbic microstructure

Background

Intimate partner violence (IPV) perpetration is highly prevalent among veterans. Suggested risk factors of IPV perpetration include combat exposure, post-traumatic stress disorder (PTSD), depression, alcohol use, and mild traumatic brain injury (mTBI). While the underlying brain pathophysiological characteristics associated with IPV perpetration remain largely unknown, previous studies have linked aggression and violence to alterations of the limbic system. Here, we investigate whether IPV perpetration is associated with limbic microstructural abnormalities in military veterans. Further, we test the effect of potential risk factors (i.e., PTSD, depression, substance use disorder, mTBI, and war zone-related stress) on the prevalence of IPV perpetration.

Methods

Structural and diffusion-weighted magnetic resonance imaging (dMRI) data were acquired from 49 male veterans of the Iraq and Afghanistan wars (Operation Enduring Freedom/Operation Iraqi Freedom; OEF/OIF) of the Translational Research Center for TBI and Stress Disorders (TRACTS) study. IPV perpetration was assessed using the psychological aggression and physical assault sub-scales of the Revised Conflict Tactics Scales (CTS2). Odds ratios were calculated to assess the likelihood of IPV perpetration in veterans with either of the following diagnoses: PTSD, depression, substance use disorder, or mTBI. Fractional anisotropy tissue (FA) measures were calculated for limbic gray matter structures (amygdala-hippocampus complex, cingulate, parahippocampal gyrus, entorhinal cortex). Partial correlations were calculated between IPV perpetration, neuropsychiatric symptoms, and FA.

Results

Veterans with a diagnosis of PTSD, depression, substance use disorder, or mTBI had higher odds of perpetrating IPV. Greater war zone-related stress, and symptom severity of PTSD, depression, and mTBI were significantly associated with IPV perpetration. CTS2 (psychological aggression), a measure of IPV perpetration, was associated with higher FA in the right amygdala-hippocampus complex (r = 0.400, p = 0.005).

Conclusion

Veterans with psychiatric disorders and/or mTBI exhibit higher odds of engaging in IPV perpetration. Further, the more severe the symptoms of PTSD, depression, or TBI, and the greater the war zone-related stress, the greater the frequency of IPV perpetration. Moreover, we report a significant association between psychological aggression against an intimate partner and microstructural alterations in the right amygdala-hippocampus complex. These findings suggest the possibility of a structural brain correlate underlying IPV perpetration that requires further research.

Importance of validity testing in psychiatric assessment: evidence from a sample of multimorbid post-9/11 veterans

OBJECTIVE

Performance validity (PVTs) and symptom validity tests (SVTs) are necessary components of neuropsychological testing to identify suboptimal performances and response bias that may impact diagnosis and treatment. The current study examined the clinical and functional characteristics of veterans who failed PVTs and the relationship between PVT and SVT failures.

METHOD

Five hundred and sixteen post-9/11 veterans participated in clinical interviews, neuropsychological testing, and several validity measures.

RESULTS

Veterans who failed 2+ PVTs performed significantly worse than veterans who failed one PVT in verbal memory (Cohen's d = .60-.69), processing speed (Cohen's d = .68), working memory (Cohen's d = .98), and visual memory (Cohen's d = .88-1.10). Individuals with 2+ PVT failures had greater posttraumatic stress (PTS; β = 0.16; p = .0002), and worse self-reported depression (β = 0.17; p = .0001), anxiety (β = 0.15; p = .0007), sleep (β = 0.10; p = .0233), and functional outcomes (β = 0.15; p = .0009) compared to veterans who passed PVTs. 7.8% veterans failed the SVT (Validity-10; ≥19 cutoff); Multiple PVT failures were significantly associated with Validity-10 failure at the ≥19 and ≥23 cutoffs (p's < .0012). The Validity-10 had moderate correspondence in predicting 2+ PVTs failures (AUC = 0.83; 95% CI = 0.76, 0.91).

CONCLUSION

PVT failures are associated with psychiatric factors, but not traumatic brain injury (TBI). PVT failures predict SVT failure and vice versa. Standard care should include SVTs and PVTs in all clinical assessments, not just neuropsychological assessments, particularly in clinically complex populations.

Rates and Predictors of Rapid Eye Movement Sleep Behavior Disorder Symptoms Among Post-9/11 Veterans

OBJECTIVE

Posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI), which are prevalent conditions among post-9/11 veterans, increase risks of rapid eye movement (REM) sleep behavior disorder (RBD) and degenerative synucleinopathy. Rates and predictors of RBD symptoms were investigated by screening post-9/11 veterans for RBD with a validated questionnaire.

METHODS

In this cross-sectional analysis, consecutive patients in the Houston Translational Research Center for TBI and Stress Disorders (TRACTS) were screened with the English translation of the RBD Questionnaire-Hong Kong (RBDQ-HK). In addition to data from the standard TRACTS battery, systematic chart review was used to identify known sleep disorders mimicking or manifesting RBD.

RESULTS

Of the 119 patients with available RBDQ-HK scores, 71 (60%) and 65 (55%) screened positive for RBD, when a total score ≥21 and a factor 2 score ≥8 were used as cutoff scores, respectively. Univariable analyses with both cutoffs showed consistent associations between a positive RBDQ-HK screen and global sleep quality, number of TBI exposures, and PTSD severity. Multivariable logistic regression with total score ≥21 as a cutoff indicated that PTSD severity (odds ratio=1.06, 95% CI=1.02-1.10) and number of TBIs (odds ratio=1.63, 95% CI=1.16-2.41) were independent predictors of a positive screen, whereas global sleep quality was no longer significant. Multivariable logistic regression with factor 2 score ≥8 as a cutoff showed similar results.

CONCLUSIONS

Interdisciplinary parasomnia assessment, further validation of RBD screens, and standardized reporting of REM sleep without atonia could provide necessary information on the pathophysiological relationships linking PTSD, TBI, RBD symptoms, and ultimately synucleinopathy risk among post-9/11 veterans.

Twenty Years of Blast-Induced Neurotrauma: Current State of Knowledge

Blast-induced neurotrauma (BINT) is an important injury paradigm of neurotrauma research. This short communication summarizes the current knowledge of BINT. We divide the BINT research into several broad categories-blast wave generation in laboratory, biomechanics, pathology, behavioral outcomes, repetitive blast in animal models, and clinical and neuroimaging investigations in humans. Publications from 2000 to 2023 in each subdomain were considered. The analysis of the literature has brought out salient aspects. Primary blast waves can be simulated reasonably in a laboratory using carefully designed shock tubes. Various biomechanics-based theories of BINT have been proposed; each of these theories may contribute to BINT by generating a unique biomechanical signature. The injury thresholds for BINT are in the nascent stages. Thresholds for rodents are reasonably established, but such thresholds (guided by primary blast data) are unavailable in humans. Single blast exposure animal studies suggest dose-dependent neuronal pathologies predominantly initiated by blood-brain barrier permeability and oxidative stress. The pathologies were typically reversible, with dose-dependent recovery times. Behavioral changes in animals include anxiety, auditory and recognition memory deficits, and fear conditioning. The repetitive blast exposure manifests similar pathologies in animals, however, at lower blast overpressures. White matter irregularities and cortical volume and thickness alterations have been observed in neuroimaging investigations of military personnel exposed to blast. Behavioral changes in human cohorts include sleep disorders, poor motor skills, cognitive dysfunction, depression, and anxiety. Overall, this article provides a concise synopsis of current understanding, consensus, controversies, and potential future directions.

Association of mild traumatic brain injury, post-traumatic stress disorder, and other comorbidities on photosensitivity

SIGNIFICANCE

Photosensitivity is common after mild traumatic brain injury. However, this study demonstrates that photosensitivity is also impacted by common comorbidities that often occur with mild traumatic brain injury. Understanding how physical and psychological traumas impact photosensitivity can help improve provider care to trauma survivors and guide novel therapeutic interventions.

PURPOSE

This study aimed to characterize the association between mild traumatic brain injury and common comorbidities on photosensitivity in post-9/11 veterans.

METHODS

Existing data from the Translational Research Center for TBI and Stress Disorders cohort study were analyzed including traumatic brain injury history and post-traumatic stress disorder clinical diagnostic interviews; sleep quality, anxiety, and depression symptoms self-report questionnaires; and photosensitivity severity self-report from the Neurobehavioral Symptom Inventory. Analysis of covariance and multiple ordinal regression models were used to assess associations between mild traumatic brain injury and common comorbidities with photosensitivity severity.

RESULTS

Six hundred forty-one post-9/11 veterans were included in this study. An initial analysis showed that both mild traumatic brain injury and current post-traumatic stress disorder diagnosis were independently associated with higher photosensitivity ratings compared with veterans without either condition, with no interaction observed between these two conditions. Results of the ordinal regression models demonstrated positive associations between degree of photosensitivity and the number of mild traumatic brain injuries during military service and current post-traumatic stress disorder symptom severity, particularly hyperarousal symptoms, even when controlling for other factors. In addition, the degree of sleep disturbances and current anxiety symptoms were both positively associated with photosensitivity ratings, whereas depression symptoms, age, and sex were not.

CONCLUSIONS

Repetitive mild traumatic brain injury, post-traumatic stress disorder, anxiety, and sleep disturbances were all found to significantly impact photosensitivity severity and are therefore important clinical factors that eye care providers should consider when managing veterans with a history of deployment-related trauma reporting photosensitivity symptoms.

Early onset adolescent binge drinking is associated with reduced white matter integrity in post-9/11 adult veterans

Adolescence represents a critical period of neural development during which binge drinking (BD) is prevalent. Though prior work has shown that white matter (WM) integrity is susceptible to damage from excessive alcohol intake in adults, the effect of early adolescent BD on WM health in adulthood remains unknown. Veterans with a history of BD onset before age 15 [n = 49; mean age = 31.8 years; early-onset adolescent binge drinkers (EBD)] and after age 15 [n = 290; mean age = 32.2 years; late-onset adolescent binge drinkers (LBD)] were studied with diffusion tensor imaging. Group differences in fractional anisotropy (FA; movement of water molecules along the WM) and mean diffusivity (MD; average movement of water molecules) were examined as indices of WM integrity using FreeSurfer and FMRIB Software Library (FSL) processing streams. Lower FA and higher MD are thought to represent degradations in WM integrity. A reference group (RG) of social drinkers with no history of BD (n = 31) was used to provide comparative normative data. We observed widespread decreased FA and increased MD in EBDs, compared to LBDs, as well as decreased FA in the pars triangularis, lateral orbitofrontal cortex, superior frontal cortex, isthmus cingulate, and genu and splenium of the corpus callosum EBDs also had lower WM integrity compared to the RG. Adults who initiated BD during early adolescence demonstrated decreased FA and increased MD throughout the frontostriatal circuits that mediate inhibitory control and thus may result in impulsive behavior and a predisposition for developing alcohol use disorder during adulthood.

Diagnostic Accuracy of the Boston Assessment of Traumatic Brain Injury-Lifetime Clinical Interview Compared to Department of Defense Medical Records

INTRODUCTION

Since 2006, efforts have been made to increase the accurate identification of traumatic brain injuries (TBIs) in post-9/11 military personnel. The Boston Assessment of TBI-Lifetime (BAT-L) is the first validated instrument designed specifically to diagnose TBIs throughout the life span in post-9/11 Veterans. The objective was to compare the diagnostic accuracy of the BAT-L with medical records from the Department of Defense (DoD).

MATERIAL AND METHODS

Traumatic brain injury diagnosis for 153 Veterans deployed in 2011 enrolled in the Translational Research Center for TBI and Stress Disorder longitudinal cohort study from the BAT-L clinical interview was compared to DoD online medical records to determine diagnostic prevalence and injury severity for all head injury cases during deployment. Sensitivity, specificity, Cohen's kappa, and Kendall's tau-b were calculated for TBI diagnosis and severity. Concordant TBI cases and discordant TBI cases were compared using chi-square and t-test analyses. This study has been approved by VA Boston by Institutional Review Boards for human participants' protection.

RESULTS

Correspondence of TBI diagnoses from the BAT-L with DoD records was fair (κ = 0.42; sensitivity = 72.7%; specificity = 82.8%). Comparison of injury severity also showed fair correspondence (κ = 0.41). Missing TBI diagnostic data from DoD records were frequent; 43% of TBIs reported on the BAT-L did not have any documentation of assessment or diagnoses in DoD records.

CONCLUSION

This study addresses a critical gap in research by comparing the diagnostic accuracy of a validated, semi-structured clinical interview with available medical records. Diagnosis of TBIs via the BAT-L was both sensitive and specific when compared to DoD records, supporting the validity of the BAT-L for retrospective assessment of military TBI. However, diagnostic correspondence was only fair. This lack of diagnostic agreement was related to multiple factors including lack of documentation at the time of injury by DoD, differences in assessment and goals, and other combat-related motivational factors associated with failure to report injuries while deployed. Several policies have been implemented to address underreporting and under-documentation of TBIs, yet challenges remain. Recommendations for evaluating TBI are presented. Accurate diagnosis of TBI is necessary for appropriate treatment planning, as well as service-related compensation.

Adaptation in Young Military Recruits: Protocol for the Advancing Research on Mechanisms of Resilience (ARMOR) Prospective Longitudinal Study

BACKGROUND

Military services provide a unique opportunity for studying resilience, a dynamic process of successful adaptation (ie, doing well in terms of functioning and symptoms) in response to significant adversity. Despite the tremendous interest in positive adaptation among military service members, little is known about the processes underlying their resilience. Understanding the neurobiological, cognitive, and social mechanisms underlying adaptive functioning following military stressor exposure is essential for enhancing the resilience of military service members.

OBJECTIVE

The primary objective of the Advancing Research on Mechanisms of Resilience (ARMOR) longitudinal study is to characterize the trajectories of positive adaptation among young military recruits in response to basic combat training (BCT), a well-defined, uniform, and 10-week period of intense stress (aim 1), and identify promotive and protective processes contributing to individual variations in resilience (aim 2). The secondary objective is to investigate the pathways by which neurobehavioral markers of self-regulation assessed using electroencephalography and magnetic resonance imaging contribute to adaptive trajectories (aim 3).

METHODS

ARMOR is an ongoing, prospective longitudinal cohort study of young military recruits who recently joined the National Guard but have not yet shipped out for BCT. Participants (N=1201) are assessed at 5 time points over the initial >2 years of military service beginning before BCT (baseline) and followed up at 2 weeks and 6, 12, and 18 months after BCT. Participants complete web-based questionnaires assessing vulnerability and protective factors, mental health, and socioemotional functioning at each time point and a battery of neurocognitive tests at time 0. A subset of participants also complete structured diagnostic interviews and additional self-report measures and perform neurobehavioral tasks before and after BCT during electroencephalography sessions and before BCT only during magnetic resonance imaging sessions.

RESULTS

This UG3/UH3 project was initially funded in August 2017, with the UG3 pilot work completed at the end of 2018. The UH3 phase of the project was funded in March 2019. Study enrollment for the UH3 phase began on April 14, 2019, and ended on October 16, 2021. A total of 1201 participants are enrolled in the study. Follow-up data collection for the UH3 phase is ongoing and projected to continue through February 2024. We will disseminate the findings through conferences, webinars, open access publications, and communications with participants and stakeholders.

CONCLUSIONS

The ARMOR study provides a rich data set to identify the predictors and mechanisms of resilient and nonresilient outcomes in the context of military stressors, which are intended to empirically inform the development of prevention and intervention strategies to enhance the resilience of military trainees and potentially other young people facing significant life challenges.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51235.

Examining the interdisciplinary approach for treatment of persistent post-concussion symptoms in adults: a systematic review

BACKGROUND

The objective of this review is to examine the evidence for the interdisciplinary approach in treatment of persistent post-concussion symptoms in adults.

METHODS

This systematic literature search was undertaken according to the Preferred Reporting Items for Systematic and Meta-Analysis (PRISMA) guidelines. Five electronic databases were searched: CINAHL, Informit, ProQuest, PubMed and Scopus. After screening and quality assessment, the review included six studies published in English and peer-reviewed journals, between 2011 and 2021 to return contemporary evidence.

RESULTS

The results revealed that there was significant variation between measures used and the timing of the pre- and post-treatment assessment. The studies found an interdisciplinary approach to be beneficial, however, the challenges of inherent heterogeneity, lack of clarity for definitions and diagnosis, and mixed results were apparent. The interdisciplinary interventions applied in all identified studies were found to reduce post-concussion symptoms across the symptom subtypes: headache/migraine, vestibular, cognitive, ocular motor and anxiety/mood.

CONCLUSIONS

The results demonstrated evidence for a reduction in persistent post-concussion symptoms following interdisciplinary intervention. This evidence will inform health services, clinicians, sports administrators and researchers with regard to concussion clinic and rehabilitation team design and service delivery.

The Impact of Blast Exposure-With or Without Traumatic Brain Injury-on Metabolic Abnormalities in Post-9/11 Veterans

OBJECTIVE

The primary aim included explorations of: (1) the associations between the history of blast exposure (BE), close blast exposure (CBE), and blast-related traumatic brain injury (bTBI) and metabolic abnormality; and (2) the potential mediating effect of comorbid psychological and somatic conditions on these associations. The secondary aim explored the association of dose-response impact of BE, CBE, and bTBI and metabolic abnormality.

SETTING

Data were collected by the Translational Research Center for TBI and Stress Disorders (TRACTS).

PARTICIPANTS

Post-9/11 veterans from the TRACTS baseline sample who had conflict-zone deployment experience ( N = 734).

DESIGN

Cross-sectional secondary data analysis. We computed relative risks (RRs) and 95% CI using modified Poisson regression. We quantified the impact of co-occurring psychological and somatic conditions on this association using mediation analyses.

MAIN MEASURES

Exposures included BE (<100 m), CBE (<10 m), and bTBI. Metabolic abnormality outcomes included (1) overweight/obesity (defined by abnormal waist-hip ratio [WHR] and abnormal waist circumference [WC]); (2) glucose dysregulation; and (3) meeting criteria for cardiometabolic syndrome (defined by guidelines).

RESULTS

The sample was majority male (91%) and White (68%), with a mean age of 34.6 years (SD = 8.99). Most participants had 1 or more BE (83%); 48% experienced 1 or more CBE. Overweight/obesity was highly prevalent in the sample (51% had abnormal WHR and 60% abnormal WC). There was no significant direct or indirect association between BE, CBE, and bTBI and metabolic abnormalities (RRs: 0.70-1.51; P 's > .05).

CONCLUSION

Future research is needed to investigate the association of BE with metabolic abnormalities with larger, more targeted sample selection, and longer follow-up. Effective and sustainable weight management and metabolic health prevention interventions for this veteran cohort are needed.

Poorer Inhibitory Control Uniquely Contributes to Greater Functional Disability in Post-9/11 Veterans

OBJECTIVE

Post-9/11 Veterans endorse greater self-reported functional disability than 80% of the adult population. Previous studies of trauma-exposed populations have shown that increased post-traumatic stress disorder (PTSD) and depressive symptoms are consistently associated with greater disability. Additionally, poorer cognitive performance in the domain of executive functions, particularly inhibitory control, has been associated with disability, though it is unclear if this effect is independent of and/or interacts with PTSD and depression.

METHOD

Three overlapping samples of n = 582, 297, and 183 combat-deployed post-9/11 Veterans completed comprehensive assessments of executive functions, PTSD and depressive symptoms, and self-reported World Health Organization Disability Assessment Schedule-II (WHODAS II).

RESULTS

Poorer performance on measures of inhibitory control (Delis-Kaplan Executive Functioning System Color-Word Interference-CWI Test and gradual-onset Continuous Performance Test-gradCPT), but not other executive functions, were significantly associated with greater disability on the WHODAS II (ρ's = -.13 and -.13, p = .002 and .026, respectively). CWI inhibitory control measures accounted for unique variance in disability after controlling for PTSD and depressive symptoms (R2 change = 0.02, p < .001). Further, CWI significantly moderated the effect of depressive symptoms on disability, such that better inhibitory control weakened the relationship between depression and disability.

CONCLUSIONS

Inhibitory control deficits are uniquely associated with increased disability in combat-deployed post-9/11 Veterans, and better inhibitory control abilities may serve as a protective factor for depressive symptoms leading to increased disability.

KEY POINTS

Aberrant connectivity in the right amygdala and right middle temporal gyrus before and after a suicide attempt: Examining markers of suicide risk

Functional neuroimaging has the potential to help identify those at risk for self-injurious thoughts and behaviors, as well as inform neurobiological mechanisms that contribute to suicide. Based on whole-brain patterns of functional connectivity, our previous work identified right amygdala and right middle temporal gyrus (MTG) connectivity patterns that differentiated Veterans with a history of a suicide attempt (SA) from a Veteran control group. In this study, we aimed to replicate and extend our previous findings by examining whether this aberrant connectivity was present prior to and after a SA. In a trauma-exposed Veteran sample (92 % male, mean age = 34), we characterized if the right amygdala and right MTG connectivity differed between a psychiatric control sample (n = 56) and an independent sample of Veterans with a history of SA (n = 17), using fMRI data before and after the SA. Right MTG and amygdala connectivity differed between Veterans with and without a history of SA (replication), while MTG connectivity also distinguished Veterans prior to engaging in a SA (extension). In a second study, neither MTG or amygdala connectivity differed between those with current suicidal ideation (n = 27) relative to matched psychiatric controls (n = 27). These results indicate a potential stable marker of suicide risk (right MTG connectivity) as well as a potential marker of acute risk of or recent SA (right amygdala connectivity) that are independent of current ideation.

Advancing Research on Mechanisms of Resilience (ARMOR) Prospective Longitudinal Study of Adaptation in Young Military Recruits: Protocol and rationale for methods and measures

Background

Military service provides a unique opportunity for studying resilience, a dynamic process of successful adaptation (i.e., doing well in terms of functioning and symptoms) in response to significant adversity. Despite tremendous interest in positive adaptation among military service members, little is known about the processes underlying their resilience. Understanding neurobiological, cognitive, and social mechanisms underlying adaptive functioning following military stressor exposure is essential to enhance the resilience of military service members.

Objectives

The primary objective of the Advancing Research on Mechanisms of Resilience (ARMOR) longitudinal study is to characterize trajectories of positive adaptation among young military recruits in response to Basic Combat Training (BCT), a well-defined, uniform, 10-week period of intense stress (Aim 1) and identify promotive and protective processes contributing to individual variations in resilience (Aim 2). The secondary objective is to investigate pathways by which neurobehavioral markers of self-regulation assessed by electroencephalography (EEG) and magnetic resonance imaging (MRI) contribute to adaptive trajectories (Aim 3).

Methods

ARMOR is an ongoing, prospective longitudinal cohort study of young military recruits who recently joined the National Guard but have not yet shipped for BCT. Participants (N=1,201) are assessed at five timepoints over the initial 2+ years of military service beginning before BCT (baseline) and followed up at 2 weeks, 6, 12, and 18 months post-BCT. At each time point, participants complete online questionnaires assessing vulnerability and protective factors, mental health and social-emotional functioning, and, at Time 0 only, a battery of neurocognitive tests. A subset of participants also complete structured diagnostic interviews, additional self-report measures, and perform neurobehavioral tasks before and after BCT during EEG sessions, and, at pre-BCT only, during MRI sessions.

Results

Study enrollment began April 14, 2019 and ended in October 16, 2021. A total of 1,201 participants are enrolled in the study (68.9% male; mean age = 18.9, SD = 3.0). Follow-up data-collection is ongoing and projected to continue through March 2024. We will disseminate findings through conferences, webinars, open access publications, and communications with participants and stakeholders.

Conclusions

Results are expected to elucidate how young military recruits adapt to military stressors during the initial years of military service. Understanding positive adaptation of military recruits in the face of BCT has implications for developing prevention and intervention strategies to enhance resilience of military trainees and potentially other young people facing significant life challenges.

Neurobiological and genetic correlates of the dissociative subtype of posttraumatic stress disorder

Approximately 10%-30% of individuals with posttraumatic stress disorder (PTSD) exhibit a dissociative subtype of the condition defined by symptoms of depersonalization and derealization. This study examined the psychometric evidence for the dissociative subtype of PTSD in a sample of young, primarily male post-9/11-era Veterans (n = 374 at baseline and n = 163 at follow-up) and evaluated its biological correlates with respect to resting state functional connectivity (default mode network [DMN]; n = 275), brain morphology (hippocampal subfield volume and cortical thickness; n = 280), neurocognitive functioning (n = 337), and genetic variation (n = 193). Multivariate analyses of PTSD and dissociation items suggested a class structure was superior to dimensional and hybrid ones, with 7.5% of the sample comprising the dissociative class; this group showed stability over 1.5 years. Covarying for age, sex, and PTSD severity, linear regression models revealed that derealization/depersonalization severity was associated with: decreased DMN connectivity between bilateral posterior cingulate cortex and right isthmus (p = .015; adjusted-p [padj] = .097); increased bilateral whole hippocampal, hippocampal head, and molecular layer head volume (p = .010-.034; padj = .032-.053); worse self-monitoring (p = .018; padj = .079); and a candidate genetic variant (rs263232) in the adenylyl cyclase 8 gene (p = .026), previously associated with dissociation. Results converged on biological structures and systems implicated in sensory integration, the neural representation of spatial awareness, and stress-related spatial learning and memory, suggesting possible mechanisms underlying the dissociative subtype of PTSD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Sleep Quality Disturbances Are Associated with White Matter Alterations in Veterans with Post-Traumatic Stress Disorder and Mild Traumatic Brain Injury

Sleep disturbances are strongly associated with mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD). PTSD and mTBI have been linked to alterations in white matter (WM) microstructure, but whether poor sleep quality has a compounding effect on WM remains largely unknown. We evaluated sleep and diffusion magnetic resonance imaging (dMRI) data from 180 male post-9/11 veterans diagnosed with (1) PTSD (n = 38), (2) mTBI (n = 25), (3) comorbid PTSD+mTBI (n = 94), and (4) a control group with neither PTSD nor mTBI (n = 23). We compared sleep quality (Pittsburgh Sleep Quality Index, PSQI) between groups using ANCOVAs and calculated regression and mediation models to assess associations between PTSD, mTBI, sleep quality, and WM. Veterans with PTSD and comorbid PTSD+mTBI reported poorer sleep quality than those with mTBI or no history of PTSD or mTBI (p = 0.012 to <0.001). Poor sleep quality was associated with abnormal WM microstructure in veterans with comorbid PTSD+mTBI (p < 0.001). Most importantly, poor sleep quality fully mediated the association between greater PTSD symptom severity and impaired WM microstructure (p < 0.001). Our findings highlight the significant impact of sleep disturbances on brain health in veterans with PTSD+mTBI, calling for sleep-targeted interventions.

Genetic Risk for Alzheimer Disease and Plasma Tau Are Associated With Accelerated Parietal Cortex Thickness Change in Middle-Aged Adults

Background and Objectives

Neuroimaging and biomarker studies in Alzheimer disease (AD) have shown well-characterized patterns of cortical thinning and altered biomarker concentrations of tau and β-amyloid (Aβ). However, earlier identification of AD has great potential to advance clinical care and determine candidates for drug trials. The extent to which AD risk markers relate to cortical thinning patterns in midlife is unknown. The first objective of this study was to examine cortical thickness change associated with genetic risk for AD among middle-aged military veterans. The second objective was to determine the relationship between plasma tau and Aβ and change in brain cortical thickness among veterans stratified by genetic risk for AD.

Methods

Participants consisted of post-9/11 veterans (N = 155) who were consecutively enrolled in the Translational Research Center for TBI and Stress Disorders prospective longitudinal cohort and were assessed for mild traumatic brain injury (TBI) and posttraumatic disorder (PTSD). Genome-wide polygenic risk scores (PRSs) for AD were calculated using summary results from the International Genomics of Alzheimer's Disease Project. T-tau and Aβ40 and Aβ42 plasma assays were run using Simoa technology. Whole-brain MRI cortical thickness change estimates were obtained using the longitudinal stream of FreeSurfer. Follow-up moderation analyses examined the AD PRS × plasma interaction on change in cortical thickness in AD-vulnerable regions.

Results

Higher AD PRS, signifying greater genetic risk for AD, was associated with accelerated cortical thickness change in a right hemisphere inferior parietal cortex cluster that included the supramarginal gyrus, angular gyrus, and intraparietal sulcus. Higher tau, but not Aβ42/40 ratio, was associated with greater cortical thickness change among those with higher AD PRS. Mild TBI and PTSD were not associated with cortical thickness change.

Discussion

Plasma tau, particularly when combined with genetic stratification for AD risk, can be a useful indicator of brain change in midlife. Accelerated inferior parietal cortex changes in midlife may be an important factor to consider as a marker of AD-related brain alterations.

Surveying the Landscape: A Review of Longitudinal TBI Studies in Service Member and Veteran Populations

Traumatic brain injury (TBI) is known to be a signature wound of the post-9/11 conflicts. In response, the U.S. Department of Defense (DOD) and other federal organizations have directed significant investments toward TBI research on characterizing injury populations and understanding long-term outcomes. To address legislative requirements and research gaps, several observational, longitudinal TBI studies were initiated as an effective means of investigating TBI clinical management, outcomes, and recovery. This review synthesizes the landscape (i.e., requirements and gaps, infrastructure, geography, timelines, TBI severity definitions, military and injury populations of interest, and measures) of DOD-funded longitudinal TBI studies being conducted in service member and veteran (SMV) populations. Based on the landscape described here, we present recommended actions and solutions that would allow a consolidated and cooperative future state of longitudinal TBI research, optimized continued investments, and advances in the state of the science without redundancy.

Network analysis of mild traumatic brain injury, persistent neurobehavioral and psychiatric symptoms, and functional disability among recent-era United States veterans

Recent-era U.S. veterans are clinically complex, with a high prevalence of co-occurring mild traumatic brain injury (mTBI), psychiatric conditions, and behavioral dysfunction. The current study examined the direct and indirect associations between mTBI and persistent neurobehavioral, psychiatric, and functional disability symptoms among recent-era U.S. veterans and service members (n = 648). We evaluated the postconcussive syndrome (PCS) potential causal model with two network analysis modeling approaches. Separate analyses were conducted for military mTBI and lifetime mTBI. An exploratory factor analysis was conducted to limit topological overlap in the network analysis. The most influential symptoms (i.e., the unique variables most strongly associated with the rest of the network) in the military mTBI network were behavioral disengagement, expected influence (EI) = 1.10; cognitive difficulties, EI = 1.08; agitation/irritability, EI = 1.05; and PTSD-related reexperiencing and avoidance symptoms, EI = 0.98. After accounting for other symptoms, mTBI was only minimally informative, EI = 0.34. Additionally, military mTBI did not moderate the association between symptoms or the overall connectivity of the network. The results for lifetime mTBI were consistent with those for military mTBI. The present analyses identified a variety of behavioral, cognitive, and emotional symptoms that play an important role in understanding comorbidity and daily functioning among recent-era U.S. veterans. Associations between cumulative mTBI that occurred in civilian or military settings were indirect and relatively small in magnitude. The current results add to a growing literature raising doubts about the PCS model.

For whom the bell tolls: psychopathological and neurobiological correlates of a DNA methylation index of time-to-death

Psychopathology is a risk factor for accelerated biological aging and early mortality. We examined associations between broad underlying dimensions of psychopathology (reflecting internalizing and externalizing psychiatric symptoms), PTSD, and age-adjusted GrimAge ("GrimAge residuals"), a DNA methylation biomarker of mortality risk relative to age. We also examined neurobiological correlates of GrimAge residuals, including neurocognitive functioning, blood-based biomarkers (of inflammation, neuropathology, metabolic disease), and cortical thickness. Data from two independent trauma-exposed military cohorts (n = 647 [62.9% male, Mage = 52], n = 434 [90% male, Mage = 32]) were evaluated using linear regression models to test associations between GrimAge residuals, psychopathology, and health correlates. Externalizing psychopathology significantly predicted GrimAge residuals in both cohorts (ps < 0.028). PTSD predicted GrimAge residuals in the younger (p = 0.001) but not the older cohort. GrimAge residuals were associated with several neurobiological variables available in the younger cohort, including cognitive disinhibition (padj = 0.021), poorer memory recall (padj = 0.023), cardiometabolic pathology (padj < 0.001), oxidative stress (padj = 0.003), astrocyte damage (padj = 0.021), inflammation (C-reactive protein: padj < 0.001; IL-6: padj < 0.001), and immune functioning (padj < 0.001). A subset of inflammatory and neuropathology analytes were available in the older cohort and showed associations with GrimAge residuals (IL-6: padj < 0.001; TNF-α: padj < 0.001). GrimAge residuals were also associated with reduced cortical thickness in right lateral orbitofrontal cortex (padj = 0.018) and left fusiform gyrus (padj = 0.030), which are related to emotion regulation and facial recognition, respectively. Psychopathology may be a common risk factor for elevated mortality risk. GrimAge could help identify those at risk for adverse health outcomes and allow for early disease identification and treatment.

PTSD symptomatology is selectively associated with impaired sustained attention ability and dorsal attention network synchronization

Posttraumatic Stress Disorder (PTSD) symptomatology is associated with dysregulated sustained attention, which produces functional impairments. Performance on sustained attention paradigms such as continuous performance tasks are influenced by both the ability to sustain attention and response strategy. However, previous studies have not dissociated PTSD-related associations with sustained attention ability and strategy, which limits characterization of neural circuitry underlying PTSD-related attentional impairments. Therefore, we characterized and replicated PTSD-related associations with sustained attention ability and response strategy in trauma-exposed Veterans, which guided characterization of PTSD-related differences in neural circuit function. In Study 1, PTSD symptoms were selectively associated with reduced sustained attention ability, but not more impulsive response strategies. In Study 2, we utilized task and resting-state fMRI to characterize neural circuitry underlying PTSD-related differences in sustained attention ability. Both PTSD symptomatology and sustained attention ability exhibited converging associations with reduced dorsal attention network (DAN) synchronization to endogeneous attentional fluctuations. Post-hoc time course analyses demonstrated that PTSD symptoms were most accurately characterized by delayed, rather than globally reduced, DAN synchronization to endogenous attentional fluctuations. Together, these findings suggest that PTSD symptomatology may selectively impair sustained attention ability by disrupting proactive engagement of attentional control circuitry.

The association between blast exposure and transdiagnostic health symptoms on systemic inflammation

Chronic elevation of systemic inflammation is observed in a wide range of disorders including PTSD, depression, and traumatic brain injury. Although previous work has demonstrated a link between inflammation and various diagnoses separately, few studies have examined transdiagnostic symptoms and inflammation within the same model. The objective of this study was to examine relationships between psychiatric and health variables and systemic inflammation and to determine whether mild traumatic brain injury (mTBI) and/or exposure to blast munitions moderate these relationships. Confirmatory factor analysis in a large sample (N = 357) of post-9/11 Veterans demonstrated a good fit to a four-factor model reflecting traumatic stress, affective, somatic, and metabolic latent variables. Hierarchical regression models revealed that each of the latent variables were associated with higher levels of systemic inflammation. However, the strongest relationship with inflammation emerged among those who had both war-zone blast exposures and metabolic dysregulation, even after adjusting for mental health latent variables. Exploratory analyses showed that blast exposure was associated with metabolic dysregulation in a dose-response manner, with self-reported closer blast proximity associated with the greatest metabolic dysregulation. Together, these results provide a greater understanding of the types of symptoms most strongly associated with inflammation and underscore the importance of maintaining a healthy lifestyle to reduce the impact of obesity and other metabolic symptoms on future chronic disease in younger to middle-aged Veterans.

Post-traumatic stress disorder and depression are uniquely associated with disability and life dissatisfaction in post-9/11 veterans

Veterans who served in post-9/11 conflicts and experience deployment trauma sequelae frequently endorse disability and dissatisfaction with life. Although correlated, disability and life dissatisfaction represent distinct constructs with separate implications for quality of life. We examined associations between deployment trauma sequelae, disability and life dissatisfaction in 288 post-9/11 Veterans. Participants completed assessments of psychiatric, somatic and social functioning. Self-reports evaluating disability and life dissatisfaction were used to group participants based on established criteria (i.e., Disability and Dissatisfaction, Disability Only, Dissatisfaction Only, or No Disability or Dissatisfaction). Multinomial logistic regressions revealed that greater post-traumatic stress disorder (PTSD) and depressive symptom severity were independently associated with increased odds of being in the Disability and Dissatisfaction group, the Disability Only group and the Dissatisfaction Only group, relative to the No Disability or Dissatisfaction group. Number of prior mild traumatic brain injuries (mTBI) was not associated with disability or dissatisfaction after accounting for other trauma sequelae. Social support attenuated the relationship between depression and membership in the Disability and Dissatisfaction group. Participants who reported greater dissatisfaction than disability endorsed greater depression and mTBI frequency. Overall, PTSD and depression convey a heightened risk of both disability and life dissatisfaction, while social support may be protective.

An executive function subtype of PTSD with unique neural markers and clinical trajectories

Previous work identified a cognitive subtype of PTSD with impaired executive function (i.e., impaired EF-PTSD subtype) and aberrant resting-state functional connectivity between frontal parietal control (FPCN) and limbic (LN) networks. To better characterize this cognitive subtype of PTSD, this study investigated (1) alterations in specific FPCN and LN subnetworks and (2) chronicity of PTSD symptoms. In a post-9/11 veteran sample (N = 368, 89% male), we identified EF subgroups using a standardized neuropsychological battery and a priori cutoffs for impaired, average, and above-average EF performance. Functional connectivity between two subnetworks of the FPCN and three subnetworks of the LN was assessed using resting-state fMRI (n = 314). PTSD chronicity over a 1-2-year period was assessed using a reliable change index (n = 175). The impaired EF-PTSD subtype had significantly reduced negative functional connectivity between the FPCN subnetwork involved in top-down control of emotion and two LN subnetworks involved in learning/memory and social/emotional processing. This impaired EF-PTSD subtype had relatively chronic PTSD, while those with above-average EF and PTSD displayed greater symptom reduction. Lastly, FPCN-LN subnetworks partially mediated the relationship between EF and PTSD chronicity (n = 121). This study reveals (1) that an impaired EF-PTSD subtype has a specific pattern of FPCN-LN subnetwork connectivity, (2) a novel above-average EF-PTSD subtype displays reduced PTSD chronicity, and (3) both cognitive and neural functioning predict PTSD chronicity. The results indicate a need to investigate how individuals with this impaired EF-PTSD subtype respond to treatment, and how they might benefit from personalized and novel approaches that target these neurocognitive systems.

Contributory Etiologies to Cognitive Performance in Multimorbid Post-9/11 Veterans: The Deployment Trauma Phenotype

OBJECTIVE

This study examined cognitive functioning in post-9/11 Veterans with the deployment trauma phenotype (DTP), comprised of co-occurring diagnoses of depressive disorder (major depressive disorder and or persistent depressive disorder/dysthymia), posttraumatic stress disorder (PTSD), and mild traumatic brain injury (mTBI), using objective neuropsychological measures.

METHOD

Participants included a cross-sectional sample of 399 post-9/11 Veterans who completed clinical interviews and neuropsychological tests as part of a larger study at VA Boston Healthcare System. Confirmatory factor analysis identified four cognitive domains: attention, cognitive control/processing speed, episodic memory, and cognitive flexibility. Veterans with DTP and its constituent diagnoses in isolation, two-way diagnostic combinations, and no constituent diagnoses were compared.

RESULTS

Veterans with DTP had a twofold increased prevalence for below average performance in cognitive control/processing speed compared with those with no constituent diagnoses (prevalence ratios [PRs] = 2.04; 95% confidence interval [CI]: 1.03-4.05). The PTSD + depressive disorder group also had a twofold increased prevalence for below average performance in episodic memory (PR = 2.16; 95% CI: 1.05-4.43).

CONCLUSIONS

The deployment trauma phenotype is associated with clinically significant decrease in cognitive control/processing speed in post-9/11 Veterans. Comorbid PTSD and depressive disorder negatively impacted performances in episodic memory. Mild TBI alone showed no cognitive deficits. Clinical interventions should target psychiatric symptoms with a transdiagnostic approach to address this multimorbid population.

Associations between Post-Traumatic stress disorder symptoms and automobile driving behaviors: A review of the literature

Human factors are responsible for most motor vehicle accidents that occur on the road. Recent work suggests that symptoms of posttraumatic stress disorder (PTSD) are linked to reduced driving safety, yet none have provided a comprehensive review of this small, emerging literature. The present review identified twenty-two studies reporting associations between PTSD and driving behaviors. Among these, longitudinal designs (k = 3) and studies using objective driving performance measures (e.g., simulators) (k = 2) were rare. Most studies (k = 18) relied on brief screener measures of PTSD status/symptoms or a prior chart diagnosis, while few used a standardized structured interview measure to determine PTSD status (k = 4), and only a small number of studies assessed PTSD symptom clusters (k = 7). PTSD was most frequently associated with increased rates of hostile driving behaviors (e.g., cutting off others), unintentional driving errors (e.g., lapses in attention) and negative thoughts and emotions experienced behind the wheel. Findings regarding risk of motor vehicle accident and driving-related legal issues were variable, however relatively few studies (k = 5) explored these constructs. Future directions are discussed, including the need for work focused on concurrent PTSD symptom/driving-related changes, more comprehensive PTSD and driving assessment, and consideration of the contributions of comorbid traumatic brain injury history and other neurological and psychiatric conditions on driving outcomes.

Associations between changes in somatic and psychiatric symptoms and disability alterations in recent-era U.S. veterans

Cross-sectional work suggests that deployment-related posttraumatic sequelae are associated with increased disability in U.S. veterans deployed following the September 11, 2001 (9/11), terrorist attacks. However, few studies have examined the psychiatric and somatic variables associated with changes in functional disability over time. A total of 237 post-9/11 veterans completed comprehensive assessments of psychiatric and cognitive functioning, as well as a disability questionnaire, at baseline and 2-year follow-up. At baseline, higher levels of PTSD, depressive, and pain-related symptoms were associated with baseline global functional disability, semipartial r² = .036-.044. Changes in symptoms of PTSD, depression, pain, and sleep, but not anxiety or alcohol use, were independently associated with changes in functional disability, semipartial r² = .017-.068. Baseline symptoms of these conditions were unrelated to changes in disability, and cognitive performance was unrelated to disability at any assessment point. Together, this suggests that changes in psychiatric and somatic symptoms are tightly linked with changes in functional disability and should be frequently monitored, and even subclinical symptoms may be a target of intervention.

Advancing PTSD Diagnosis and the Treatment of Trauma in Humanitarian Emergencies via Mobile Health: Protocol for a Proof-of-Concept Non-Randomized Controlled Trial

BACKGROUND

Decentralized health systems in Low and Middle-Income Countries (LMICs) impacted by humanitarian crises lack resources and a qualified workforce to attend to the overwhelming demand for mental health care in emergencies. Innovative approaches that are safe, cost-effective, and scalable are needed to address the burden of traumatic stress brought by emergencies. High mobile phone ownership rates combined with the precision of neural, cognitive, and biometric measures of trauma and its feasible integration with Artificial Intelligence (AI) makes digital application (app) interventions a promising pathway to promote precision diagnosis and high-impact care.

OBJECTIVE

The aims of this study are to advance methods for the objective diagnosis and treatment of trauma in emergencies across LMICs by examining (i) neural, cognitive, and biometric markers and (ii) the efficacy of the eResilience App, a neuroscience-informed mobile health mental health app intervention, via changes in clinical symptomatology, cognitive performance, and brain activity.

METHODS

Trauma-exposed African refugees residing in Australia were selected for this study. A research software version of the eResilience App with advanced monitoring capabilities was designed for the trial. Participants completed the eResilience App at home during a seven-day period. Clinical, cognitive, and electrophysiological data were collected during baseline and post-test to examine biomarkers of trauma and the efficacy of the proposed digital intervention for the treatment of trauma and its potential outcomes including depression, anxiety, physical symptoms, self-harm, substance misuse, and cognitive impairment. In addition, biofeedback, wellbeing, and subjective stress data points were collected via the app during the treatment week, followed by clinical interviews at 1, 3, 6 and 12-months post-intervention.

RESULTS

Data collection was conducted between 2018 and 2020. A total n=100 participants exposed to war were screened, n= 75 were enrolled and assigned to a trauma-exposed control (n=38) or Posttraumatic Stress Disorder (PTSD) condition (n=37), and n= 70 completed all baseline, treatment, and post-test assessments. A total n=62 of the n=70 who completed the intervention opted to enrol in the 3, 6 and 12-month follow-ups. Data collection is complete, and results are being prepared for publication. If proven efficacious, this proof-of-concept clinical trial will inform fully powered randomized clinical trials in LMICs to further develop AI-powered, app-based diagnostic and prognostic features, and determine the app's cross-cultural efficacy for the treatment of trauma in emergency settings.

CONCLUSIONS

This protocol provides researchers with a comprehensive background of the study rationale, a detailed guideline for replication studies interested in examining the feasibility and the efficacy of the eResilience App across varied demographics, and a robust framework for investigations of low-cost objective diagnostic markers in mental health interventions. Methodological limitations and suggestions are also provided.

CLINICALTRIAL

Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12616001205426. Universal Trial Number (UTN): U1111-1180-0347.

Accelerated longitudinal cortical atrophy in OEF / OIF / OND veterans with severe PTSD and the impact of comorbid TBI

Veterans who deployed in support of Operation Enduring Freedom (OEF), Iraqi Freedom (OIF), and New Dawn (OND) commonly experience severe psychological trauma, often accompanied by physical brain trauma resulting in mild traumatic brain injury (mTBI). Prior studies of individuals with posttraumatic stress disorder (PTSD) have revealed alterations in brain structure, accelerated cellular aging, and impacts on cognition following exposure to severe psychological trauma and potential interactive effects of military‐related mTBI. To date, however, little is known how such deployment‐related trauma changes with time and age of injury of the affected veteran. In this study, we explored changes in cortical thickness, volume, and surface area after an average interval of approximately 2 years in a cohort of 254 OEF/OIF/OND Veterans ranging in age from 19 to 67 years. Whole‐brain vertex‐wise analyses revealed that veterans who met criteria for severe PTSD (Clinician‐Administered PTSD Scale ≥60) at baseline showed greater negative longitudinal changes in cortical thickness, volume, and area over time. Analyses also revealed a significant severe‐PTSD by age interaction on cortical measures with severe‐PTSD individuals exhibiting accelerated cortical degeneration with increasing age. Interaction effects of comorbid military‐related mTBI within the severe‐PTSD group were also observed in several cortical regions. These results suggest that those exhibiting severe PTSD symptomatology have accelerated atrophy that is exacerbated with increasing age and history of mTBI.

Methylation of the AIM2 gene: An epigenetic mediator of PTSD-related inflammation and neuropathology plasma biomarkers

BACKGROUND

Posttraumatic stress disorder (PTSD) is associated with inflammation and various forms of chronic disease. The Absent in Melanoma 2 (AIM2) gene has been implicated in mechanisms of inflammation and anxiety, and methylation at a particular locus in this gene (cg10636246) has previously been shown to influence the association between PTSD and elevated C-reactive protein levels in blood.

METHOD

We tested if this association might extend to other indicators of inflammation and to plasma-based measures of neuropathology in a cohort of post-9/11 US military veterans. Using a Bayesian approach, mediation models were tested cross-sectionally (n = 478) and longitudinally (n = 298). Peripheral markers of inflammation and neuropathology were measured with ultra-sensitive Single Molecule Array (Simoa®) technology.

RESULTS

Analyses revealed indirect effects of PTSD symptom severity on peripheral indices of both inflammation (interleukin [IL]6, IL-10, tumor necrosis factor-α; indirect standardized [std.] ß range = 0.018-0.023, all p-values adjusted for multiple testing [padj ] < 0.05) and neuropathology (neurofilament light [NFL]; indirect std. ß = -0.018, padj  = 0.02) via AIM2 methylation. This indirect effect was also evident when predicting IL-10 at a follow-up assessment (indirect std. ß = -0.018, padj  = 0.04) controlling for baseline IL-10.

CONCLUSIONS

Given that AIM2 methylation mediated the association between PTSD symptoms and multiple inflammatory and neuropathology markers, our results suggest that AIM2 methylation may offer clinical utility for indexing risk for adverse health outcomes associated with these peripheral indices of inflammation and neuropathology. Results also suggest a possible shared etiology underlying the frequent co-occurrence of inflammation and neuropathology.

Research utility of a CAPS-IV and CAPS-5 hybrid interview: Posttraumatic stress symptom and diagnostic concordance in recent-era U.S. veterans

The Clinician-Administered PTSD Scale (CAPS) is used to measure posttraumatic stress symptoms (PTSS) and diagnose posttraumatic stress disorder (PTSD). However, its use, particularly in settings involving longitudinal assessment, has been complicated by changes in the diagnostic criteria between the fourth and fifth editions of the Diagnostic and Statistical Manual of Mental Disorders (i.e., DSM-IV and DSM-5, respectively). The current sample included trauma-exposed U.S. veterans who were deployed in support of military operations following the September 11, 2001, terrorist attacks (N = 371) and were enrolled in a longitudinal study focused on deployment-related stress and traumatic brain injury. A hybrid clinical interview using item wording from the CAPS for DSM-IV (CAPS-IV) with the addition of items unique to the CAPS for DSM-5 (CAPS-5) was used to assess both DSM-IV and DSM-5 PTSD diagnostic criteria, allowing for the calculation of separate total scores and diagnoses. Diagnostic agreement, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and interrater reliability between CAPS-IV and CAPS-5 were evaluated for the entire sample and stratified by gender. We found high diagnostic agreement (92.9%-95.4%), sensitivity (94.4%-98.2%), specificity (91.7%-92.8%), PPV (89.5%-93.0%), NPV (95.7%-98.1%), and interrater reliability,κ = 0.86-0.91,) for both men and women. The current study supports the use of a hybrid PTSD diagnostic interview assessing both DSM-IV and DSM-5 diagnostic criteria, particularly in situations such as longitudinal studies that may require a feasible method of incorporating changes in diagnostic criteria from the DSM-IV to the DSM-5.

Plasma biomarkers associated with deployment trauma and its consequences in post-9/11 era veterans: initial findings from the TRACTS longitudinal cohort

Mild traumatic brain injury (mTBI) is among the most common injuries sustained by post-9/11 veterans; however, these injuries often occur within the context of psychological trauma. Blast exposure, even in the absence of a diagnosable TBI, leads to changes in neural connectivity and congitive functioning. Therefore, considering clinical comorbidities and injury characteristics is critical to understanding the long-term effects of mTBI. Research is moving towards identifying diagnostic and prognostic blood-based biomarkers for TBI; however, few studies include other prevalent clinical and medical comorbidities related to deployment. Here, we present the initial cross-sectional relationships between plasma biomarkers, clinical, and medical comorbidities in a well-characterized longitudinal sample of 550 post-9/11 veteran men and women. We examined biomarkers associated with inflammation (interleukin 6 and 10, tumor necrosis factor α, and eotaxin) and neurodegeneration (neurofilament light, glial fibrillary acidic protein (GFAP), tau, brain derived neurotrophic factor, amyloid ß 40 and 42, phosphorylated neurofilament heavy chain, and neuron specific enolase). Univariate analyses of covariance (ANCOVA) were conducted to determine mean level differences between close blast (blasts that occur within 0-10 meters) and mTBI groups. Our primary findings were twofold: (1) Inflammatory markers were consistently higher in participants exposed to close blasts and were strongly related to deployment-related psychopathology. (2) GFAP was consistently lower in participants exposed to blast and mTBI and lower GFAP was associated with more severe psychological symptoms. More research is clearly needed; however, our findings indicate that chronic increased inflammation and decreased GFAP may be related to close blast exposure.

Perspectives on Primary Blast Injury of the Brain: Translational Insights Into Non-inertial Low-Intensity Blast Injury

Most traumatic brain injuries (TBIs) during military deployment or training are clinically "mild" and frequently caused by non-impact blast exposures. Experimental models were developed to reproduce the biological consequences of high-intensity blasts causing moderate to severe brain injuries. However, the pathophysiological mechanisms of low-intensity blast (LIB)-induced neurological deficits have been understudied. This review provides perspectives on primary blast-induced mild TBI models and discusses translational aspects of LIB exposures as defined by standardized physical parameters including overpressure, impulse, and shock wave velocity. Our mouse LIB-exposure model, which reproduces deployment-related scenarios of open-field blast (OFB), caused neurobehavioral changes, including reduced exploratory activities, elevated anxiety-like levels, impaired nesting behavior, and compromised spatial reference learning and memory. These functional impairments associate with subcellular and ultrastructural neuropathological changes, such as myelinated axonal damage, synaptic alterations, and mitochondrial abnormalities occurring in the absence of gross- or cellular damage. Biochemically, we observed dysfunctional mitochondrial pathways that led to elevated oxidative stress, impaired fission-fusion dynamics, diminished mitophagy, decreased oxidative phosphorylation, and compensated cell respiration-relevant enzyme activity. LIB also induced increased levels of total tau, phosphorylated tau, and amyloid β peptide, suggesting initiation of signaling cascades leading to neurodegeneration. We also compare translational aspects of OFB findings to alternative blast injury models. By scoping relevant recent research findings, we provide recommendations for future preclinical studies to better reflect military-operational and clinical realities. Overall, better alignment of preclinical models with clinical observations and experience related to military injuries will facilitate development of more precise diagnosis, clinical evaluation, treatment, and rehabilitation.

Neural Correlates of Traumatic Brain Injury in Women Survivors of Intimate Partner Violence: A Structural and Functional Connectivity Neuroimaging Study

OBJECTIVE

More than one-third of women in the United States experience intimate partner violence (IPV) in their lifetime, increasing their risk for traumatic brain injury (TBI). Despite the prevalence of TBI among IPV survivors, research is sparse in comparison with parallel populations (eg, military, accidents, sports). This pilot study aimed to provide a preliminary investigation of the effect of TBI on brain morphometry and resting-state functional connectivity in women who experience IPV.

PARTICIPANTS

A total of 45 community-dwelling women survivors of IPV who screened positive for posttraumatic stress disorder (PTSD).

DESIGN

Participants completed comprehensive assessments of trauma exposure, PTSD, TBI history, and brain neurological health. Twenty-three participants (51.1%) met diagnostic criteria for lifetime TBI. Of these, 15 participants experienced 1 or more TBIs resulting from IPV. The remaining participants experienced TBI from non-IPV exposures (eg, sports/motor vehicle accident). Surface-based neuroimaging analyses were performed to examine group differences in cortical thickness and in functional connectivity of amygdala and isthmus cingulate seeds to examine emotion regulation and the default mode network, respectively.

MAIN MEASURES

Boston Assessment of Traumatic Brain Injury-Lifetime for Intimate Partner Violence (BAT-L/IPV); Clinician Administered PTSD Scale (CAPS); structural and functional neuroimaging.

RESULTS

History of lifetime TBI in women IPV survivors was associated with differences in cortical thickness as well as functional connectivity between the isthmus cingulate seed and a variety of regions, including superior parietal and frontal cortices. Individuals with IPV-related TBI showed lower cortical thickness in the right paracentral gyrus than individuals with TBI from other non-IPV etiologies.

CONCLUSION

Significant differences in brain structure and connectivity were observed in individuals with IPV and TBI. A lower mean cortical thickness of the paracentral gyrus was associated with TBI due to IPV than TBI from other etiologies. Although preliminary, findings from this pilot study present a step toward identifying potential mechanisms by which IPV and TBI secondary to IPV impact brain health in women.

Punishment and reward normalize error-related cognitive control in PTSD by modulating salience network activation and connectivity

Posttraumatic Stress Disorder (PTSD) symptomatology disrupts inhibitory control during sustained attention. However, PTSD-related inhibitory control deficits are partially ameliorated when punishments and rewards are administered based on task performance, which suggests motivational processes contribute to these deficits. Additionally, PTSD may also impair error-related cognitive control following inhibitory control failures as measured by post-error slowing (PES). However, it remains unclear if motivational processes also contribute to impaired error-related cognitive control in PTSD. Using an incentivized sustained attention paradigm in two independent samples of post-9/11 veterans, we characterized PTSD-related differences in PES during both non-motivated conditions (no task-based incentives) and motivated conditions (task-based rewards and punishments). In Study 1 (n = 139), PTSD symptom severity was modestly associated with smaller PES in the non-motivated condition, whereas no PTSD-related association was observed in the motivated condition. In Study 2 (n = 35), we replicated and extended these results by using fMRI to characterize modulation of the triple network system comprised of the Salience Network (SN), Frontoparietal Control Network (FPCN), and Default Mode Network (DMN). In the non-motivated condition, PTSD symptom severity was associated with non-specific SN and FPCN hyperactivation during both failed and successful inhibitory control. In the motivated condition, PTSD symptom severity was associated with greater focal activation of both the SN and Superior Parietal Lobule cluster (an FPCN node) during punished inhibitory control failures and weaker SN-FPCN connectivity during rewarded inhibitory control successes. Together, these results suggest that dysregulated motivational processes in PTSD may contribute to impaired error-related cognitive control.

Network Analysis of Research on Mild Traumatic Brain Injury in US Military Service Members and Veterans During the Past Decade (2010-2019)

OBJECTIVE

To evaluate trends in the extant literature on mild traumatic brain injury (mTBI) in military service members and veterans using network analysis based on a comprehensive search of original, peer-reviewed research articles involving human participants published between January 1, 2010, and December 31, 2019. Specifically, we employed network analysis to evaluate associations in the following areas: (1) peer-reviewed journals, (2) authors, (3) organizations/institutions, and (4) relevant key words.

PARTICIPANTS

Included studies were published in peer-reviewed journals available on Web of Science database, using US military service members or veterans.

DESIGN

Bibliometric network analytical review.

MAIN MEASURES

Outcomes for each analysis included number of articles, citations, total link strength, and clusters.

RESULTS

The top publishing journals were (1) Journal of Head Trauma and Rehabilitation, (2) Military Medicine, (3) Brain Injury, (4) Journal of Neurotrauma, and (5) Journal of Rehabilitation Research and Development. The top publishing authors were (1) French, (2) Lange, (3) Cooper, (4) Vanderploeg, and (5) Brickell. The top research institutions were (1) Defense and Veterans Brain Injury Center, (2) Uniformed Services University of the Health Sciences, (3) University of California San Diego, (4) Walter Reed National Military Medical Center, and (5) Boston University. The top co-occurring key words in this analysis were (1) posttraumatic stress disorder (PTSD), (2) persistent postconcussion symptoms (PPCS), (3) blast injury, (4) postconcussion syndrome (PCS), and (5) Alzheimer's disease.

CONCLUSIONS

The results of this network analysis indicate a clear focus on veteran health, as well as investigations on chronic effects of mTBI. Research in civilian mTBI indicates that delaying treatment for symptoms and impairments related to mTBI may not be the most precise treatment strategy. Increasing the number of early, active, and targeted treatment trials in military personnel could translate to meaningful improvements in clinical practices for managing mTBI in this population.

Co-occurrence of pain and dyspnea in Veterans with COPD: Relationship to functional status and a pilot study of neural correlates using structural and functional magnetic resonance imaging

Persons with COPD experience co-occurring dyspnea and pain. Little is known about the relationship between symptom co-occurrence with physical activity (PA) and exercise. Novel diagnostic tools are needed for accurate symptom discrimination. In this secondary analysis, we examined relationships between baseline assessments of pain, dyspnea, objectively measured PA, and exercise capacity in persons with COPD who previously enrolled in three PA studies. Pain was assessed with the bodily pain domain of the Veterans RAND-36 (VR-36), and dyspnea with the modified Medical Research Council (mMRC) scale. Average daily step count was assessed with the Omron HJ-720ITC or FitBit Zip pedometer, and exercise capacity with 6-minute walk test (6MWT). We also conducted a pilot neuroimaging study. Neuroimaging data were acquired on a Siemens 3-Tesla Magnetom Prismafit whole-body scanner. Analysis of variance assessed trends in daily step count and 6MWT distance across categories of co-occurring pain and dyspnea. General linear models examined relationships between cortical thickness and resting state functional connectivity (fc) with symptoms and functional status. In 373 Veterans, 98% were male with mean age 70.5± 8.3 years and FEV1% predicted 59 ± 21%. Compared to those with no co-occurrence of pain and dyspnea, those with co-occurrence walked 1,291-1,444 fewer steps per day and had an 80-85 m lower 6MWT distance. Ten males participated in the pilot neuroimaging study. Predominant findings were that lower cortical thickness and greater fc were associated with higher pain and dyspnea, p<0.05. Greater cortical thickness and lower fc were associated with higher daily step count and 6MWT distance, p<0.05. Regional patterns of associations differed for pain and dyspnea, suggesting that cortical thickness and fc may discriminate symptoms. Co-occurring dyspnea and pain in COPD are associated with significant reductions in PA and exercise capacity. It may be feasible for neuroimaging markers to discriminate between pain and dyspnea.

Apolipoprotein E (APOE) ε4 moderates the relationship between c-reactive protein, cognitive functioning, and white matter integrity

Elevated serum C-reactive protein (CRP) and possessing an APOE ε4 allele are two of the most prominent risk factors for cognitive and neurological dysfunction in older adults, but little is known about the unique or cumulative effects of these risk factors in young-to-middle-aged adults. To further characterize these potential relationships, measures of cognition and microstructural white matter integrity were examined using data from a sample of 329 post-9/11 war veterans that was collected as part of a comprehensive evaluation that included assessment of neuropsychological functioning, MRI scanning, psychiatric diagnoses, health screening, markers of inflammation, and APOE genotypes. Hierarchical linear regression analyses revealed the CRP and APOE ε4 interaction was associated with global cognition (β = -0.633), executive functioning (β = -0.566), and global fractional anisotropy (β = -0.470), such that elevated CRP was associated with worse cognition and white matter integrity in APOE ε4 carriers. Diffusion tensor imaging (DTI) was used to determine if CRP × APOE ε4 presence was associated with regionally specific fractional anisotropy in white matter tracts. Tract-based spatial statistics revealed CRP × APOE ε4 presence was associated with fractional anisotropy in the corpus callosum, right superior longitudinal fasciculus, right posterior corona radiata, as well as the bilateral anterior and superior corona radiatas. This suggests that APOE ε4 carriers may be uniquely vulnerable to the potentially negative impact of elevated systematic inflammation to cognition and microstructural white matter integrity.

Blast mild traumatic brain injury is associated with increased myopia and chronic convergence insufficiency

While chronic visual symptom complaints are common among Veterans with a history of mild traumatic brain injury (mTBI), research is still ongoing to characterize the pattern of visual deficits that is most strongly associated with mTBI and specifically, the impact of blast-related mTBI on visual functioning. One area that has not been well explored is the potential impact of blast mTBI on refractive error. While myopic shifts have been documented following head injuries in civilian populations, posttraumatic myopic shifts have not been explored in participants with military mTBI. This study investigated the impact of blast mTBIs on a range of visual function measures including distance acuity and refractive error, in a well-characterized cohort of thirty-one Post-9/11 veterans for whom detailed clinical interviews regarding military and TBI history were available. Seventeen participants had a history of blast-related mTBI (blast mTBI + group) while 14 did not (blast mTBI- group). Results show an increased frequency of convergence insufficiency and myopia in the blast mTBI + group relative to the blast mTBI- group. Linear regression analyses further show that deficits in distance acuity and refractive error are associated with the number of blast mTBIs during military service but not the number of non-blast mTBIs or the number of lifetime non-blast TBIs and cannot be accounted for by PTSD. These results are consistent with long-lasting damage following blast mTBI to subcortical visual structures that support both vergence movements and the accommodative functions needed to see clearly objects at varying distances.

Impaired executive function exacerbates neural markers of posttraumatic stress disorder

BACKGROUND

A major obstacle in understanding and treating posttraumatic stress disorder (PTSD) is its clinical and neurobiological heterogeneity. To address this barrier, the field has become increasingly interested in identifying subtypes of PTSD based on dysfunction in neural networks alongside cognitive impairments that may underlie the development and maintenance of symptoms. The current study aimed to determine if subtypes of PTSD, based on normative-based cognitive dysfunction across multiple domains, have unique neural network signatures.

METHODS

In a sample of 271 veterans (90% male) that completed both neuropsychological testing and resting-state fMRI, two complementary, whole-brain functional connectivity analyses explored the link between brain functioning, PTSD symptoms, and cognition.

RESULTS

At the network level, PTSD symptom severity was associated with reduced negative coupling between the limbic network (LN) and frontal-parietal control network (FPCN), driven specifically by the dorsolateral prefrontal cortex and amygdala Hubs of Dysfunction. Further, this relationship was uniquely moderated by executive function (EF). Specifically, those with PTSD and impaired EF had the strongest marker of LN-FPCN dysregulation, while those with above-average EF did not exhibit PTSD-related dysregulation of these networks.

CONCLUSION

These results suggest that poor executive functioning, alongside LN-FPCN dysregulation, may represent a neurocognitive subtype of PTSD.