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.

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.

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 (ß = -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 (ß = -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 (ß = -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.

Negative global metacognitive biases are associated with depressive and posttraumatic stress disorder symptoms and improve with targeted or game-based cognitive training.

OBJECTIVE: Metacognition is disrupted in several clinical populations. One aspect of metacognition, global metacognitive bias (difference between objective and self-reported abilities), has shown to be particularly relevant to clinical functioning. However, previous studies of global metacognitive biases in populations with elevated depressive/posttraumatic stress disorder (PTSD) symptoms have not measured objective and self-reported abilities relative to normative samples, limiting the quantification of biases. Additionally, few studies have examined whether cognitive interventions can improve metacognitive biases or how this relates to depressive/PTSD symptom severity. METHOD: A total of 84 participants with mild traumatic brain injury (77% veterans) performed PTSD and depression assessments along with self-reported and objective measures of global cognition. Age-adjusted norm-based z scores were used for self-reported and objective cognition, and bias was calculated by subtracting objective minus self-report scores. Participants then received 13 weeks of targeted cognitive training or entertainment games training (both providing performance feedback). Participants were assessed at baseline, immediately posttraining, and 3 months posttraining. RESULTS: We found large negative metacognitive biases in those with clinically significant severity of depressive symptoms (z score difference = -1.77), PTSD symptoms (-1.47), and depressive + PTSD symptoms (-2.29). Metacognitive biases improved after both targeted and entertainment training and was associated with reductions in depressive/PTSD symptom severity (r = -.41/-.42, respectively), led by the entertainment training group (r = -.54/-.46, respectively). CONCLUSIONS: These findings show that clinically significant severity of depressive/PTSD symptoms is associated with substantial negative global metacognitive biases and preliminarily suggests that cognitive training may improve these biases and depressive/PTSD symptom severity. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Neurocognitive and psychiatric outcomes associated with postacute COVID-19 infection without severe medical complication: a meta-analysis.

BACKGROUND: Cognitive symptoms are often reported by those with a history of COVID-19 infection. No comprehensive meta-analysis of neurocognitive outcomes related to COVID-19 exists despite the influx of studies after the COVID-19 pandemic. This study meta-analysed observational research comparing cross-sectional neurocognitive outcomes in adults with COVID-19 (without severe medical/psychiatric comorbidity) to healthy controls (HCs) or norm-referenced data. METHODS: Data were extracted from 54 studies published between January 2020 and June 2023. Hedges' g was used to index effect sizes, which were pooled using random-effects modelling. Moderating variables were investigated using meta-regression and subgroup analyses. RESULTS: Omnibus meta-analysis of 696 effect sizes extracted across 54 studies (COVID-19 n=6676, HC/norm-reference n=12 986; average time since infection=~6 months) yielded a small but significant effect indicating patients with COVID-19 performed slightly worse than HCs on cognitive measures (g=-0.36; 95% CI=-0.45 to -0.28), with high heterogeneity (Q=242.30, p<0.001, τ=0.26). Significant within-domain effects was yielded by cognitive screener (g=-0.55; 95% CI=-0.75 to -0.36), processing speed (g=-0.44; 95% CI=-0.57 to -0.32), global cognition (g=-0.40; 95% CI=-0.71 to -0.09), simple/complex attention (g=-0.38; 95% CI=-0.46 to -0.29), learning/memory (g=-0.34; 95% CI=-0.46 to -0.22), language (g=-0.34; 95% CI=-0.45 to -0.24) and executive function (g=-0.32; 95% CI=-0.43 to -0.21); but not motor (g=-0.40; 95% CI=-0.89 to 0.10), visuospatial/construction (g=-0.09; 95% CI=-0.23 to 0.05) and orientation (g=-0.02; 95% CI=-0.17 to 0.14). COVID-19 samples with elevated depression, anxiety, fatigue and disease severity yielded larger effects. CONCLUSION: Mild cognitive deficits are associated with COVID-19 infection, especially as detected by cognitive screeners and processing speed tasks. We failed to observe clinically meaningful cognitive impairments (as measured by standard neuropsychological instruments) in people with COVID-19 without severe medical or psychiatric comorbidities.

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.

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.

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.

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; ß = 0.16; p = .0002), and worse self-reported depression (ß = 0.17; p = .0001), anxiety (ß = 0.15; p = .0007), sleep (ß = 0.10; p = .0233), and functional outcomes (ß = 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.

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.

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.

Changes in Mild Neurocognitive Disorder Status in Mobility Limited Older Primary Care Patients: Implications for Rehabilitative Care.

OBJECTIVE: The aim of the study is to identify potential rehabilitative treatment targets associated with participants' annual cognitive status. DESIGN: A cohort study patients with self-reported mobility limitation who completed neuropsychological, physical performance testing, and questionnaires at baseline to 2-year follow-up were categorized into three groups (persistently cognitively normal, nonpersistent mild neurocognitive disorder, and persistently mild neurocognitive disorder) based on their annual cognitive status using baseline, years 1 and 2 performance on Hopkins Verbal Learning, Trail Making, and Digit Symbol Substitution Tests. Repeated measures multinomial regression analysis was used to examine the differences between groups and associated characteristics. RESULTS: Study included 349 participants (mean age, 76 ± 7) with 57% of participants were persistently cognitively normal, 16% persistently mild neurocognitive disorder, and 27% nonpersistent mild neurocognitive disorder over 2 yrs of follow-up. Faster gait speed (relative risk reduction, 0.64-0.89) was associated with risk reduction and increase in depressive symptoms (relative risk reduction, 1.09-1.12) was associated with greater risk of being classified into the nonpersistent or persistently mild neurocognitive disorder compared with persistently cognitively normal. CONCLUSIONS: Variability across cognitive status over time was observed. Gait speed and depressive symptoms were modifiable risk factors associated with nonpersistent and persistent mild neurocognitive disorder status. This study reinforces the potential benefit of multifaceted rehabilitation for preventing and treating older adults with mobility and/or cognitive problems.

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.

Association of War Zone-Related Stress With Alterations in Limbic Gray Matter Microstructure.

Importance: Military service members returning from theaters of war are at increased risk for mental illness, but despite high prevalence and substantial individual and societal burden, the underlying pathomechanisms remain largely unknown. Exposure to high levels of emotional stress in theaters of war and mild traumatic brain injury (mTBI) are presumed factors associated with risk for the development of mental disorders. Objective: To investigate (1) whether war zone-related stress is associated with microstructural alterations in limbic gray matter (GM) independent of mental disorders common in this population, (2) whether associations between war zone-related stress and limbic GM microstructure are modulated by a history of mTBI, and (3) whether alterations in limbic GM microstructure are associated with neuropsychological functioning. Design, Setting, and Participants: This cohort study was part of the TRACTS (Translational Research Center for TBI and Stress Disorders) study, which took place in 2010 to 2014 at the Veterans Affair Rehabilitation Research and Development TBI National Network Research Center. Participants included male veterans (aged 18-65 years) with available diffusion tensor imaging data enrolled in the TRACTS study. Data analysis was performed between December 2017 to September 2021. Exposures: The Deployment Risk and Resilience Inventory (DRRI) was used to measure exposure to war zone-related stress. The Boston Assessment of TBI-Lifetime was used to assess history of mTBI. Stroop Inhibition (Stroop-IN) and Inhibition/Switching (Stroop-IS) Total Error Scaled Scores were used to assess executive or attentional control functions. Main Outcomes and Measures: Diffusion characteristics (fractional anisotropy of tissue [FAT]) of 16 limbic and paralimbic GM regions and measures of functional outcome. Results: Among 384 male veterans recruited, 168 (mean [SD] age, 31.4 [7.4] years) were analyzed. Greater war zone-related stress was associated with lower FAT in the cingulate (DRRI-combat left: P = .002, partial r = -0.289; DRRI-combat right: P = .02, partial r = -0.216; DRRI-aftermath left: P = .004, partial r = -0.281; DRRI-aftermath right: P = .02, partial r = -0.219), orbitofrontal (DRRI-combat left medial orbitofrontal cortex: P = .02, partial r = -0.222; DRRI-combat right medial orbitofrontal cortex: P = .005, partial r = -0.256; DRRI-aftermath left medial orbitofrontal cortex: P = .02, partial r = -0.214; DRRI-aftermath right medial orbitofrontal cortex: P = .005, partial r = -0.260; DRRI-aftermath right lateral orbitofrontal cortex: P = .03, partial r = -0.196), and parahippocampal (DRRI-aftermath right: P = .03, partial r = -0.191) gyrus, as well as with higher FAT in the amygdala-hippocampus complex (DRRI-combat: P = .005, partial r = 0.254; DRRI-aftermath: P = .02, partial r = 0.223). Lower FAT in the cingulate-orbitofrontal gyri was associated with impaired response inhibition (Stroop-IS left cingulate: P < .001, partial r = -0.440; Stroop-IS right cingulate: P < .001, partial r = -0.372; Stroop-IS left medial orbitofrontal cortex: P < .001, partial r = -0.304; Stroop-IS right medial orbitofrontal cortex: P < .001, partial r = -0.340; Stroop-IN left cingulate: P < .001, partial r = -0.421; Stroop-IN right cingulate: P < .001, partial r = -0.300; Stroop-IN left medial orbitofrontal cortex: P = .01, partial r = -0.223; Stroop-IN right medial orbitofrontal cortex: P < .001, partial r = -0.343), whereas higher FAT in the mesial temporal regions was associated with improved short-term memory and processing speed (left amygdala-hippocampus complex: P < .001, partial r = -0.574; right amygdala-hippocampus complex: P < .001, partial r = 0.645; short-term memory left amygdala-hippocampus complex: P < .001, partial r = 0.570; short-term memory right amygdala-hippocampus complex: P < .001, partial r = 0.633). A history of mTBI did not modulate the association between war zone-related stress and GM diffusion. Conclusions and Relevance: This study revealed an association between war zone-related stress and alteration of limbic GM microstructure, which was associated with cognitive functioning. These results suggest that altered limbic GM microstructure may underlie the deleterious outcomes of war zone-related stress on brain health. Military service members may benefit from early therapeutic interventions after deployment to a war zone.

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.

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.

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.

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 among clinical variables and anger differ by early life adversity among post-9/11 veterans.

Maladaptive anger and aggression are common in US military veterans and increase risk for impaired social relationships and functioning, justice-involvement and violence. Early life (before age 18) adversity predisposes veterans to later life psychopathology, though the link to increased later life anger is unclear. We analysed cross-sectional data of 158 post-9/11 veterans from the Translational Research Center for Traumatic Brain Injury and Stress Disorders study with and without a history of early life adversity (ns = 109 and 49, respectively). We explored the relationship among major clinical variables and current veteran anger (Dimensions of Anger Reactions) and whether the associations with these variables differed among participants with and without a history of retrospective self-reported early life adversity (Childhood Trauma Questionnaire). In the overall sample, posttraumatic stress disorder (PTSD) and depression severities had the strongest associations with current veteran anger (ßs = 0.261 and 0.263; p-values = 0.0022 and 0.0103, respectively). In the subsample without early life adversity, only PTSD severity was significantly associated with anger (ß = 0.577, p = 0.0004). In the early life adversity subsample, this strong association weakened and was no longer significant (ß = 0.168, p = 0.1007); instead, anxiety and depression severities showed moderate associations with anger (ßs = 0.243 and 0.287, p-values = 0.0274 and 0.0130, respectively). Findings suggest that clinicians should screen veterans with history of early life adversity for depression and anxiety when anger is present.