Evaluation of objective and subjective clinical outcomes in combat veterans with and without mild TBI and PTSD: A four-group design

Research Letter: TBI Severity Moderates the Association Between Subjective and Objective Attention in Older Veterans

OBJECTIVE

This study examined the moderating effect of traumatic brain injury (TBI) history on subjective and objective cognition across multiple cognitive domains.

SETTING, PARTICIPANTS, AND DESIGN

Participants included 242 Vietnam-era veterans with a history of no TBI (n = 86), mild TBI (n = 74), or moderate-to-severe TBI (n = 82) from the observational Department of Defense-Alzheimer's Disease Neuroimaging Initiative (DoD-ADNI) study.

MAIN MEASURES

Objective cognition was the outcome and was measured using neuropsychological measures in the domains of memory, attention/executive functioning, and language. Subjective cognition was measured using the memory, divided attention, and language subscales from the Everyday Cognition (ECog) measure. TBI severity status was the moderating variable.

RESULTS

Veterans with a history of moderate-to-severe TBI had a stronger negative association between subjective and objective attention relative to participants without a TBI ( P = .002). Although this association did not differ between mild TBI and no TBI history groups ( P = .100), the association between subjective and objective attention for the mild TBI group was intermediate to the no TBI and moderate-to-severe TBI history groups. TBI status did not moderate associations between subjective and objective memory or language.

CONCLUSION

Results highlight the importance of assessing subjective and objective cognition in older veterans and the relevance of attention in the context of TBI history. More work is needed to better understand the intersection of TBI and aging and how these factors may be used to guide individualized assessment and treatment approaches for older veterans.

Exploring Interactions Between Traumatic Brain Injury History and Gender on Medical Comorbidities in Military Veterans: An Epidemiological Analysis in the VA Million Veteran Program

Epidemiological studies of medical comorbidities and possible gender differences associated with traumatic brain injury (TBI) are limited, especially among military veterans. The purpose of this study was to examine relationships between TBI history and a wide range of medical conditions in a large, national sample of veterans, and to explore interactions with gender. Participants of this cross-sectional epidemiological study included 491,604 veterans (9.9% TBI cases; 8.3% women) who enrolled in the VA Million Veteran Program (MVP). Outcomes of interest were medical comorbidities (i.e., neurological, mental health, circulatory, and other medical conditions) assessed using the MVP Baseline Survey, a self-report questionnaire. Logistic regression models adjusting for age and gender showed that veterans with TBI history consistently had significantly higher rates of medical comorbidities than controls, with the greatest differences observed across mental health (odds ratios [ORs] = 2.10-3.61) and neurological (ORs = 1.57-6.08) conditions. Similar patterns were found when evaluating men and women separately. Additionally, significant TBI-by-gender interactions were observed, particularly for mental health and neurological comorbidities, such that men with a history of TBI had greater odds of having several of these conditions than women with a history of TBI. These findings highlight the array of medical comorbidities experienced by veterans with a history of TBI, and illustrate that clinical outcomes differ for men and women with TBI history. Although these results are clinically informative, more research is needed to better understand the role of gender on health conditions in the context of TBI and how gender interacts with other social and cultural factors to influence clinical trajectories following TBI. Ultimately, understanding the biological, psychological, and social mechanisms underlying these comorbidities may help with tailoring TBI treatment by gender and improve quality of life for veterans with TBI history.

Chronic frontal neurobehavioural symptoms in combat-deployed military personnel with and without a history of blast-related mild traumatic brain injury

OBJECTIVE

This study evaluated frontal behavioural symptoms, via the FrSBe self-report, in military personnel with and without a history of blast-related mild traumatic brain injury (mild TBI).

METHODS

Prospective observational cohort study of combat-deployed service members leveraging 1-year and 5-year demographic and follow up clinical outcome data.

RESULTS

The blast mild TBI group (n = 164) showed greater frontal behavioural symptoms, including clinically elevated apathy, disinhibition, and executive dysfunction, during a 5-year follow-up, compared to a group of combat-deployed controls (n = 107) without mild TBI history or history of blast exposure. We also explored changes inbehaviourall symptoms over a 4-year span, which showed clinically significant increases in disinhibition in the blast mild TBI group, whereas the control group did not show significant increases in symptoms over time.

CONCLUSION

Our findings add to the growing evidence that a proportion of individuals who sustain mild TBI experience persistent behavioural symptoms. We also offer a demonstration of a novel use of the FrSBe as a tool for longitudinal symptom monitoring in a military mild TBI population.

Comparing resting-state connectivity of working memory networks in U.S. Service members with mild traumatic brain injury and posttraumatic stress disorder

Mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) are prevalent among military populations, and both have been associated with working memory (WM) impairments. Previous resting-state functional connectivity (rsFC) research conducted separately in PTSD and mTBI populations suggests that there may be similar and distinct abnormalities in WM-related networks. However, no studies have compared rsFC of WM brain regions in participants with mTBI versus PTSD. We used resting-state fMRI to investigate rsFC of WM networks in U.S. Service Members (n = 127; ages 18-59) with mTBI only (n = 46), PTSD only (n = 24), and an orthopedically injured (OI) control group (n = 57). We conducted voxelwise rsFC analyses with WM brain regions to test for differences in WM network connectivity in mTBI versus PTSD. Results revealed reduced rsFC between ventrolateral prefrontal cortex (vlPFC), lateral premotor cortex, and dorsolateral prefrontal cortex (dlPFC) WM regions and brain regions in the dorsal attention and somatomotor networks in both mTBI and PTSD groups versus controls. When compared to those with mTBI, individuals with PTSD had lower rsFC between both the lateral premotor WM seed region and middle occipital gyrus as well as between the dlPFC WM seed region and paracentral lobule. Interestingly, only vlPFC connectivity was significantly associated with WM performance across the samples. In conclusion, we found primarily overlapping patterns of reduced rsFC in WM brain regions in both mTBI and PTSD groups. Our finding of decreased vlPFC connectivity associated with WM is consistent with previous clinical and neuroimaging studies. Overall, these results provide support for shared neural substrates of WM in individuals with either mTBI or PTSD.

Disentangling subjective symptom complaints and objective cognitive performance in veterans: Impact of posttraumatic stress disorder and lifetime traumatic brain injury burden

Self-reported histories of mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) symptoms are prevalent among post-9/11 veterans. Both are associated with subjective and often overlapping symptom complaints, but variably with objective neuropsychological test performances. These outcomes are seldom explored in relation to lifetime mTBI burden. This cross-sectional study examined associations of PTSD and lifetime mTBI with subjective (persistent symptoms after concussion and cognitive complaints) and objective (performances across five cognitive domains) measures among 46 veterans. Within this sample, 20 veterans had Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) confirmed PTSD (PTSD+), whereas 26 demographically-similar participants did not meet criteria (PTSD-). The Boston Assessment of Traumatic Brain Injury-Lifetime (BAT-L) yielded total mTBI scores ranging from 0 to 8. Regressions showed PTSD was associated with increased subjective symptoms/cognitive complaints, along with reduced verbal fluency, visuospatial memory, and processing speed performances. Lifetime mTBI burden was associated with subjective symptoms, but not with objective cognitive test performance, after controlling for PTSD. No significant interactions were observed. Exploratory correlations suggested that all PTSD symptom clusters were generally associated with the subjective and objective measures. However, fewer significant associations emerged within the PTSD+/- groups separately, with each group yielding somewhat different patterns of relationships. PTSD and increasing mTBI burden are consistently associated with negative subjective symptoms, including cognitive complaints. Each condition likely explains some degree of unique variance in symptom reporting. PTSD is associated with poorer objective cognition on some tasks, including processing speed, executive functioning, and learning/memory. Implications are explored.

Low resilience following traumatic brain injury is strongly associated with poor neurobehavioral functioning in U.S. military service members and veterans

OBJECTIVE

The purpose of this study was to examine the relationship between resilience and self-reported neurobehavioral functioning following traumatic brain injury (TBI) in U.S. military service members and veterans (SMVs). A secondary objective was to examine the interaction between resilience and posttraumatic stress disorder (PTSD) on neurobehavioral functioning.

METHOD

Participants included 795 SMVs classified into four groups: Uncomplicated Mild TBI (MTBI; n=300); Complicated Mild, Moderate, Severe, or Penetrating TBI (STBI, n 162); Injured Controls (IC, n=185); and Non-injured Controls (NIC, n=148). Two independent cohorts were evaluated - those assessed within 1-year of injury and those assessed 10-years post-injury. SMVs completed self-report measures including the PTSD Checklist-Civilian version, Neurobehavioral Symptom Inventory, and TBI-Quality of Life.

RESULTS

Results showed that (1) lower resilience was strongly associated with poorer neurobehavioral functioning across all groups at 1-year and 10-years post-injury, and (2) PTSD and resilience had a robust influence on neurobehavioral functioning at both time periods post-injury, such that SMVs with PTSD and low resilience displayed the poorest neurobehavioral functioning.

CONCLUSION

Results suggest that regardless of injury group and time since injury, resilience and PTSD strongly influence neurobehavioral functioning following TBI among SMVs. Future research evaluating interventions designed to enhance resilience in this population is indicated.

Clinical research findings from the long-term impact of military-relevant brain injury consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) 2013-2021

This is a summary of the published research from the 14 observational, longitudinal and big-data, epidemiological studies supported by the LIMBIC-CENC program from 2013-2021 examining the long-term effects of combat-related traumatic brain injury (TBI). Findings from these 43 primary and secondary analyses include: 1) unique fluid, advanced neuroimaging and electrophysiologic biomarkers associated with mild traumatic brain injury (mTBI), number of mTBIs and related dysfunction, 2) increases in a range of chronic difficulties, including neurosensory, sleep, pain, cognitive deficits, behavioral disorders, overall symptom burden, healthcare costs and service-connected disability, associated with mTBI, all-severity traumatic brain injury (TBI), blast exposure, and number of mTBIs, and 3) increases in the risk for suicide and neurodegeneration, including dementia and Parkinson's disease, associated with mTBI and all-severity TBI. Ongoing LIMBIC-CENC longitudinal and epidemiologic research will clarify, confirm and expand upon these findings.

Characterization of Million Veteran Program (MVP) enrollees with Comprehensive Traumatic Brain Injury Evaluation (CTBIE) data: An analysis of neurobehavioral symptoms

The purpose of this study was to examine neurobehavioral symptom reporting in a large sample of military veterans (N = 12,144) who completed the Comprehensive Traumatic Brain Injury Evaluation (CTBIE) and enrolled in the VA's Million Veteran Program (MVP). The CTBIE is a clinician-administered interview that assesses for historical, deployment-related traumatic brain injury (TBI) and evaluates symptoms using the Neurobehavioral Symptom Inventory (NSI). Clinicians completing the CTBIE made clinical determinations about participants' (1) TBI diagnostic status (i.e., CTBIE+ or CTBIE-) and (2) current symptom etiology (i.e., Symptom Resolution, TBI, Behavioral Health, Comorbid TBI + Behavioral Health [Comorbid], or Other). We evaluated the association of TBI diagnostic status and symptom etiology group with neurobehavioral symptoms. Results showed a significant association between TBI diagnostic status and all NSI variables, with CTBIE+ veterans endorsing greater symptoms than CTBIE- veterans. There was also a significant association between symptom etiology group and all NSI variables; specifically, the Comorbid and Behavioral Health groups generally endorsed significantly greater symptoms compared to the other groups. Follow-up analyses showed that relative to the Symptom Resolution group, the Comorbid and Behavioral Health groups had increased odds of severe/very severe cognitive and affective symptoms, whereas the TBI and Other groups did not. Finally, presence of psychiatric symptoms, pain, post-traumatic amnesia, loss of consciousness, and blast exposure significantly predicted Comorbid symptom etiology group membership. Findings from this large epidemiologic MVP study have relevant clinical implications and further highlight the importance of prioritizing integrated behavioral health interventions for this vulnerable population.

Research Letter: PTSD Symptom Severity and Multiple Traumatic Brain Injuries Are Associated With Elevated Memory Complaints in Veterans With Histories of Mild TBI

OBJECTIVE

The evaluation of memory complaints in mild traumatic brain injury (mTBI) remains an important clinical consideration, especially in the context of comorbid psychiatric symptoms such as posttraumatic stress disorder (PTSD). We compared subjective memory complaints in veterans with and without a history of mTBI, examined ratings between those with single versus multiple mTBIs, and investigated associations between memory complaints and PTSD symptom severity.

METHODS

117 outpatient veterans (mTBI: n = 79 [single mTBI: n = 22, multiple mTBI: n = 57], military controls [MCs]: n = 38) completed a TBI history assessment, the Prospective-Retrospective Memory Questionnaire (PRMQ), and the PTSD Checklist-Military Version (PCL-M).

RESULTS

Hierarchical multiple regression showed that greater PCL-M scores significantly predicted elevated PRMQ-Total scores, accounting for 38% of the variance explained (P < .001). mTBI status predicted an additional 5% of variance in memory complaints (P < .01). The multiple-mTBI group endorsed more memory complaints than either MCs (P < .01) or the single-mTBI group (P < .05), who did not differ from MCs (P > .50).

CONCLUSIONS

Comorbid PTSD symptoms are an important factor when considering memory complaints in veterans with a reported history of mTBI. However, independent of comorbid PTSD symptoms, mTBI status-particularly in the context of repetitive neurotrauma-uniquely contributes to memory complaints. Findings suggest that veterans with a history of multiple mTBIs may be a particularly vulnerable group in need of specialized interventions and/or psychoeducation.

Path Analysis of the Mediating Roles of Personality, Distress, and Cognitive Flexibility in the Subjective Well-Being of Combat Veterans With Traumatic Brain Injury

OBJECTIVE

To determine the interrelationships among traumatic brain injury (TBI), maladaptive personality traits (MPT), psychological distress, and cognitive flexibility in the prediction of subjective well-being of post-9/11 veterans concurrently and over time.

SETTING

Five Veterans Affairs (VA) medical centers and 1 VA outpatient clinic in urban, suburban, and rural areas.

PARTICIPANTS

Five hundred Operation Enduring Freedom/Operation Iraqi Freedom veterans at baseline (219 with TBI), 292 at 18-month follow-up (108 with TBI), drawn from a regional registry and clinic referrals.

DESIGN

Path analysis of data from a prospective cohort study.

MAIN MEASURES

Satisfaction with Life Scale, 36-ltem Short-Form Health Survey (SF-36) Health Scale, Personality Assessment Screener, Beck Depression Inventory-II, Beck Anxiety Inventory, Posttraumatic Stress Disorder Checklist-Military, Trail Making Test, Part B, Delis-Kaplan Executive Function System (D-KEFS) Category-Switching Verbal Fluency, and D-KEFS Color-Word Interference Test.

RESULTS

There was no direct effect of TBI on well-being at baseline or 18 months later. Psychological distress, MPT, and cognitive flexibility had significant direct effects on well-being at baseline and 18 months. Baseline model accounted for 66% of the variance in well-being; follow-up model accounted for 43% of well-being variance. Negative influence of distress significantly decreased from baseline to follow-up. Direct negative effect of MPT diminished slightly over 18 months; effect of cognitive flexibility increased. Significant relationships were estimated in prediction of distress by MPT, cognitive flexibility, and TBI. TBI predicted MPT. MPT, cognitive flexibility, and TBI had indirect effects on well-being. TBI had a positive indirect influence on distress. Total effects included 4 significant predictors of well-being at baseline and 18 months: distress, MPT, cognitive flexibility, and TBI.

CONCLUSION

Experience of TBI alone did not predict subjective well-being at baseline or 18 months later. Psychological distress, MPT, and cognitive flexibility had direct effects on well-being at both time points. Interventions aimed at reducing distress and bolstering resilience and cognitive flexibility are recommended to increase subjective well-being in this population.

Psychoeducation as Precision Health in Military-Related Mild Traumatic Brain Injury

A significant proportion of Service Members and Veterans (SMVs) experience at least 1 mild traumatic brain injury during military activities (mil-mTBI), which can result in enduring cognitive symptoms. Although multiple cognitive rehabilitation (CR) interventions have been developed for this population, patient psychoeducation focusing on biopsychosocial relationships and health behaviors is often cited as the first line of defense for mil-mTBI sequelae. However, theoretical and conceptual foundations of these psychoeducational techniques are not well articulated. This raises questions about the potency of attempts to boost health literacy in affected SMVs, who represent a highly heterogeneous patient population within a special cultural milieu. To elucidate the significance of this problem and identify opportunities for improvement, we view the psychoeducation of SMVs through the lens of educational principles described in serious mental illness, where "psychoeducation" was first formally defined, as well as contextual and phenomenological aspects of mil-mTBI that may complicate treatment efforts. To advance psychoeducation research and practice in mil-mTBI, we discuss how treatment theory, which seeks to link active treatment ingredients with specific therapeutic targets, and an associated conceptual framework for medical rehabilitation-the Rehabilitation Treatment Specification System-can be leveraged to personalize educational content, integrate it into multicomponent CR interventions, and evaluate its effectiveness.

Self-efficacy and coping style in Iraq and Afghanistan-era veterans with and without mild traumatic brain injury and posttraumatic stress disorder

OBJECTIVE

To examine self-efficacy and coping style in combat-exposed Veterans with and without mild traumatic brain injury (mTBI) history and posttraumatic stress disorder (PTSD).

METHODS

Veterans (N = 81) were categorized into four groups: comorbid mTBI and PTSD (n = 23), PTSD-only (n = 16), mTBI-only (n = 25), and combat-exposed controls (n = 17). Outcomes included the Self-Efficacy for Symptom Management Scale and the Brief Coping Orientation to Problems Experienced.

RESULTS

Significant group effects were found on self-efficacy and coping style, even when adjusting for total mTBIs and psychiatric comorbidities. Post-hoc analyses revealed that the comorbid and PTSD-only groups generally had lower self-efficacy than the mTBI-only and control groups and that the PTSD-only group used less action-focused coping than the mTBI-only and control groups.

CONCLUSION

Our results suggest that self-efficacy and coping style vary as a function of mTBI history and PTSD status and that it may be important to integrate these malleable factors into interventions for this population.

Facilitating Successful Reentry Among Justice-involved Veterans: The Role of Veteran and Offender Identity

Reentry courts facilitate successful offender reintegration into the community following release from incarceration, and many justice-involved veterans may benefit from such services given their elevated risk for deleterious outcomes postrelease. However, effectively engaging court participants is a crucial foundation to achieve the goals of recidivism reduction and global psychosocial improvement. This conceptual article presents an overview of factors that may interfere with a veteran's engagement in reentry court through the lens of both veteran and offender identity. Recommendations for reentry court personnel based on justice-involved veterans' experiences, identity, and unique needs are presented. Careful consideration of these factors and associated practice adaptations may facilitate rapport between reentry court personnel and veteran participants, foster engagement, and ultimately improve outcomes among this unique, at-risk population.

Post-concussive symptom endorsement and symptom attribution following remote mild traumatic brain injury in combat-exposed Veterans: An exploratory study

The purpose of this study was to examine rates of and relationships between "post-concussive" symptom endorsement and symptom attribution in Veterans with a history of mild traumatic brain injury (mTBI). This cross-sectional, exploratory study included 48 combat-exposed Iraq/Afghanistan Veterans with remote history of mTBI. All Veterans completed clinical interviews and self-report questionnaires assessing sociodemographic factors, injury and combat-related variables, psychiatric distress, self-efficacy, and coping style. To assess symptom endorsement and symptom attribution, a modified version of the Neurobehavioral Symptom Inventory was administered. Results showed that the most commonly endorsed "post-concussive" symptoms were several non-specific symptoms, while the symptoms most frequently attributed to mTBI included forgetfulness, poor concentration, and headaches. Furthermore, although there were some overlapping correlates of both symptom endorsement and symptom attribution, unique variables were associated with each domain. Specifically, symptom endorsement was uniquely associated with measures of psychiatric distress, while symptom attribution was uniquely associated with having a history of loss of consciousness and a greater degree of combat exposure. Taken together, results suggest that endorsement of symptoms may be significantly impacted by the presence of mental health comorbidities, but that perceptions or beliefs as to why symptoms are occurring are related more to mTBI and combat-related characteristics. Findings offer potential avenues for therapeutic intervention, emphasize the importance of psychoeducation, and highlight the need to consider using alternate terminology for these symptoms that promotes recovery and minimizes misattribution of symptoms.

Factors associated with employment and work perception in combat-exposed veterans

PURPOSE/OBJECTIVE

The purpose of this study was 2-fold: (a) to evaluate whether perception of work ability is associated with employment status in a sample of combat-exposed veterans, and (b) to determine whether the same sets of variables that are associated with employment status are also associated with perception of work ability. Research Method/Design: In this cross-sectional study, veterans (N = 83) underwent a neuropsychological assessment and completed questionnaires assessing demographic characteristics, combat-related experiences, and psychiatric and neurobehavioral/health-related symptoms. Primary outcomes of interest were employment status (unemployed vs. employed) and veterans' perception of whether their ability to work has declined due to an ongoing condition (yes vs. no).

RESULTS

A chi-square analysis revealed a significant relationship between perception of work ability and employment status. Additionally, psychiatric and neurobehavioral/health-related symptoms were associated with employment status and perception of work ability, whereas demographic characteristics (i.e., service-connected disability rating) and combat-related experiences (i.e., mTBI history) were only associated with perception of work ability. Objective cognitive functioning was not associated with employment status or perception of work ability.

CONCLUSIONS/IMPLICATIONS

Although preliminary, results suggest that perception of work ability is an important factor to consider when evaluating employment-related outcomes in veterans. Moreover, results indicate that while there is some overlap among the variables associated with employment status and perception of work ability, additional variables are linked with perception of work ability. Taken together, these findings suggest that perception of one's ability to work and factors that influence it may be particularly important treatment targets in the veteran population. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Psychological predictors of functional outcomes in service members with traumatic brain injury

PRIMARY OBJECTIVE

Research is increasingly demonstrating the significant impact that non-medical factors can have on outcomes of service members (SMs) with mild traumatic brain injury (mTBI). Thus, the current study examined which demographic, TBI-related factors, and psychological variables are most predictive of functional outcomes.

RESEARCH DESIGN

Retrospective database analysis from medical chart review.

METHODS AND PROCEDURES

One hundred forty-one patients who received rehabilitation services at an outpatient TBI military treatment facility between 2013 and 2018. Data collected included demographic variables, time since injury, neuropsychological measures, psychological diagnoses, Personality Assessment Inventory (PAI) scores, and Walter Reed Functional Impairment Scale (FIS). Hierarchical linear regression models were used to predict functional outcomes (measured by FIS total, work, social functioning scales).

MAIN OUTCOMES AND RESULTS

Results indicated that comorbid PTSD diagnosis and PAI Negative Impression Management (NIM) score were predictive of total functional, work, and social outcomes, over and above demographic and TBI-related factors.

CONCLUSIONS

Current findings confirmed the importance of evaluating and treating psychological factors, as well as exploring one's responding style (NIM), when managing chronic mTBI in SMs. Given ongoing findings of psychological underpinnings to mTBI outcome, there is further need to focus on early interventions to optimize psychological and functional outcomes for SMs.

PTSD, but not history of mTBI, is associated with altered myelin in combat-exposed Iraq and Afghanistan Veterans

OBJECTIVE

To investigate the biological, cognitive, and psychological presentations of combat-exposed Veterans with a history of mild traumatic brain injury (mTBI) and/or posttraumatic stress disorder (PTSD) using a novel white matter imaging technique and comprehensive neuropsychological assessment.

METHOD

74 Iraq and Afghanistan Veterans (mean age 33.89, 90.5% male) with history of mTBI (average 7.25 years since injury), PTSD, both, or neither underwent magnetic resonance imaging (MRI) exams including acquisition of a novel imaging technique, multicomponent-driven equilibrium single-pulse observation of T1/T2 (mcDESPOT) to quantify myelin water fraction (MWF), a surrogate measure of myelin content. Participants also underwent comprehensive neuropsychological assessment and three cognitive composite scores (memory, working memory/processing speed, and executive functioning) were created.

RESULTS

There were no significant group differences on the neuropsychological composite scores. ANCOVAs revealed a main effect of PTSD across all a priori regions of interest (ROI) in which PTSD was associated with higher MWF. There was no main effect of mTBI history or TBI by PTSD interaction on any ROI. Significant positive associations were observed between myelin and PTSD symptoms, but no significant associations were found between myelin and neurobehavioral symptoms. No significant associations were found between myelin in the a priori ROIs and the cognitive composite scores.

CONCLUSION

This study did not find neuropsychological or MWF differences in combat Veterans with a remote history of mTBI but did find myelin alterations related to PTSD. Psychological trauma should be a primary target for intervention in Veterans with comorbid PTSD and mTBI reporting subjective complaints, given its salience.