Psychiatric Diagnoses, Mental Health Utilization, High-Risk Behaviors, and Self-Directed Violence Among Veterans With Comorbid History of Traumatic Brain Injury and Substance Use Disorders

Impulsivity and Psychiatric Diagnoses as Mediators of Suicidal Ideation and Suicide Attempts Among Veterans With Traumatic Brain Injury

OBJECTIVE

Traumatic brain injury (TBI) is a risk factor for suicide, but questions related to mechanisms remain unanswered. Impulsivity is a risk factor for suicide and is a common sequela of TBI. The authors explored the relationships between TBI and both suicidal ideation and suicide attempts and explored whether impulsivity and comorbid psychiatric diagnoses mediate these relationships.

METHODS

This cross-sectional retrospective chart review study included 164 veterans enrolled in a previous study. Sixty-nine veterans had no TBI history, and 95 had a TBI history (mild, N=44; moderate, N=13; severe, N=12; and unclear severity, N=26). To examine the associations between TBI and suicidal ideation or suicide attempts, as well as potential mediators of these relationships, chi-square tests, t tests, and logistic regression models were used.

RESULTS

Unadjusted analyses indicated that veterans with TBI were more likely to report suicidal ideation; however, in analyses controlling for mediators, this relationship was no longer significant. Among veterans with TBI, suicidal ideation was related most strongly to high impulsivity (odds ratio=15.35, 95% CI=2.43-96.79), followed by depression (odds ratio=5.73, 95% CI=2.53-12.99) and posttraumatic stress disorder (odds ratio=2.57, 95% CI=1.03-6.42). TBI was not related to suicide attempts, yet suicide attempts were related to high impulsivity (odds ratio=6.95, 95% CI=1.24-38.75) and depression (odds ratio=3.89, 95% CI=1.56-9.40).

CONCLUSIONS

These findings suggest that impulsivity, followed by psychiatric diagnoses, most strongly mediate the relationships between TBI and both suicidal ideation and suicide attempts. Impulsivity may be mechanistically related to, and serve as a future treatment target for, suicidality among veterans with TBI.

Prevalence and Clinical Characteristics of Recreational and At-Risk/Problematic Gambling in a National Sample of U.S. Military Veterans

Gambling among U.S. military veterans is common, with more extensive involvement linked to gambling disorder and associated problems. This study examined associations between recreational gambling (RG) and at-risk/problem gambling (ARPG), and clinical measures (psychiatric disorders, substance use), behaviors (suicidality, homelessness, arrests) and functioning in a nationally representative sample of U.S. military veterans. Data were analyzed from 4069 veterans who participated in the National Health and Resilience in Veterans Study. Chi-square tests, analyses of variance (ANOVAs) and logistic regressions were conducted to examine unadjusted and adjusted associations between gambling group status and lifetime and current psychiatric diagnoses and behavioral and functioning measures. A significant minority of U.S. veterans reported gambling, with 27.3% (95% confidence interval [CI] 25.5-29.1%) exhibiting RG and 4.9% (95% CI 4.0-5.9%) screening positive for ARPG. The prevalence of ARPG was higher among younger, non-White, male veterans, while RG was more prevalent among retired veterans and those with higher household incomes relative to non-gambling (NG) individuals. ARPG was associated with greater trauma burden, lifetime and current psychiatric diagnoses, mental health treatment, alcohol and drug use disorders, suicidal ideation, homelessness, arrests, and poorer functioning relative to NG and RG, with stronger magnitude differences relative to NG. RG was associated with substance use disorders and arrest histories relative to NG. Results of the current study provide an up-to-date estimate of the current prevalence of RG and ARPG among U.S. veterans and underscore the importance of routine screening and monitoring of gambling problems, as well as interventions for ARPG in this population.

Timing matters: Sex differences in inflammatory and behavioral outcomes following repetitive blast mild traumatic brain injury

BACKGROUND

Repetitive blast-related mild traumatic brain injury (mTBI) caused by exposure to high explosives is increasingly common among warfighters as well as civilians. While women have been serving in military positions with increased risk of blast exposure since 2016, there are few published reports examining sex as a biological variable in models of blast mTBI, greatly limiting diagnosis and treatment capabilities. As such, here we examined outcomes of repetitive blast trauma in female and male mice in relation to potential behavioral, inflammatory, microbiome, and vascular dysfunction at multiple timepoints.

METHODS

In this study we utilized a well-established blast overpressure model to induce repetitive (3x) blast-mTBI in both female and male mice. Acutely following repetitive exposure, we measured serum and brain cytokine levels, blood-brain barrier (BBB) disruption, fecal microbial abundance, and locomotion and anxiety-like behavior in the open field assay. At the one-month timepoint, in female and male mice we assessed behavioral correlates of mTBI and PTSD-related symptoms commonly reported by Veterans with a history of blast-mTBI using the elevated zero maze, acoustic startle, and conditioned odorant aversion paradigms.

RESULTS

Repetitive blast exposure resulted in both similar (e.g., increased IL-6), and disparate (e.g., IL-10 increase only in females) patterns of acute serum and brain cytokine as well as gut microbiome changes in female and male mice. Acute BBB disruption following repetitive blast exposure was apparent in both sexes. While female and male blast mice both exhibited acute locomotor and anxiety-like deficits in the open field assay, only male mice exhibited adverse behavioral outcomes that lasted at least one-month.

DISCUSSION

Representing a novel survey of potential sex differences following repetitive blast trauma, our results demonstrate unique similar yet divergent patterns of blast-induced dysfunction in female vs. male mice and highlight novel targets for future diagnosis and therapeutic development.

Repetitive blast mild traumatic brain injury increases ethanol sensitivity in male mice and risky drinking behavior in male combat veterans

BACKGROUND

Mild traumatic brain injury (mTBI) is common in civilians and highly prevalent among military service members. mTBI can increase health risk behaviors (e.g., sensation seeking, impulsivity) and addiction risk (e.g., for alcohol use disorder (AUD)), but how mTBI and substance use might interact to promote addiction risk remains poorly understood. Likewise, potential differences in single vs. repetitive mTBI in relation to alcohol use/abuse have not been previously examined.

METHODS

Here, we examined how a history of single (1×) or repetitive (3×) blast exposure (blast-mTBI) affects ethanol (EtOH)-induced behavioral and physiological outcomes using an established mouse model of blast-mTBI. To investigate potential translational relevance, we also examined self-report responses to the Alcohol Use Disorders Identification Test-Consumption questions (AUDIT-C), a widely used measure to identify potential hazardous drinking and AUD, and used a novel unsupervised machine learning approach to investigate whether a history of blast-mTBI affected drinking behaviors in Iraq/Afghanistan Veterans.

RESULTS

Both single and repetitive blast-mTBI in mice increased the sedative properties of EtOH (with no change in tolerance or metabolism), but only repetitive blast potentiated EtOH-induced locomotor stimulation and shifted EtOH intake patterns. Specifically, mice exposed to repetitive blasts showed increased consumption "front-loading" (e.g., a higher rate of consumption during an initial 2-h acute phase of a 24-h alcohol access period and decreased total daily intake) during an intermittent 2-bottle choice condition. Examination of AUDIT-C scores in Iraq/Afghanistan Veterans revealed an optimal 3-cluster solution: "low" (low intake and low frequency), "frequent" (low intake and high frequency), and "risky" (high intake and high frequency), where Veterans with a history of blast-mTBI displayed a shift in cluster assignment from "frequent" to "risky," as compared to Veterans who were deployed to Iraq/Afghanistan but had no lifetime history of TBI.

CONCLUSIONS

Together, these results offer new insight into how blast-mTBI may give increase AUD risk and highlight the increased potential for adverse health risk behaviors following repetitive blast-mTBI.

Epidemiology of Comorbid Conditions Among Adults 50 Years and Older With Traumatic Brain Injury

OBJECTIVES

Aging individuals with traumatic brain injury (TBI) experience multiple comorbidities that can affect recovery from injury. The objective of this study was to describe the most commonly co-occurring comorbid conditions among adults 50 years and older with TBI.

SETTING

Level I Trauma centers.

PARTICIPANTS

Adults 50 years and older with moderate/severe TBI enrolled in the TBI-Model Systems (TBI-MS) from 2007 to 2014 (n = 2134).

DESIGN

A TBI-MS prospective cohort study.

MAIN MEASURES

International Classification of Disease-9th Revision codes collapsed into 45 comorbidity categories. Comorbidity prevalence estimates and trend analyses were conducted by age strata (50-54, 55-64, 65-74, 75-84, ≥85 years). A dimension reduction method, Treelet Transform, classified clusters of comorbidities that tended to co-occur.

RESULTS

The 3 most commonly occurring comorbid categories were hypertensive disease (52.6/100 persons), other diseases of the respiratory system (51.8/100 persons), and fluid component imbalances (43.7/100 persons). Treelet Transform classified 3 clusters of comorbid codes, broadly classified as (1) acute medical diseases/infections, (2) chronic conditions, and (3) substance abuse disorders.

CONCLUSION

This study provides valuable insight into comorbid conditions that co-occur among adults 50 years and older with TBI and provides a foundation for future studies to explore how specific comorbidities affect TBI recovery.

Blast-related disinhibition and risk seeking in mice and combat Veterans: Potential role for dysfunctional phasic dopamine release

Mild traumatic brain injury (mTBI) caused by exposure to high explosives has been called the "signature injury" of the wars in Iraq and Afghanistan. There is a wide array of chronic neurological and behavioral symptoms associated with blast-induced mTBI. However, the underlying mechanisms are not well understood. Here we used a battlefield-relevant mouse model of blast-induced mTBI and in vivo fast-scan cyclic voltammetry (FSCV) to investigate whether the mesolimbic dopamine system contributes to the mechanisms underlying blast-induced behavioral dysfunction. In mice, blast exposure increased novelty seeking, a behavior closely associated with disinhibition and risk for subsequent maladaptive behaviors. In keeping with this, we found that veterans with blast-related mTBI reported greater disinhibition and risk taking on the Frontal Systems Behavior Scale (FrSBe). In addition, in mice we report that blast exposure causes potentiation of evoked phasic dopamine release in the nucleus accumbens. Taken together these findings suggest that blast-induced changes in the dopaminergic system may mediate aspects of the complex array of behavioral dysfunctions reported in blast-exposed veterans.

Does trauma exposure predict prescription drug problems beyond the contribution of post-traumatic stress disorder and depression? An analysis of the Mind Your Heart cohort study

It is not clear from prior studies whether trauma exposure predicts substance use problems independent of psychiatric comorbidities. Most prior studies were cross-sectional in nature, and none focused on prescription drug problems. To address this gap in the literature, the current article is a secondary analysis of veterans from the Mind Your Heart prospective cohort study. The primary research question is whether trauma exposure predicts prescription drug problems even after controlling for major psychiatric symptoms, such as post-traumatic stress disorder and depression. Multinomial logistic regression was used to assess whether the 10-item lifetime Brief Trauma Questionnaire (e.g., serious car accidents, war traumas, life-threatening illness, natural disasters, physical, or sexual abuse) predicts prescription drug problems as determined by a self-report categorical question (three answer choices) over a 4-year follow-up time period (n = 661 [100%] at year 1; 83.4% at year 2; 85.9% at year 3; and 78.2% at year 4). Trauma exposure was positively associated with prescription drug problems in unadjusted and age-, sex-, and race-adjusted analyses at follow-up. After accounting for post-traumatic stress disorder (PTSD Checklist-17 Civilian Version) and depression (Patient Health Questionnaire-9) symptoms, trauma exposure was no longer associated with prescription drug problems at all time points (relative risk ratios range 0.91-1.47). These results were robust to different missing data strategies. Trauma exposure was not associated with prescription drug problems over a 4-year follow-up in a prospective cohort study of veterans. Future directions include detailed measures of prescription drug problems and recruitment from community sites.

Factors affecting increased risk for substance use disorders following traumatic brain injury: What we can learn from animal models

Recent studies have helped identify multiple factors affecting increased risk for substance use disorders (SUDs) following traumatic brain injury (TBI). These factors include age at the time of injury, repetitive injury and TBI severity, neurocircuits, neurotransmitter systems, neuroinflammation, and sex differences. This review will address each of these factors by discussing 1) the clinical and preclinical data identifying patient populations at greatest risk for SUDs post-TBI, 2) TBI-related neuropathology in discrete brain regions heavily implicated in SUDs, and 3) the effects of TBI on molecular mechanisms that may drive substance abuse behavior, like dopaminergic and glutamatergic transmission or neuroimmune signaling in mesolimbic regions of the brain. Although these studies have laid the groundwork for identifying factors that affect risk of SUDs post-TBI, additional studies are required. Notably, preclinical models have been shown to recapitulate many of the behavioral, cellular, and neurochemical features of SUDs and TBI. Therefore, these models are well suited for answering important questions that remain in future investigations.

Relationships between risky sexual behaviour, dysexecutive problems, and mental health in the years following interdisciplinary TBI rehabilitation

Little is known about the long-term consequences of traumatic brain injury (TBI) regarding risky sexual behaviour. The objectives of the study were (1) to compare risky sexual behaviour in a sample of individuals with TBI having received interdisciplinary rehabilitation with that of healthy controls, and (2) to explore the relationships between risky sexual behaviour, executive functions, and mental health in individuals with TBI. The study group consisted of 42 individuals with TBI with a mean age of 37.9 years (SD = 9.7), 12.8 years of education (SD = 3.3), and 3.3 years post-injury (SD = 4.3). Healthy controls consisted of 47 participants, with a mean age of 37.6 years (SD = 10.7), and 13 years of education (SD = 3). Risky sexual behaviour was measured with the Sexual Risk Survey and executive function with the Dysexecutive Questionnaire. Mental health measures included the Generalised Anxiety Disorder Scale, and the Patient Health Questionnaire for depression. Compared to healthy controls, individuals with TBI reported more dysexecutive and mental health problems, without differences in risky sexual behaviour. In individuals with TBI, risky sexual behaviour was associated with behavioural, cognitive and emotional dysexecutive problems, but not with anxiety or depression. It was concluded that special attention should be given to individuals with TBI showing difficulties in executive functions given their association with risky sexual behaviour.

Traumatic Brain Injury in United States Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Hispanic Veterans-A Review Using the PRISMA Method

Traumatic brain injury (TBI) is commonly defined by Menon et al. as an "alteration of the brain function, or other evidence of brain pathology, caused by an external force." TBI can be caused by penetrating trauma to the head in which the magnitude of the injury is dependent on the magnitude of the forces that are applied to the head. The consequences of TBI can range from minimal to severe disability and even death. The major objectives of this systematic review are to survey the current literature on Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) Hispanic veterans with TBI. To complete this analysis, the Preferred Reporting Items for Systematic Reviews and MetaAnalysis (PRISMA) identified 875 articles in common and retrieved a total of 34 articles that met the inclusion criteria, consisted of OEF/OIF Hispanic veterans, reported quantitative data, and were conducted with adult U.S. veterans living in the United States. Since TBI diagnosis was unclear in most articles, only five articles that used the VATBIST instrument were analyzed. The results suggested that there is a lack of research on OEF/OIF Hispanic veterans and Hispanic subgroups. Future studies need to be conducted to consider minority groups while analyzing data involving TBI.

A national cohort study of the association between the polytrauma clinical triad and suicide-related behavior among US Veterans who served in Iraq and Afghanistan

OBJECTIVES

We examined the association of posttraumatic stress disorder (PTSD), traumatic brain injury, and chronic pain-the polytrauma clinical triad (PCT)-independently and with other conditions, with suicide-related behavior (SRB) risk among Operation Enduring Freedom (OEF; Afghanistan) and Operation Iraqi Freedom (OIF) veterans.

METHODS

We used Department of Veterans Affairs (VA) administrative data to identify OEF and OIF veterans receiving VA care in fiscal years 2009-2011; we used International Classification of Diseases, Ninth Revision, Clinical Modification codes to characterize 211652 cohort members. Descriptive statistics were followed by multinomial logistic regression analyses predicting SRB.

RESULTS

Co-occurrence of PCT conditions was associated with significant increase in suicide ideation risk (odds ratio [OR] = 1.9; 95% confidence interval [CI]=1.5, 2.4) or attempt and ideation (OR=2.6; 95% CI=1.5, 4.6), but did not exceed increased risk with PTSD alone (ideation: OR=2.3; 95% CI=2.0, 2.6; attempt: OR=2.0; 95% CI=1.4, 2.9; ideation and attempt: OR=1.8; 95% CI=1.2, 2.8). Ideation risk was significantly elevated when PTSD was comorbid with depression (OR=4.2; 95% CI=3.6, 4.8) or substance abuse (OR=4.7; 95% CI = 3.9, 5.6).

CONCLUSIONS

Although PCT was a moderate SRB predictor, interactions among PCT conditions, particularly PTSD, and depression or substance abuse had larger risk increases.

Dual diagnosis among veterans in the United States

Purpose

– Over the course of their service, veterans are exposed to elevated levels of chronic stress that contribute to a greater prevalence of mental illness than observed in the general population. When mental illness is present, comorbidity is normative. Convergent evidence suggests that co-occurring substance use and mental illness is among the most prevalent forms of comorbidity within veteran samples. The purpose of this paper is to explore issues associated with dual diagnoses among veterans in the USA.

Design/methodology/approach

– Research on dual diagnoses among veterans was reviewed and consolidated for presentation into three substantive content areas consisting of prevalence, associated conditions, and treatment of dual diagnoses.

Findings

– Dually diagnosed veterans represent a group at particularly high risk for myriad adverse biopsychosocial and treatment outcomes, including poor health, suicidality, violence or aggressive behavior, arrest, homelessness, and unemployment. A comprehensive strategy has been implemented within the Veterans Health Administration to address dual diagnosis and related problems. Additional research is required to more readily identify co-occurring substance use and mental illness and to refine integrated intervention approaches to minimize burden while improving treatment outcomes for veterans and their families.

Originality/value

– The current review includes a wide range of research spanning more than two decades and describing dual diagnosis among combat veterans of all modern eras. Areas in need of further research (e.g. dual diagnosis among female veterans; early detection of psychopathology and fully integrated care among returning veterans) are identified and discussed.

Definition of Impulsivity and Related Terms Following Traumatic Brain Injury: A Review of the Different Concepts and Measures Used to Assess Impulsivity, Disinhibition and other Related Concepts

Impulsivity is a common and debilitating sequela following traumatic brain injury (TBI), but there is no consensual definition or measure to assess this construct. The following review aims to elucidate the differences and resemblances between impulsivity, disinhibition and other related terms following brain injury and the instruments that are commonly used to measure these constructs. To do so, a search through different databases was conducted in order to find articles that mention and define impulsivity, disinhibition, impulse control, regulation deficits, dyscontrol and risky behavior. The concepts that stand out from the literature, the measures used, the similarities, the differences between these concepts are observed. The fit with the UPPS model of impulsivity, according to which impulsivity is a multidimensional concept composed of four distinct dimensions (urgency, perseverance, premeditation and sensation-seeking) is discussed.