Traumatic Brain Injury and Suicidal Behavior: A Review

Suicide Attempts and Ideation Among Veterans/Service Members and Non-Veterans Over 5 Years Following Traumatic Brain Injury: A Combined NIDILRR and VA TBI Model Systems Study

OBJECTIVE

This study compared rates of suicide attempt (SA) and suicidal ideation (SI) during the first 5 years after traumatic brain injury (TBI) among veterans and service members (V/SMs) in the Veterans Affairs (VA) and the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) Model Systems National Databases to each other and to non-veterans (non-Vs) in the NIDILRR database.

SETTING

Twenty-one NIDILRR and 5 VA TBI Model Systems (TBIMS) inpatient rehabilitation facilities in the United States.

PARTICIPANTS

Participants with TBI were discharged from rehabilitation alive, had a known military status recorded (either non-V or history of military service), and successful 1-, 2-, and/or 5-year follow-up interviews completed between 2009 and 2021. The year 1 cohort included 8737 unique participants (8347 with SA data and 3987 with SI data); the year 2 (7628 participants) and year 5 (4837 participants) cohorts both had similar demographic characteristics to the year 1 cohort.

DESIGN

Longitudinal design with data collected across TBIMS centers at 1, 2, and 5 years post-injury.

MAIN OUTCOMES AND MEASURES

History of SA in past year and SI in past 2 weeks assessed by the Patient Health Questionnaire-9 (PHQ-9). Patient demographics, injury characteristics, and rehabilitation outcomes were also assessed.

RESULTS

Full sample rates of SA were 1.9%, 1.5%, and 1.6%, and rates of SI were 9.6%, 10.1%, and 8.7% (respectively at years 1, 2, and 5). There were significant differences among groups based on demographic, injury-related, mental/behavioral health, and functional outcome variables. Characteristics predicting SA/SI related to mental health history, substance use, younger age, lower functional independence, and greater levels of disability.

CONCLUSIONS

Compared with participants with TBI in the NIDILRR system, higher rates of SI among V/SMs with TBI in the VA system appear associated with risk factors observed within this group, including mental/behavioral health characteristics and overall levels of disability.

Influence of affective instability on suicidal ideation beyond traumatic brain injury and posttraumatic stress disorder in veterans

OBJECTIVE

Mild traumatic brain injury (TBI) is associated with long-term consequences, including greater risk for posttraumatic stress disorder (PTSD) and suicidal ideation. Affective instability is also independently related to PTSD and suicidality, which may explain why some individuals continue to experience chronic psychiatric complaints following mild TBI. The purpose of the present study was to evaluate affective instability as a key factor for PTSD and suicidal ideation among Veterans with and without TBI.

METHOD

Participants (N = 299 Veterans; 86.96% male) completed the Personality Assessment Inventory (PAI) and structured clinical interviews for TBI and psychiatric diagnoses. Hierarchical linear regression was used to evaluate main and interaction effects.

RESULTS

There were no significant differences in affective instability (p = 0.140) or suicidal ideation (p = 0.453) between Veterans with or without TBI. Individuals with TBI were more likely to have a PTSD diagnosis (p = 0.001). Analyses evaluating PTSD diagnosis as an outcome indicated a main effect of affective instability (p < 0.001), but not TBI (p = 0.619). Analyses evaluating suicidal ideation as an outcome demonstrated an interaction effect between PTSD and affective instability beyond the effects of TBI (p = 0.034).

CONCLUSIONS

Severe Affective instability appears to be a key factor in suicidal ideation among Veterans beyond TBI or PTSD history. PTSD was more strongly associated with suicidality at lower and moderate levels of affective instability. At severe levels of affective instability, however, Veterans with and without PTSD experienced suicidal ideation at similar rates. Findings suggests that high levels of affective instability not better explained by other psychiatric conditions confers similar suicidality risk to that of PTSD in a Veteran population.

Systematic review and evidence gap mapping of biomarkers associated with neurological manifestations in patients with COVID-19

OBJECTIVE

This study aimed to synthesize the existing evidence on biomarkers related to coronavirus disease 2019 (COVID-19) patients who presented neurological events.

METHODS

A systematic review of observational studies (any design) following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and the Cochrane Collaboration recommendations was performed (PROSPERO: CRD42021266995). Searches were conducted in PubMed and Scopus (updated April 2023). The methodological quality of nonrandomized studies was assessed using the Newcastle‒Ottawa Scale (NOS). An evidence gap map was built considering the reported biomarkers and NOS results.

RESULTS

Nine specific markers of glial activation and neuronal injury were mapped from 35 studies published between 2020 and 2023. A total of 2,237 adult patients were evaluated in the included studies, especially during the acute phase of COVID-19. Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) biomarkers were the most frequently assessed (n = 27 studies, 77%, and n = 14 studies, 40%, respectively). Although these biomarkers were found to be correlated with disease severity and worse outcomes in the acute phase in several studies (p < 0.05), they were not necessarily associated with neurological events. Overall, 12 studies (34%) were judged as having low methodological quality, 9 (26%) had moderate quality, and 9 (26%) had high quality.

CONCLUSIONS

Different neurological biomarkers in neurosymptomatic COVID-19 patients were identified in observational studies. Although the evidence is still scarce and conflicting for some biomarkers, well-designed longitudinal studies should further explore the pathophysiological role of NfL, GFAP, and tau protein and their potential use for COVID-19 diagnosis and management.

Examining the Relationship Between Sleep Apnea Diagnosis and Suicide Risk in Veterans With Traumatic Brain Injury: A VA TBI Model Systems Study

OBJECTIVE

Obstructive sleep apnea (OSA) is a common sleep disorder in people with traumatic brain injury (TBI). Although sleep disturbances have been associated with an increased risk of suicide compared with the general population, the relationship between OSA and suicide risk after TBI is not well documented. In this study, we hypothesized that OSA diagnosis would predict suicide risk in veterans with TBI.

SETTING

Five Veterans Affairs (VA) Polytrauma Rehabilitation Centers.

PARTICIPANTS

Participants were drawn from the VA TBI Model Systems study, with follow-up interviews at year 1 ( n = 392), year 2 ( n = 444), year 5 ( n = 498), or year 10 ( n = 252) post-TBI (7.8%-14.5% follow-up attrition).

DESIGN

This was a retrospective analysis from observational data using logistic regression with repeated measurements. Suicide ideation and suicide attempts were examined as outcomes at each follow-up to evaluate the relationship between OSA and suicide risk after adjusting for other risk factors determined a priori via literature review.

MAIN MEASURES

Suicidal ideation (Patient Health Questionnaire-9 item 9), suicide attempt during the past year (self-reported), and OSA diagnosis (self-reported).

RESULTS

Contrary to study hypotheses, OSA diagnosis had no statistically significant association with suicide ideation or attempt after accounting for known predictors. However, greater depression symptoms, headache severity, and pre-TBI suicidal ideation and attempts predicted suicide risk at follow-up after accounting for other predictors.

CONCLUSIONS

Results of this study did not support a relationship between OSA and suicide risk, possibly due to methodological limitations of OSA measurement. Future research on this topic should include objective measures of OSA severity and OSA treatment including adherence. Although suicide is a low base rate occurrence, the impact is disastrous and further research is needed to mitigate suicide risk.

Neurological toll of COVID-19

The first case of coronavirus illness was discovered in Wuhan, China, in January 2020 and quickly spread worldwide within the next couple of months. The condition was initially only linked with respiratory disorders. After the evolution of various variants of the SARS-CoV-2, the critical impact of the virus spread to multiple organs and soon, neurological disorder manifestations started to appear in the infected patients. The review is focused on the manifestation of various neurological disorders linked with both the central nervous system and peripheral nervous system. Disorders such as cytokine release syndrome, encephalitis, acute stroke, and Bell's palsy are given specific attention and psychological manifestations are also investigated. For a clear conclusion, cognitive impairment, drug addiction disorders, mood and anxiety disorders, and post-traumatic stress disorder are all fully examined. The association of the SARS-CoV-2 with neurological disorders and pathway is yet to be clear. For better understanding, the explanation of the possible mechanism of viral infection influencing the nervous system is also attempted in the review. While several vaccines and drugs are already involved in treating the SARS-CoV-2 condition, the disease is still considered fatal and more likely to leave permanent neurological damage, which leads to an essential requirement for more research to explore the neurological toll of the COVID-19 disease.

Chronic cerebral aspects of long COVID, post-stroke syndromes and similar states share their pathogenesis and perispinal etanercept treatment logic

The chronic neurological aspects of traumatic brain injury, post‐stroke syndromes, long COVID‐19, persistent Lyme disease, and influenza encephalopathy having close pathophysiological parallels that warrant being investigated in an integrated manner. A mechanism, common to all, for this persistence of the range of symptoms common to these conditions is described. While TNF maintains cerebral homeostasis, its excessive production through either pathogen‐associated molecular patterns or damage‐associated molecular patterns activity associates with the persistence of the symptoms common across both infectious and non‐infectious conditions. The case is made that this shared chronicity arises from a positive feedback loop causing the persistence of the activation of microglia by the TNF that these cells generate. Lowering this excess TNF is the logical way to reducing this persistent, TNF‐maintained, microglial activation. While too large to negotiate the blood‐brain barrier effectively, the specific anti‐TNF biological, etanercept, shows promise when administered by the perispinal route, which allows it to bypass this obstruction.

Number of traumatic brain injuries and temporal associations with depression: A register-based cohort study

OBJECTIVE

To explore the association of the number of traumatic brain injuries (TBIs) and temporal associations with the subsequent risk of depression in the population.

METHODS

National register-based cohort study on all individuals registered with TBI (ICD-10: S06, ICD-8: 85.0-85.5) from 1977 to 2015 in Denmark (n = 494,216) and a sex- and age-matched reference population (n = 499,505). The associations with the number of TBIs and time to depression (0-6, 7-12 and more than 12 months following TBI) were analyzed using Cox proportional hazard regression.

RESULTS

During a follow-up of mean 14.5 (SD 11.3) years, a total of 27,873 (5.6%) individuals who had at least one TBI and 15,195 (3.0%) in the reference population were diagnosed with a depression. First-time TBI was associated with a higher risk of depression in both men (HR = 1.73 [95% CI:1.67-1.79]) and women (HR = 1.66 [95% CI:1.61-1.70]) after multiple adjustments for educational status and comorbidities including previous depression, and the association became stronger in a dose-response association with the number of TBIs (test for trend p < 0.01). The HRs for depression were highest the first 6 months after the TBI in both men (HR = 5.69 [95% CI:4.66-6.94]) and women (HR = 4.55 [95% CI:3.93-5.26]) and decreased gradually the following year but remained elevated from one year after TBI until end of follow-up independent of the number of TBIs (p < 0.01). The associations did not vary with age or calendar time.

CONCLUSION

Traumatic brain injury is associated with a higher risk of depression, especially in the first months after TBI and the risk increases with the number of TBIs.

Periodontal Pathogens and Neuropsychiatric Health

Increasing evidence incriminates low-grade inflammation in cardiovascular, metabolic diseases, and neuropsychiatric clinical conditions, all important causes of morbidity and mortality. One of the upstream and modifiable precipitants and perpetrators of inflammation is chronic periodontitis, a polymicrobial infection with Porphyromonas gingivalis (P. gingivalis) playing a central role in the disease pathogenesis. We review the association between P. gingivalis and cardiovascular, metabolic, and neuropsychiatric illness, and the molecular mechanisms potentially implicated in immune upregulation as well as downregulation induced by the pathogen. In addition to inflammation, translocation of the pathogens to the coronary and peripheral arteries, including brain vasculature, and gut and liver vasculature has important pathophysiological consequences. Distant effects via translocation rely on virulence factors of P. gingivalis such as gingipains, on its synergistic interactions with other pathogens, and on its capability to manipulate the immune system via several mechanisms, including its capacity to induce production of immune-downregulating micro-RNAs. Possible targets for intervention and drug development to manage distal consequences of infection with P. gingivalis are also reviewed.

Severe Spinal Cord Injury in Rats Induces Chronic Changes in the Spinal Cord and Cerebral Cortex Metabolism, Adjusted by Thiamine That Improves Locomotor Performance

Our study aims at developing knowledge-based strategies minimizing chronic changes in the brain after severe spinal cord injury (SCI). The SCI-induced long-term metabolic alterations and their reactivity to treatments shortly after the injury are characterized in rats. Eight weeks after severe SCI, significant mitochondrial lesions outside the injured area are demonstrated in the spinal cord and cerebral cortex. Among the six tested enzymes essential for the TCA cycle and amino acid metabolism, mitochondrial 2-oxoglutarate dehydrogenase complex (OGDHC) is the most affected one. SCI downregulates this complex by 90% in the spinal cord and 30% in the cerebral cortex. This is associated with the tissue-specific changes in other enzymes of the OGDHC network. Single administrations of a pro-activator (thiamine, or vitamin B1, 1.2 mmol/kg) or a synthetic pro-inhibitor (triethyl glutaryl phosphonate, TEGP, 0.02 mmol/kg) of OGDHC within 15–20 h after SCI are tested as protective strategies. The biochemical and physiological assessments 8 weeks after SCI reveal that thiamine, but not TEGP, alleviates the SCI-induced perturbations in the rat brain metabolism, accompanied by the decreased expression of (acetyl)p53, increased expression of sirtuin 5 and an 18% improvement in the locomotor recovery. Treatment of the non-operated rats with the OGDHC pro-inhibitor TEGP increases the p53 acetylation in the brain, approaching the brain metabolic profiles to those after SCI. Our data testify to an important contribution of the OGDHC regulation to the chronic consequences of SCI and their control by p53 and sirtuin 5.

Factors Increasing Risk of Suicide after Traumatic Brain Injury: A State-of-the-Science Review of Military and Civilian Studies

Primary Objective: Survey TBI literature to identify evidence of risk for post-injury suicide.Literature Selection: Search terms ((traumatic brain injury OR TBI) AND (suicidality OR suicidal behaviour OR suicidal ideation)) entered in PubMed, OVID Medline, PsychInfo, and Web of Science for papers published in print 01/01/1997 to 06/30/2019.Analysis of Literature: Authors screened abstracts, excluding duplicates and articles not meeting inclusion/exclusion criteria. Full papers were reviewed to make final exclusions. Data were extracted from 40 papers included co- and premorbid disorders, demographics, injury-related and psychological factors.Results: Persons with TBI have a higher risk for suicide than the general population. Reviewed articles reported comorbid depression and/or PTSD as risk factors for post-TBI suicide. Co- or premorbid substance misuse, sex, and sleep disturbance moderate risk. Quality of the literature was limited by sample size, the predominance of male participants, and inconsistency in reporting of findings.Conclusions: Comorbid depression and PTSD are significant post-TBI risk factors for suicide. Several variables combine to moderate or mediate TBI's connection with suicide. Civilian and military clinician cross-talk and consistent reporting of results from reproducible studies of post-TBI suicide risk factors could improve prevention and treatment efforts in veterans and civilians.

Psychological Stress-Induced Immune Response and Risk of Alzheimer's Disease in Veterans from Operation Enduring Freedom and Operation Iraqi Freedom

PURPOSE

Psychological stress is a significant health problem in veterans and their family members. Traumatic brain injury (TBI) and stress lead to the onset, progression, and worsening of several inflammatory and neurodegenerative diseases in veterans and civilians. Alzheimer's disease (AD) is a progressive, irreversible neuroinflammatory disease that causes problems with memory, thinking, and behavior. TBIs and chronic psychological stress cause and accelerate the pathology of neuroinflammatory diseases such as AD. However, the precise molecular and cellular mechanisms governing neuroinflammation and neurodegeneration are currently unknown, especially in veterans. The purpose of this review article was to advance the hypothesis that stress and TBI-mediated immune response substantially contribute and accelerate the pathogenesis of AD in veterans and their close family members and civilians.

METHODS

The information in this article was collected and interpreted from published articles in PubMed between 1985 and 2020 using the key words stress, psychological stress, Afghanistan war, Operation Enduring Freedom (OEF), Iraq War, Operation Iraqi Freedom (OIF), Operation New Dawn (OND), traumatic brain injury, mast cell and stress, stress and neuroimmune response, stress and Alzheimer's disease, traumatic brain injury, and Alzheimer's disease.

FINDINGS

Chronic psychological stress and brain injury induce the generation and accumulation of beta-amyloid peptide, amyloid plaques, neurofibrillary tangles, and phosphorylation of tau in the brain, thereby contributing to AD pathogenesis. Active military personnel and veterans are under enormous psychological stress due to various war-related activities, including TBIs, disabilities, fear, new environmental conditions, lack of normal life activities, insufficient communications, explosions, military-related noise, and health hazards. Brain injury, stress, mast cell, and other immune cell activation can induce headache, migraine, dementia, and upregulate neuroinflammation and neurodegeneration in veterans of Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn. TBIs, posttraumatic stress disorder, psychological stress, pain, glial activation, and dementia in active military personnel, veterans, or their family members can cause AD several years later in their lives. We suggest that there are increasing numbers of veterans with TBIs and stress and that these veterans may develop AD late in life if no appropriate therapeutic intervention is available.

IMPLICATIONS

Per these published reports, the fact that TBIs and psychological stress can accelerate the pathogenesis of AD should be recognized. Active military personnel, veterans, and their close family members should be evaluated regularly for stress symptoms to prevent the pathogenesis of neurodegenerative diseases, including AD.

Interoceptive deficits differentiate suicide groups and associate with self-injurious thoughts and behaviors in a military sample

OBJECTIVE

Previous research shows that interoceptive deficits are associated with harmful behaviors such as nonsuicidal self-injury (NSSI), eating disorder pathology, and suicide attempts. The present study replicates and extends this area of research by examining the association between interoceptive deficits and suicidality in a military sample.

METHOD

In Study 1, respondents to an online survey (N = 134) answered self-report questionnaires related to interoceptive deficits. Study 2 consisted of a secondary data analysis of 3,764 military service members who had previously completed questionnaires on interoceptive indicators, NSSI, suicide thoughts and attempts, and other psychopathology.

RESULTS

Study 1 demonstrated that our interoceptive deficits latent variable had adequate psychometric properties. In Study 2, multigroup confirmatory factor analysis showed that scores on the interoceptive deficits latent variable were highest among suicide attempters, lowest among those with no suicide history, and intermediary among participants who had thought about but not attempted suicide. The interoceptive deficits latent variable was more strongly related to NSSI and suicidality than were posttraumatic stress disorder symptoms, hopelessness, gender, and age.

CONCLUSIONS

These results confirm-and extend to a military sample-previous research showing that interoceptive deficits can provide important information about suicide risk.

Psychopharmacology of Suicide

Despite the psychotherapeutic and pharmacotherapeutic advances in the treatment of depressive, anxiety, and psychotic disorders over the past several decades, the suicide rate in the United States has increased over the past 18 years. Medications are safer and more difficult to use in overdosing, but not necessarily more efficacious in bringing about complete remission of symptoms. The current article focuses on the theories and psychosocial and neurobiological correlates of suicide with the intent of formulating intervention strategies to prevent suicide. Particular attention is on medications that may contribute to suicidal ideation and behaviors and those that show evidence of reducing the risk of suicide. [Journal of Psychosocial Nursing and Mental Health Services, 57(12), 9-14.].