Associations of Lifetime Traumatic Brain Injury Characteristics With Prospective Suicide Attempt Among Deployed US Army Soldiers

The Prevention of Suicide in Older Military Veterans

Suicidal behavior among older military veterans is an important medical and social problem. The goal of this literature review is to discuss this underappreciated issue and identify suicide preventive interventions that can be utilized with the older military veteran population. Older veterans experience psychiatric, medical, and social problems associated with their age and/or military experience that can contribute to suicide risk. These problems include relationship losses through death or estrangement, depression, cognitive decline, loneliness, isolation, frailty, mobility issues, and chronic pain. Therefore, older veterans face a unique set of challenges. Suicide prevention in older veterans should take a multipronged approach which includes screening for suicidality, management of psychiatric and medical disorders, social assistance, safety planning, lethal means restriction, and involving family members in the veteran's healthcare. Family members should be included in the safety planning process when possible. Gatekeeper training programs can be utilized to train individuals who are working with older veterans to reduce suicides amongst this age group.

The Relationship Between Traumatic Brain Injury and Suicide: A Systematic Review of Risk Factors

Objective

Traumatic brain injury (TBI) significantly increases the risk of suicidal ideation (SI) and behaviors due to neurobiological changes, cognitive impairments, and emotional dysregulation. This review consolidates current evidence on the relationship between TBI and suicide, identifying key risk factors and underlying mechanisms, and highlights the need for further research, especially in civilian populations.

Method

Studies were identified from an online search of PubMed, Web of Science, Cochrane Library, Embase, and Scopus databases with studies published from 2014 to 2024. This review has been registered on Prospero (number CRD42024574643).

Results

Factors indicated such as external causes of injury, comorbidities like depression and substance use disorders, and post-TBI symptoms consistently influence suicide risk. Advanced predictive models emphasize the role of psychological symptoms, particularly depressive features, in forecasting SI post-TBI, underscoring the need for targeted interventions and early symptom management.

Conclusions

The seriousness of TBI significantly impacts the probability of SI and suicide attempts (SA). Research consistently shows that patients with more severe TBIs tend to have higher rates of SI and SA. Psychological disorders, such as depression and substance abuse disorders, greatly increase the likelihood of suicidal actions after a TBI. These conditions not only raise the occurrence of SI but also lead to earlier and more regular SA.

Assessing the psychometric properties of the Army STARRS' vertical unit cohesion scale: A large-scale, longitudinal study

Unit cohesion is the extent to which military service members feel committed to and supported by their military unit or, conversely, feel overlooked, neglected, and/or alienated. Unit cohesion reflects an important aspect of military social support and can act as a protective factor against mental health challenges, particularly in challenging situations. Theoretical suppositions and emerging evidence suggest that different types of unit support, specifically, vertical unit cohesion and horizontal unit cohesion, uniquely matter for service member well-being. Vertical unit cohesion (support from leaders in the unit and other higher-ranking positions) may be of universal importance to service members with implications for career progression and personal wellbeing, while horizontal unit cohesion (support from fellow unit members and peers) may be of importance under certain circumstances. Informed by the psychometric theory of scale development and validation, the dimensionality of unit cohesion theory, and the need for brief, sound measurement tools, this study first examined the psychometric properties of the Army STARRS four-item Vertical Unit Cohesion Scale in a longitudinal analysis with a large, diverse sample of Soldiers from the Pre/Post Deployment Study component of the Army STARRS dataset (N = 10,116). Then, exploratory analyses were conducted to examine the properties of the Horizontal Unit Cohesion Scale and understand the relationship between vertical and horizontal unit cohesion. Strong evidence for the Vertical Unit Cohesion Scale's psychometric soundness was established regarding factor structure, measurement invariance overtime, and construct validity. Conversely, preliminary evidence suggests that the three-item measure of Horizontal Unit Cohesion should be used with caution. Implications for researchers and military leadership are provided.

Suicidal behavior across a broad range of psychiatric disorders

Suicide is a leading cause of death worldwide. In 2020, some 12.2 million Americans seriously contemplated suicide, 3.2 million planned suicide attempts, and 1.2 million attempted suicide. Traditionally, the approach to treating suicidal behavior (SB) has been to treat the "underlying" psychiatric disorder. However, the number of diagnoses associated with SB is considerable. We could find no studies describing the range of disorders reported to be comorbid with SB. This narrative review summarizes literature documenting the occurrence of SB across the lifespan and the full range of psychiatric diagnoses, not only BPD and those that comprise MDE, It also describes the relevance of these observations to clinical practice, research, and nosology. The literature searches contained the terms "suicid*" and each individual psychiatric diagnosis and identified 587 studies. We did not include case reports, case series, studies only addressing suicidal ideation or non-suicidal self-injury (NSSI), studies on self-harm, not distinguishing between SB and NSSI and studies that did not include any individuals that met criteria for a specific DSM-5 diagnosis (n = 366). We found that SB (suicide and/or suicide attempt) was reported to be associated with 72 out of 145 diagnoses, although data quality varied. Thus, SB is not exclusively germane to Major Depressive Episode (MDE) and Borderline Personality Disorder (BPD), the only conditions for which it is a diagnostic criterion. That SB co-occurs with so many diagnoses reinforces the need to assess current and past SB regardless of diagnosis, and supports the addition of charting codes to the DSM-5 to indicate current or past SB. It also comports with new data that specific genes are associated with SB independent of psychiatric diagnoses, and suggests that SB should be managed with specific suicide prevention interventions in addition to treatments indicated for co-occurring diagnoses. SB diagnostic codes would help researchers and clinicians document and measure SB's trajectory and response to treatment over time, and, ultimately, help develop secondary and tertiary prevention strategies. As a separate diagnosis, SB would preclude situations in which a potentially life-threatening behavior is not accounted for by a diagnosis, a problem that is particularly salient when no mental disorder is present, as is sometimes the case.

Prospective Association of Unmet Mental Health Treatment Needs With Suicidal Behavior Among Combat-Deployed Soldiers

OBJECTIVE

Military personnel frequently report discontinuing or not pursuing psychiatric treatment despite perceiving a need for services. This study aimed to examine how unmet need for treatment or support among U.S. Army soldiers relates to future suicidal ideation (SI) or suicide attempt (SA).

METHODS

Mental health treatment need and help seeking in the past 12 months were evaluated for soldiers (N=4,645) who subsequently deployed to Afghanistan. Weighted logistic regression models were used to examine the prospective association of predeployment treatment needs with SI and SA during and after deployment, with adjustment for potential confounders.

RESULTS

Compared with soldiers without predeployment treatment needs, those who reported not seeking help despite needing it had increased risk for SI during deployment (adjusted OR [AOR]=1.73), past-30-day SI at 2-3 months postdeployment (AOR=2.08), past-30-day SI at 8-9 months postdeployment (AOR=2.01), and SA through 8-9 months postdeployment (AOR=3.65). Soldiers who sought help and stopped treatment without improvement had elevated SI risk at 2-3 months postdeployment (AOR=2.35). Those who sought help and stopped after improving did not have increased SI risk during or 2-3 months after deployment but had elevated risks for SI (AOR=1.71) and SA (AOR=3.43) by 8-9 months postdeployment. Risks for all suicidality outcomes were also elevated among soldiers who reported receiving ongoing treatment before deployment.

CONCLUSIONS

Unmet or ongoing needs for mental health treatment or support before deployment are associated with increased risk for suicidal behavior during and after deployment. Detecting and addressing treatment needs among soldiers before deployment may help prevent suicidality during deployment and reintegration periods.

Double Blast Wave Primary Effect on Synaptic, Glymphatic, Myelin, Neuronal and Neurovascular Markers

Explosive blasts are associated with neurological consequences as a result of blast waves impact on the brain. Yet, the neuropathologic and molecular consequences due to blast waves vs. blunt-TBI are not fully understood. An explosive-driven blast-generating system was used to reproduce blast wave exposure and examine pathological and molecular changes generated by primary wave effects of blast exposure. We assessed if pre- and post-synaptic (synaptophysin, PSD-95, spinophilin, GAP-43), neuronal (NF-L), glymphatic (LYVE1, podoplanin), myelin (MBP), neurovascular (AQP4, S100β, PDGF) and genomic (DNA polymerase-β, RNA polymerase II) markers could be altered across different brain regions of double blast vs. sham animals. Twelve male rats exposed to two consecutive blasts were compared to 12 control/sham rats. Western blot, ELISA, and immunofluorescence analyses were performed across the frontal cortex, hippocampus, cerebellum, and brainstem. The results showed altered levels of AQP4, S100β, DNA-polymerase-β, PDGF, synaptophysin and PSD-95 in double blast vs. sham animals in most of the examined regions. These data indicate that blast-generated changes are preferentially associated with neurovascular, glymphatic, and DNA repair markers, especially in the brainstem. Moreover, these changes were not accompanied by behavioral changes and corroborate the hypothesis for which an asymptomatic altered status is caused by repeated blast exposures.

Participation Mediates the Relationship Between Postconcussive Symptoms and Suicidal Ideation Among Veterans

IMPORTANCE

Veterans with mild traumatic brain injury (mTBI) and associated symptoms are at risk for suicide. Postconcussive symptoms (PCS) may heighten risk for suicidal thoughts by limiting veterans' participation.

OBJECTIVE

To investigate whether participation mediates the relationship between PCS and suicidal ideation.

DESIGN

Cross-sectional, exploratory design. Structural equation models were used to investigate whether participation mediated the relationship between PCS and suicidal ideation.

SETTING

Community.

PARTICIPANTS

Veterans with mTBI (N = 145).

OUTCOMES AND MEASURES

The Ohio State University TBI Identification Method was used to establish mTBI diagnosis. We identified latent variables for PCS and participation using the Neurobehavioral Symptom Inventory and select domains of the Medical Outcomes Study Short Form-36, respectively. We used the Beck Scale for Suicide Ideation to measure the presence of suicidal ideation.

RESULTS

Participation mediated the relationship between PCS and the presence of suicidal ideation (odds ratio [OR] = 1.09, p = .011). More severe PCS were associated with lesser participation (β = -.86, p < .001); greater participation was associated with lower odds of suicidal ideation (OR = 0.92, p = .007).

CONCLUSIONS AND RELEVANCE

PCS may heighten risk for suicidal thoughts among veterans by limiting successful participation, a primary target of occupational therapy intervention. Thus, the results suggest that occupational therapy practitioners can play a substantial role in suicide prevention services for veterans with mTBI. Preventive services could mitigate suicide risk among veterans with mTBI by enabling sustained engagement in meaningful and health-promoting activity (e.g., reasons for living) and targeting PCS. What This Article Adds: Researchers have proposed that occupational therapy practitioners can help prevent veteran suicide by supporting their engagement in meaningful, health-promoting activity and by targeting suicide risk factors within their scope of practice. To the best of our knowledge, this is the first study to offer empirical support for such proposed suicide prevention efforts. Although additional research is needed, these results are promising and highlight a distinct role for occupational therapy in suicide prevention.

Prevalence of suicidal ideation and suicide attempt among patients with traumatic brain injury: A meta-analysis

BACKGROUND

Suicidality is common among patients with traumatic brain injury (TBI). This meta-analysis aimed to assess the prevalence of suicidal ideation (SI) and suicide attempt (SA) in TBI patients.

METHODS

Databases including PubMed, Cochrane Library, Embase, CINAHL, Web of Science, PsycINFO, China National Knowledge Infrastructure (CNKI), VIP, WanFang Data, and Chinese Biomedical Literature Database (CBM) were searched for relevant literature from inception to 9th January 2021. Random effects models were used to estimate the prevalence of SI and SA. The methodological quality of the included studies was assessed using the modified Newcastle-Ottawa Scale. Subgroup analysis was performed based on the geographical location of the institutions.

RESULTS

A total of 16 studies involving 1,146,271 patients with TBI were included in our meta-analysis. The prevalence of SI and SA were 19.1% (95% CI 13.6-24.6%) and 2.1% (95% CI 1.8-2.4%), respectively, while the prevalence of SA in Asian and non-Asian countries were 2.0% (95% CI 0.3-3.7%) and 2.0% (95% CI 1.6-2.3%). Meta-regression analyses revealed that the publication year and age were positively associated, while the geographical location of the institution and sample size were negatively associated with the pooled prevalence of SI. On the other hand, the geographical location of the institution, sample size and age were negatively associated with the pooled prevalence of SA.

LIMITATIONS

The overall heterogeneity between studies was high.

CONCLUSION

SI and SA are common among TBI patients. Therefore, targeted preventive measures are paramount to manage TBI-related suicide.

Mental Health Consequences of Traumatic Brain Injury

Traumatic brain injury (TBI) is associated with a host of psychiatric and neurobehavioral problems. As mortality rates have declined for severe TBI, attention has turned to the cognitive, affective, and behavioral sequelae of injuries across the severity spectrum, which are often more disabling than residual physical effects. Moderate and severe TBI can cause personality changes including impulsivity, severe irritability, affective instability, and apathy. Mild TBI, once considered a largely benign phenomenon, is now known to be associated with a range of affective symptoms, with suicidality, and with worsening or new onset of several psychiatric disorders including posttraumatic stress disorder and major depressive disorder. Repetitive head impacts, often in athletic contexts, are now believed to be associated with a number of emotional and behavioral sequelae. The nature and etiology of mental health manifestations of TBI (including a combination of brain dysfunction and psychological trauma and interrelationships between cognitive, affective, and physical symptoms) are complex and have been a focus of recent epidemiological and mechanistic studies. This paper will review the epidemiology of psychiatric and neurobehavioral problems after TBI in military, civilian, and athletic contexts.

Post-traumatic brain injury antithrombin III recovers Morris water maze cognitive performance, improving cued and spatial learning

BACKGROUND

Neuroinflammation and cerebral edema development following severe traumatic brain injury (TBI) affect subsequent cognitive recovery. Independent of its anticoagulant effects, antithrombin III (AT-III) has been shown to block neurovascular inflammation after severe TBI, reduce cerebral endothelial-leukocyte interactions, and decrease blood-brain barrier permeability. We hypothesized that AT-III administration after TBI would improve post-TBI cognitive recovery, specifically enhancing learning, and memory.

METHODS

Fifteen CD1 male mice were randomized to undergo severe TBI (controlled cortical impact [CCI]: velocity, 6 m/s; depth, 1 mm; diameter, 3 mm) or sham craniotomy and received either intravenous AT-III (250 IU/kg) or vehicle (VEH/saline) 15 minutes and 24 hours post-TBI. Animals underwent Morris water maze testing from 6 to 14 days postinjury consisting of cued learning trials (platform visible), spatial learning trials (platform invisible, spatial cues present), and probe (memory) trials (platform removed, spatial cues present). Intergroup differences were assessed by the Kruskal-Wallis test (p < 0.05).

RESULTS

Morris water maze testing demonstrated that cumulative cued learning (overall mean time in seconds to reach the platform on days 6-8) was worst in CCI-VEH animals (26.1 ± 2.4 seconds) compared with CCI-AT-III counterparts (20.3 ± 2.1 seconds, p < 0.01). Cumulative noncued spatial learning was also worst in the CCI-VEH group (23.4 ± 1.8 seconds) but improved with AT-III (17.6 ± 1.5 seconds, p < 0.01). In probe trials, AT-III failed to significantly improve memory ability. Animals that underwent sham craniotomy demonstrated preserved learning and memory compared with all CCI counterparts (p < 0.05).

CONCLUSION

Antithrombin III improves neurocognitive recovery weeks after TBI. This improvement is particularly related to improvement in learning but not memory function. Pharmacologic support of enhanced learning may support new skill acquisition or relearning to improve outcomes after TBI.

LEVEL OF EVIDENCE

Therapeutic/care management, level II.

Antithrombin III ameliorates post-traumatic brain injury cerebral leukocyte mobilization enhancing recovery of blood brain barrier integrity

BACKGROUND

Acute traumatic coagulopathy often accompanies traumatic brain injury (TBI) and may impair cognitive recovery. Antithrombin III (AT-III) reduces the hypercoagulability of TBI. Antithrombin III and heparinoids such as enoxaparin (ENX) demonstrate potent anti-inflammatory activity, reducing organ injury and modulating leukocyte (LEU) activation, independent of their anticoagulant effect. It is unknown what impact AT-III exerts on cerebral LEU activation and blood-brain barrier (BBB) permeability after TBI. We hypothesized that AT-III reduces live microcirculatory LEU-endothelial cell (EC) interactions and leakage at the BBB following TBI.

METHODS

CD1 mice (n = 71) underwent either severe TBI (controlled cortical impact (CCI), 6-m/s velocity, 1-mm depth, and 4-mm diameter) or sham craniotomy and then received either AT-III (250 IU/kg), ENX (1.5 mg/kg), or vehicle (saline) every 24 hours. Forty-eight hours post-TBI, cerebral intravital microscopy visualized in vivo penumbral microvascular LEU-EC interactions and microvascular leakage to assess BBB inflammation/permeability. Body weight loss and the Garcia neurological test (motor, sensory, reflex, balance) served as surrogates of clinical recovery.

RESULTS

Both AT-III and ENX similarly reduced in vivo penumbral LEU rolling and adhesion (p < 0.05). Antithrombin III also reduced live BBB leakage (p < 0.05). Antithrombin III animals demonstrated the least 48-hour body weight loss (8.4 ± 1%) versus controlled cortical impact and vehicle (11.4 ± 0.5%, p < 0.01). Garcia neurological test scores were similar among groups.

CONCLUSION

Antithrombin III reduces post-TBI penumbral LEU-EC interactions in the BBB leading to reduced neuromicrovascular permeability. Antithrombin III further reduced body weight loss compared with no therapy. Further study is needed to determine if these AT-III effects on neuroinflammation affect longer-term neurocognitive recovery after TBI.

Risk Factors for Suicidal Ideation Following Mild Traumatic Brain Injury: A TRACK-TBI Study

OBJECTIVE

To identify risk factors for suicidal ideation (SI) following mild traumatic brain injury (mTBI).

SETTING

Eleven US level 1 trauma centers.

PARTICIPANTS

A total of 1158 emergency department patients with mTBI (Glasgow Coma Scale score = 13-15) enrolled in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study.

DESIGN

Prospective observational study; weights-adjusted multivariable logistic regression models (n's = 727-883) estimated associations of baseline factors and post-TBI symptoms with SI at 2 weeks and 3, 6, and 12 months postinjury.

MAIN MEASURES

Patient Health Questionnaire, Rivermead Post-Concussion Symptoms Questionnaire.

RESULTS

Preinjury psychiatric history predicted SI at all follow-ups (adjusted odds ratios [AORs] = 2.26-6.33, P values <.05) and history of prior TBI predicted SI at 2 weeks (AOR = 2.36, 95% confidence interval [CI] = 1.16-4.81, P = .018), 3 months (AOR = 2.62, 95% CI = 1.33-5.16, P = .005), and 6 months postinjury (AOR = 2.54, 95% CI = 1.19-5.42, P = .016). Adjusting for these baseline factors, post-TBI symptoms were strongly associated with SI at concurrent (AORs = 1.91-2.88 per standard deviation unit increase in Rivermead Post-Concussion Symptoms Questionnaire score; P values <.0005) and subsequent follow-up visits (AORs = 1.68-2.53; P values <.005). Most of the associations between post-TBI symptoms and SI were statistically explained by co-occurring depression.

CONCLUSION

Screening for psychiatric and prior TBI history may help identify patients at risk for SI following mTBI. Awareness of the strong associations of post-TBI symptoms with SI may facilitate interventions to prevent suicide-related outcomes in patients with mTBI.