An Update on the Complexity and Importance of Accurately Diagnosing Post-Traumatic Stress Disorder and Comorbid Traumatic Brain Injury

ZL006 mitigates anxiety-like behaviors induced by closed head injury through modulation of the neural circuit from the medial prefrontal cortex to amygdala

Closed head injury is a prevalent form of traumatic brain injury with poorly understood effects on cortical neural circuits. Given the emotional and behavioral impairments linked to closed head injury, it is vital to uncover brain functional deficits and their driving mechanisms. In this study, we employed a robust viral tracing technique to identify the alteration of the neural pathway connecting the medial prefrontal cortex to the basolateral amygdala, and we observed the disruptions in neuronal projections between the medial prefrontal cortex and the basolateral amygdala following closed head injury. Remarkably, our results highlight that ZL006, an inhibitor targeting PSD-95/nNOS interaction, stands out for its ability to selectively reverse these aberrations. Specifically, ZL006 effectively mitigates the disruptions in neuronal projections from the medial prefrontal cortex to basolateral amygdala induced by closed head injury. Furthermore, using chemogenetic approaches, we elucidate that activating the medial prefrontal cortex projections to the basolateral amygdala circuit produces anxiolytic effects, aligning with the therapeutic potential of ZL006. Additionally, ZL006 administration effectively mitigates astrocyte activation, leading to the restoration of medial prefrontal cortex glutamatergic neuron activity. Moreover, in the context of attenuating anxiety-like behaviors through ZL006 treatment, we observe a reduction in closed head injury-induced astrocyte engulfment, which may correlate with the observed decrease in dendritic spine density of medial prefrontal cortex glutamatergic neurons.

mTBI evaluation, management, and referral to allied healthcare: practices of first-line healthcare professionals

PRIMARY OBJECTIVE

To gain an understanding of current evaluation practices, post-injury recommendations, and referrals to allied healthcare professions (AHP) by first-line healthcare professionals (FHPs) providing care for people with mild traumatic brain injury (mTBI).

RESEARCH DESIGN

Survey study.

METHODS AND PROCEDURES

Physicians, physician assistants, nurse practitioners, nurses, and athletic trainers (n = 126) completed an online survey, including Likert scale and free response question relating to mTBI evaluation, management, and referral practices.

MAIN OUTCOMES AND RESULTS

FHPs surveyed reported being confident in their ability to evaluate patients with suspected mTBI, relying most heavily on patient-reported symptoms and physical signs as methods of evaluation. Most FHPs reported making recommendations to compensate for the symptoms experienced following mTBI diagnosis. In contrast, FHPs expressed challenges in the evaluation and management of symptoms associated with mTBI along with limited knowledge of and referrals to AHPs.

CONCLUSIONS

Overall, FHPs feel confident in the diagnosis of mTBI but experience assessment and management challenges. AHPs are underutilized on mTBI management teams calling for a need for multidisciplinary collaboration on research, education, and rehabilitation efforts to optimally care for people experiencing mTBI symptoms.

The neural circuits and molecular mechanisms underlying fear dysregulation in posttraumatic stress disorder

Post-traumatic stress disorder (PTSD) is a stress-associated complex and debilitating psychiatric disorder due to an imbalance of neurotransmitters in response to traumatic events or fear. PTSD is characterized by re-experiencing, avoidance behavior, hyperarousal, negative emotions, insomnia, personality changes, and memory problems following exposure to severe trauma. However, the biological mechanisms and symptomatology underlying this disorder are still largely unknown or poorly understood. Considerable evidence shows that PTSD results from a dysfunction in highly conserved brain systems involved in regulating stress, anxiety, fear, and reward circuitry. This review provides a contemporary update about PTSD, including new data from the clinical and preclinical literature on stress, PTSD, and fear memory consolidation and extinction processes. First, we present an overview of well-established laboratory models of PTSD and discuss their clinical translational value for finding various treatments for PTSD. We then highlight the research progress on the neural circuits of fear and extinction-related behavior, including the prefrontal cortex, hippocampus, and amygdala. We further describe different molecular mechanisms, including GABAergic, glutamatergic, cholinergic, and neurotropic signaling, responsible for the structural and functional changes during fear acquisition and fear extinction processes in PTSD.

Differences in Symptom Report by Survivors With and Without Probable Intimate Partner Violence-Related Brain Injury

Survivors of intimate partner violence (IPV) are at heightened risk of sustaining a brain injury (BI). Problematically, a high overlap between BI and trauma symptoms leads to difficulties in identifying when an IPV-related BI has occurred. This paper investigated differences in symptom reports between survivors with (n = 95) and without (n = 42) probable IPV-related BI. Chi-squared analyses isolated a constellation of symptoms found to be specifically associated with BI status. These symptomatic markers may assist professionals in discerning BI from other comorbid conditions present in IPV, and thus help survivors access BI-specific treatments and resources.

Levels of Arachidonic Acid-Derived Oxylipins and Anandamide Are Elevated Among Military APOE ɛ4 Carriers With a History of Mild Traumatic Brain Injury and Post-Traumatic Stress Disorder Symptoms

Currently approved blood biomarkers detect intracranial lesions in adult patients with mild to moderate traumatic brain injury (TBI) acutely post-injury. However, blood biomarkers are still needed to help with a differential diagnosis of mild TBI (mTBI) and post-traumatic stress disorder (PTSD) at chronic post-injury time points. Owing to the association between phospholipid (PL) dysfunction and chronic consequences of TBI, we hypothesized that examining bioactive PL metabolites (oxylipins and ethanolamides) would help identify long-term lipid changes associated with mTBI and PTSD. Lipid extracts of plasma from active-duty soldiers deployed to the Iraq/Afghanistan wars (control = 52, mTBI = 21, PTSD = 34, and TBI + PTSD = 13) were subjected to liquid chromatography/mass spectrometry analysis to examine oxylipins and ethanolamides. Linear regression analyses followed by post hoc comparisons were performed to assess the association of these lipids with diagnostic classifications. Significant differences were found in oxylipins derived from arachidonic acid (AA) between controls and mTBI, PTSD, and mTBI + PTSD groups. Levels of AA-derived oxylipins through the cytochrome P450 pathways and anandamide were significantly elevated among mTBI + PTSD patients who were carriers of the apolipoprotein E E4 allele. These studies demonstrate that AA-derived oxylipins and anandamide may be unique blood biomarkers of PTSD and mTBI + PTSD. Further, these AA metabolites may be indicative of an underlying inflammatory process that warrants further investigation. Future validation studies in larger cohorts are required to determine a potential application of this approach in providing a differential diagnosis of mTBI and PTSD in a clinical setting.

Disturbances in fear extinction learning after mild traumatic brain injury in mice are accompanied by alterations in dendritic plasticity in the medial prefrontal cortex and basolateral nucleus of the amygdala

Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) have emerged as the signature injuries of the U.S. veterans who served in Iraq and Afghanistan, and frequently co-occur in both military and civilian and populations. To better understand how fear learning and underlying neural systems might be altered after mTBI we examined the acquisition of cued fear conditioning and its extinction along with brain morphology and dendritic plasticity in a mouse model of mTBI. To induce mTBI in adult male C57BL/6J mice, a lateral fluid percussive injury (LFP 1.7) was produced using a fluid pulse of 1.7 atmosphere force to the right parietal lobe. Behavior in LFP 1.7 mice was compared to behavior in mice from two separate control groups: mice subjected to craniotomy without LFP injury (Sham) and mice that did not undergo surgery (Unoperated). Following behavioral testing, neural endpoints (dendritic structural plasticity and neuronal volume) were assessed in the basolateral nucleus of the amygdala (BLA), which plays a critical sensory role in fear learning, and medial prefrontal cortex (mPFC), responsible for executive functions and inhibition of fear behaviors. No gross motor abnormalities or increased anxiety-like behaviors were observed in LFP or Sham mice after surgery compared to Unoperated mice. We found that all mice acquired fear behavior, assessed as conditioned freezing to auditory cue in a single session of 6 trials, and acquisition was similar across treatment groups. Using a linear mixed effects analysis, we showed that fear behavior decreased overall over 6 days of extinction training with no effect of treatment group across extinction days. However, a significant interaction was demonstrated between the treatment groups during within-session freezing behavior (5 trials per day) during extinction training. Specifically, freezing behavior increased across within-session extinction trials in LFP 1.7 mice, whereas freezing behavior in control groups did not change on extinction test days, reflecting a dissociation between within-trial and between-trial fear extinction. Additionally, LFP mice demonstrated bilateral increases in dendritic spine density in the BLA and decreases in dendritic complexity in the PFC. The translational implications are that individuals with TBI undergoing fear extinction therapy may demonstrate within-session aberrant learning that could be targeted for more effective treatment interventions.

Self-injurious thoughts and behaviors in Russian patients with epilepsy: A prospective observational study

OBJECTIVE

A two-stage study aimed to estimate the prevalence of different types of self-injurious behaviors (suicidal ideation (SI), suicide attempts (SA), and nonsuicidal self-injury (NSSI)) in Russian patients with epilepsy (PWE), to identify factors associated with such behaviors, and to assess their impact on 3-year mortality.

METHODS

We enrolled 459 consecutive adult PWE from two level 2 outpatient epilepsy centers in Moscow. The study consisted of two phases - first, we assessed all demographic and clinical characteristics and patients' history of SI, SA, and NSSI. In the second phase, three years after the initial screening, we analyzed patients' medical records to assess how self-injurious thoughts and behaviors were related to actual mortality.

RESULTS

In our sample, the total lifetime and 12-month prevalence of SI was 20% and 5.7%, of SA was 8.3% and 0.7%, and of NSSI was 15.3% and 2.8%, respectively. We found no differences between deceased and alive PWE regarding lifetime and 12-month prevalence of SI, SA, and NSSI. Higher seizure frequency, lifetime NSSI and lifetime diagnosis of mental disorder were associated with SI, whereas traumatic brain injury (TBI), substance abuse, and NSSI were associated with SA in PWE.

SIGNIFICANCE

Our study adds to the existing data on the prevalence of different types of suicidal behaviors in PWE and advances research on NSSI in this population. However, more research is needed on the long-term consequences of different types of self-injurious behaviors.

Exploring the intersection of brain injury and mental health in survivors of intimate partner violence: A scoping review

Rationale

Intimate partner violence (IPV) is the most commonly occurring form of violence against women. The most common site of injury in IPV is the head, face, and neck, resulting in possible brain injury (BI). Independently, mental health (MH) concerns are highly prevalent among both IPV survivors and individuals with BI; however, no systematic review exists on the combined experience of BI and MH in IPV.

Objective

The aim of this review was to describe the identification of and relationships between BI, MH, and IPV in the literature and the implications for health policy and practice.

Methods

A search strategy including text words and subject headings related to BI, IPV, and MH was developed for MEDLINE and translated to EMBASE, PsycINFO, CINAHL, Cochrane, Scopus, and Web of Science. Two reviewers independently assessed articles for inclusion. Articles discussing MH, BI, and IPV in relation to one another were included in the review.

Results

Twenty-eight articles were identified for inclusion. Methods for identifying IPV, BI, and MH were highly variable across studies. Fourteen studies reported significantly higher MH scores in IPV survivors with BI than in those without BI. Articles predominantly focused on cis gender women in heterosexual relationships and the impact of race and ethnicity were largely overlooked. Healthcare access was explored by eight articles, though none discussed the implications of co-occurring BI and MH.

Conclusion

Brain injury and MH are highly prevalent among IPV survivors; however, little research discusses the implication for healthcare. Future research should explore healthcare-related needs and experiences to inform policy and practice and better represent the diversity of IPV survivors.

Prevalence and correlates of self-reported cognitive difficulties in deployment-injured U.S. military personnel

Cognitive difficulties typically resolve within days to weeks following mild traumatic brain injury (mTBI); however, a sizable proportion of individuals continue to report cognitive symptoms months to years later that are often associated with posttraumatic stress disorder (PTSD) and depression to a greater degree than a history of mTBI. The current study sought to evaluate the prevalence of self-reported cognitive difficulties as well as the relative contributions of demographic, injury-related, and mental health variables in a large study of U.S. military personnel injured during deployment since 2001. Slightly fewer than half (42.0%) of participants reported elevated cognitive difficulties compared with a normative population; however, this was driven primarily by those who screened positive for PTSD or depression. Hierarchical linear regression revealed that various demographic and injury factors, including lower educational attainment, retired or separated military status, enlisted rank, and a history of deployment-related mTBI, were associated with more self-reported cognitive difficulties, f² = 0.07. Screening positive for PTSD or depression accounted for 32.1% of the variance in self-reported cognitive symptoms, f² = 0.63, whereas injury variables, including a history of deployment-related mTBI, albeit significant in the model, accounted for 1.6%. The current findings add to the growing body of literature underscoring the importance of screening for and treating mental health conditions in injured military personnel.

Executive functioning deficits exacerbate posttraumatic stress symptoms: A longitudinal mediation model

Executive functioning (EF) consists of a set of related, but distinct, higher-level cognitive abilities that are used to organize and integrate lower-level processes in the service of engaging in goal-direct behavior. Evidence suggests that deficits in EF are a vulnerability factor for the development of posttraumatic stress (PTS) symptoms. Less understood, however, is the role that EF plays in symptom maintenance and exacerbation following trauma exposure. As such, the primary purpose of the present study was to determine whether EF deficits exacerbate PTS symptoms over the course of one year. A secondary aim of this study was to use a cross-lagged design to determine the directional relations among EF deficits and PTS. Trauma-exposed adults (N = 98) completed a clinical interview and self-report measures at an initial assessment session (Time 1 [T1]). Participants also completed self-report measures at 6- (Time 2 [T2]; n = 92) and 12-month (Time 3 [T3]; n = 91) follow-up sessions. As predicted, EF deficits at T2 mediated the relationship between PTS symptoms from T1 to T3, thus suggesting that EF deficits exacerbate PTS symptoms following trauma exposure. Results from a cross-lagged path analysis from T2 to T3 suggest that deficits in EF exert a stronger influence on the maintenance of PTS symptoms than vice versa. These results have implications for (a) identifying individuals that are at elevated risk for developing PTS symptoms, (b) developing precision medicine-based approaches for alleviating PTS symptoms, and (c) improving well-established PTSD treatments for those with relative deficits in EF.

A systematic review on integrated care for traumatic brain injury, mental health, and substance use

Traumatic brain injuries (TBI) and mental health or substance use disorders (MHSU) are global public health concerns due to their prevalence and impact on individuals and societies. However, care for individuals with TBI and MHSU remains fragmented with a lack of appropriate services and supports across the continuum of healthcare. This systematic review provided an evidence-based foundation to inform opportunities to mobilize and adapt existing resources to integrate care for individuals with TBI and MHSU by comprehensively summarizing existing integrated activities and reported barriers and facilitators to care integration. MEDLINE, EMBASE, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials, Sociological Abstracts, and Dissertations & Theses Global were independently reviewed by two reviewers based on pre-determined eligibility criteria. Data on the integration activity, level and type of integration, reported barriers and facilitators, and the strategies aligning with the World Health Organization’s (WHO) Framework on Integrated Person-Centred Care were extracted to form the basis for a narrative synthesis. Fifty-nine peer-reviewed articles were included, describing treatments (N = 49), programs (N = 4), or screening activities (N = 7). Studies discussing clinical integration at the micro- (N = 38) and meso- (N = 10) levels, service integration at the micro- (N = 6) and meso- (N = 5) levels, and functional integration at the meso-level (N = 1) were identified. A minority of articles reported on facilitators (e.g., cognitive accommodations in treatment plans; N = 7), barriers (e.g., lack of education on cognitive challenges associated with TBI; N = 2), or both (N = 6), related to integrating care. This review demonstrated that integrated TBI and MHSU care already exists across a range of levels and types. Given the finite and competing demands for healthcare resources, cognitive accommodations across treatment plans to facilitate integrated TBI and MHSU care should be considered. Multidisciplinary teams should also be explored to provide opportunities for education among health professionals so they can be familiar with TBI and MHSU.

Trial registration: Prospero Registration: CRD42018108343.

Therapeutic potential of nociceptin/orphanin FQ peptide (NOP) receptor modulators for treatment of traumatic brain injury, traumatic stress, and their co-morbidities

The nociceptin/orphanin FQ (N/OFQ) peptide (NOP) receptor is a member of the opioid receptor superfamily with N/OFQ as its endogenous agonist. Wide expression of the NOP receptor and N/OFQ, both centrally and peripherally, and their ability to modulate several biological functions has led to development of NOP receptor modulators by pharmaceutical companies as therapeutics, based upon their efficacy in preclinical models of pain, anxiety, depression, Parkinson's disease, and substance abuse. Both posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI) are debilitating conditions that significantly affect the quality of life of millions of people around the world. PTSD is often a consequence of TBI, and, especially for those deployed to, working and/or living in a war zone or are first responders, they are comorbid. PTSD and TBI share common symptoms, and negatively influence outcomes as comorbidities of the other. Unfortunately, a lack of effective therapies or therapeutic agents limits the long term quality of life for either TBI or PTSD patients. Ours, and other groups, demonstrated that PTSD and TBI preclinical models elicit changes in the N/OFQ-NOP receptor system, and that administration of NOP receptor ligands alleviated some of the neurobiological and behavioral changes induced by brain injury and/or traumatic stress exposure. Here we review the past and most recent progress on understanding the role of the N/OFQ-NOP receptor system in PTSD and TBI neurological and behavioral sequelae. There is still more to understand about this neuropeptide system in both PTSD and TBI, but current findings warrant further examination of the potential utility of NOP modulators as therapeutics for these disorders and their co-morbidities. We advocate the development of standards for common data elements (CDE) reporting for preclinical PTSD studies, similar to current preclinical TBI CDEs. That would provide for more standardized data collection and reporting to improve reproducibility, interpretation and data sharing across studies.

Role of Inflammation in Traumatic Brain Injury-Associated Risk for Neuropsychiatric Disorders: State of the Evidence and Where Do We Go From Here

In the past decade, there has been an increasing awareness that traumatic brain injury (TBI) and concussion substantially increase the risk for developing psychiatric disorders. Even mild TBI increases the risk for depression and anxiety disorders such as posttraumatic stress disorder by two- to threefold, predisposing patients to further functional impairment. This strong epidemiological link supports examination of potential mechanisms driving neuropsychiatric symptom development after TBI. One potential mechanism for increased neuropsychiatric symptoms after TBI is via inflammatory processes, as central nervous system inflammation can last years after initial injury. There is emerging preliminary evidence that TBI patients with posttraumatic stress disorder or depression exhibit increased central and peripheral inflammatory markers compared with TBI patients without these comorbidities. Growing evidence has demonstrated that immune signaling in animals plays an integral role in depressive- and anxiety-like behaviors after severe stress or brain injury. In this review, we will 1) discuss current evidence for chronic inflammation after TBI in the development of neuropsychiatric symptoms, 2) highlight potential microglial activation and cytokine signaling contributions, and 3) discuss potential promise and pitfalls for immune-targeted interventions and biomarker strategies to identify and treat TBI patients with immune-related neuropsychiatric symptoms.

Application of neuropsychology and imaging to brain injury and use of the integrative cognitive rehabilitation psychotherapy model

BACKGROUND

An early approach to cognitive rehabilitation therapy (CRT) was developed based on A. R. Luria's theory of brain function. Expanding upon this approach, the Integrative Cognitive Rehabilitation Psychotherapy model (ICRP) was advanced.

OBJECTIVE

To describe the ICRP approach to treatment of clients post brain injury and provide a comprehensive list of evaluation tools to determine the client's abilities and needs. Finally, to provide a link between CRT and functional imaging studies designed to improve rehabilitation efforts.

METHODS

History of cognitive rehabilitation and neuropsychological testing is reviewed and description of cognitive, academic, psychiatric, and substance abuse tools are provided. Cognitive and emotional treatment techniques are fully described. Additionally, a method of determining the client's stage of recovery and pertinent functional imaging studies is detailed.

RESULTS

Authors have been able to provide a set of tools and techniques to use in comprehensive treatment of clients with brain injury.

CONCLUSIONS

Inclusive treatment which is outlined in the ICRP model is optimal for the client's recovery and return to a full and satisfying life post brain injury. The model provides a framework for neuropsychologists to integrate issues that tend to co-occur in clients living with brain injury into a unified treatment plan.

Teasing apart trauma: neural oscillations differentiate individual cases of mild traumatic brain injury from post-traumatic stress disorder even when symptoms overlap

Post-traumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) are highly prevalent and closely related disorders. Affected individuals often exhibit substantially overlapping symptomatology - a major challenge for differential diagnosis in both military and civilian contexts. According to our symptom assessment, the PTSD group exhibited comparable levels of concussion symptoms and severity to the mTBI group. An objective and reliable system to uncover the key neural signatures differentiating these disorders would be an important step towards translational and applied clinical use. Here we explore use of MEG (magnetoencephalography)-multivariate statistical learning analysis in identifying the neural features for differential PTSD/mTBI characterisation. Resting state MEG-derived regional neural activity and coherence (or functional connectivity) across seven canonical neural oscillation frequencies (delta to high gamma) were used. The selected features were consistent and largely confirmatory with previously established neurophysiological markers for the two disorders. For regional power from theta, alpha and high gamma bands, the amygdala, hippocampus and temporal areas were identified. In line with regional activity, additional connections within the occipital, parietal and temporal regions were selected across a number of frequency bands. This study is the first to employ MEG-derived neural features to reliably and differentially stratify the two disorders in a multi-group context. The features from alpha and beta bands exhibited the best classification performance, even in cases where distinction by concussion symptom profiles alone were extremely difficult. We demonstrate the potential of using 'invisible' neural indices of brain functioning to understand and differentiate these debilitating conditions.

A global collaboration to study intimate partner violence-related head trauma: The ENIGMA consortium IPV working group

Intimate partner violence includes psychological aggression, physical violence, sexual violence, and stalking from a current or former intimate partner. Past research suggests that exposure to intimate partner violence can impact cognitive and psychological functioning, as well as neurological outcomes. These seem to be compounded in those who suffer a brain injury as a result of trauma to the head, neck or body due to physical and/or sexual violence. However, our understanding of the neurobehavioral and neurobiological effects of head trauma in this population is limited due to factors including difficulty in accessing/recruiting participants, heterogeneity of samples, and premorbid and comorbid factors that impact outcomes. Thus, the goal of the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium Intimate Partner Violence Working Group is to develop a global collaboration that includes researchers, clinicians, and other key community stakeholders. Participation in the working group can include collecting harmonized data, providing data for meta- and mega-analysis across sites, or stakeholder insight on key clinical research questions, promoting safety, participant recruitment and referral to support services. Further, to facilitate the mega-analysis of data across sites within the working group, we provide suggestions for behavioral surveys, cognitive tests, neuroimaging parameters, and genetics that could be used by investigators in the early stages of study design. We anticipate that the harmonization of measures across sites within the working group prior to data collection could increase the statistical power in characterizing how intimate partner violence-related head trauma impacts long-term physical, cognitive, and psychological health.

Diffusion Tensor Imaging Reveals White Matter Differences in Military Personnel Exposed to Trauma with and without Post-traumatic Stress Disorder

BACKGROUND

Post-traumatic stress disorder (PTSD) is a debilitating mental health condition that develops in response to exposure to a traumatic event. The purpose of this study was to investigate white matter differences using diffusion tensor imaging (DTI) in trauma exposed military personnel with and without PTSD.

METHODS

Data were acquired in compliance with the Hospital for Sick Children and Canadian Armed Forces Research Ethics Boards for the following groups: military personnel with PTSD (PTSD, n = 23), trauma exposed military personnel with no PTSD diagnosis (TE, n = 25) and civilian controls (CC, n =13) . All participants were male. DTI was acquired on a Siemens Trio 3T MRI. Maps of Fractional Anisotropy (FA), Mean Diffusivity (MD), Axial Diffusivity (AD), and Radial Diffusivity (RD) were analyzed using Tract-Based Spatial Statistics (TBSS).

RESULTS

In the PTSD and TE groups, FA was significantly greater within the hippocampus, corpus callosum, cingulum, and several associated white matter tracts. Elevated FA was shown to be largely due to reduced RD suggesting a possible structural substrate that underscores neurophysiological connectivity.

CONCLUSIONS

This study reinforces previous findings showing differences in DTI metrics within the limbic system in military personnel exposed to trauma with and without PTSD.

The additional burden of PTSD on functioning and depression in veterans with traumatic brain injury

BACKGROUND

Many United States veterans and active military with a history of traumatic brain injury (TBI) also experience challenges from comorbid posttraumatic stress disorder (PTSD), yet the additional burden of PTSD is not clear.

PURPOSE

To address this knowledge gap, this study examined the relationship of PTSD to cognitive, social, and physical functioning and depressive symptoms in veterans recently diagnosed with TBI.

METHODS

Veterans were recruited from a VA rehabilitation clinic. The Patient Competency Rating Scale and Center for Epidemiologic Studies Depression Scale measured functioning and depression, respectively. Chart review captured PTSD diagnosis.

FINDINGS

In the sample of 83 veterans, 65% had a current PTSD diagnosis. After controlling for sociodemographic variables and TBI severity, PTSD was a significant predictor of lower cognitive, social, and physical functioning and higher depressive symptomatology.

DISCUSSION

Clinicians should incorporate PTSD assessment in their work with veterans with TBI. Integrated behavioral health and rehabilitation interventions that provide strategies for veterans to manage TBI symptoms and PTSD are critical.

Blast in Context: The Neuropsychological and Neurocognitive Effects of Long-Term Occupational Exposure to Repeated Low-Level Explosives on Canadian Armed Forces' Breaching Instructors and Range Staff

Currently, there is strong interest within the military to better understand the effects of long-term occupational exposure to repeated low-level blast on health and performance. To gain traction on the chronic sequelae of blast, we focused on breaching—a tactical technique for gaining entry into closed/blocked spaces by placing explosives and maintaining a calculated safe distance from the detonation. Using a cross-sectional design, we compared the neuropsychological and neurocognitive profiles of breaching instructors and range staff to sex- and age-matched Canadian Armed Forces (CAF) controls. Univariate tests demonstrated that breaching was associated with greater post-concussive symptoms (Rivermead Post Concussion Symptoms Questionnaire) and lower levels of energy (RAND SF-36). In addition, breaching instructors and range staff were slower on a test that requires moving and thinking simultaneously (i.e., cognitive-motor integration). Next, using a multivariate approach, we explored the impact of other possible sources of injury, including concussion and prior war-zone deployment on the same outcomes. Concussion history was associated with higher post-concussive scores and musculoskeletal problems, whereas deployment was associated with higher post-concussive scores, but lower energy and greater PTSD symptomatology (using PCL-5). Our results indicate that although breaching, concussion, and deployment were similarly correlated with greater post-concussive symptoms, concussion history appears to be uniquely associated with altered musculoskeletal function, whereas deployment history appears to be uniquely associated with lower energy and risk of PTSD. We argue that the broader injury context must, therefore, be considered when studying the impact of repetitive low-level explosives on health and performance in military members.