Examining the Relationship Between Traumatic Brain Injury and Substance Use Outcomes in the Canadian Population

Brain Injury Is Prevalent and Precedes Tobacco Use among Youth and Young Adults Experiencing Homelessness

70%+ of youth and young adults experiencing homelessness (YYEH; 14-24 years old) smoke combustible tobacco. Little is known about the prevalence of acquired brain injury (ABI) among youth and young adult smokers experiencing homelessness (YYSEH) and its impact on tobacco use progression-the aim of our study. Through an interviewer-administered survey, YYSEH were asked about timing of tobacco use; exposure to causes of ABI; including brain oxygen deprivation (BOD; strangulation; accidental; choking games) and blunt force head trauma (BFHT; intentional; shaken violently; accidental); and perpetrators of intentional assault. Participants (n = 96) were on average 22 years old and from populations who experience structural disparities; including those minoritized by race (84.4%) and gender/sexual orientation (26.0%). In total, 87% of participants reported at least one exposure to BFHT and 65% to BOD. Intentional injury was more common than accidental. Furthermore, 60.4% of participants (n = 59) were classified as having ABI using the Brain Injury Severity Assessment. A significant proportion of YYSEH living with ABI were exposed to both BFHT and BOD prior to trying (68.5%, p = 0.002) and to first regular use (82.8%, p < 0.001) of tobacco. Among YYSEH with ABI; injury exposure occurred a median of 1 and 5 years before age of first regular tobacco use, dependent on injury mechanism. ABI from intentional violence is prevalent and precedes tobacco use among YYSEH.

Substance Use and Sports- or Physical Activity-Related Concussions Among High School Students

History of concussion is associated with substance use. Data from the 2017 National Youth Risk Behavior Survey (N = 14,765) were used in this study to examine associations between sports- or physical activity-related concussions and current cigarette, alcohol, and marijuana use among high school students, and whether other factors moderate those associations. In addition to having played on a sports team, potential moderators examined included persistent feelings of sadness or hopelessness, hours of sleep, and serious difficulty concentrating, remembering, or making decisions. The association between sports- or physical activity-related concussions and current cigarette, alcohol, and marijuana use was significant when controlling for sex, grade, and race/ethnicity and the potential moderators with the exception of cigarette smoking while controlling for hours of sleep. Those involved in the care of high school students after a concussion may consider assessing current cigarette, alcohol, and marijuana use.

Endogenous Opioid Dynorphin Is a Potential Link between Traumatic Brain Injury, Chronic Pain, and Substance Use Disorder

Traumatic brain injury (TBI) is a serious public health problem associated with numerous physical and neuropsychiatric comorbidities. Chronic pain is prevalent and interferes with post-injury functioning and quality of life, whereas substance use disorder (SUD) is the third most common neuropsychiatric diagnosis after TBI. Neither of these conditions has a clear mechanistic explanation based on the known pathophysiology of TBI. Dynorphin is an endogenous opioid neuropeptide that is significantly dysregulated after TBI. Both dynorphin and its primary receptor, the ĸ-opioid receptor (KOR), are implicated in the neuropathology of chronic pain and SUD. Here, we review the known roles of dynorphin and KORs in chronic pain and SUDs. We synthesize this information with our current understanding of TBI and highlight potential mechanistic parallels between and across conditions that suggest a role for dynorphin in long-term sequelae after TBI. In pain studies, dynorphin/KOR activation has either antinociceptive or pro-nociceptive effects, and there are similarities between the signaling pathways influenced by dynorphin and those underlying development of chronic pain. Moreover, the dynorphin/KOR system is considered a key regulator of the negative affective state that characterizes drug withdrawal and protracted abstinence in SUD, and molecular and neurochemical changes observed during the development of SUD are mirrored by the pathophysiology of TBI. We conclude by proposing hypotheses and directions for future research aimed at elucidating the potential role of dynorphin/KOR in chronic pain and/or SUD after TBI.

Health Determinants among North Americans Experiencing Homelessness and Traumatic Brain Injury: A Scoping Review

Traumatic brain injury (TBI) in those experiencing homelessness has been described in recent literature as a contributor to increased morbidity, decreased functional independence, and early mortality. In this systematically conducted scoping review, we aimed to better delineate the health determinants—as defined by Health Canada/Centers for Disease Control and Prevention (CDC)—associated with TBI in North Americans experiencing homelessness. BIOSIS, MEDLINE, CINAHL, EMBASE, SCOPUS, and Global Health were searched from inception to December 30, 2020. Gray literature search consisted of relevant meeting proceedings. A two-step process was undertaken, assessing title/abstract and full articles, respectively, based on inclusion/exclusion criteria, leading to the final 20 articles included in the review. Data were abstracted, assessing the aims, literature quality, and bias. Five health determinants displayed strong associations with TBI in those North Americans experiencing homelessness, including male gender, poor physical environment, negative personal health behaviors, adverse childhood experiences (ACEs), and low educational attainment. In those studies displaying a comparator population experiencing homelessness without TBI, the TBI group displayed trends toward increased disparity in Health Canada and CDC defined health determinants. Most studies suffered from moderate limitations. There are associations between male gender, poor physical environment, negative personal health behaviors, ACEs, and limited education in those experiencing homelessness and TBI. The results suggest that those experiencing homelessness with TBI in North America suffer poorer health consequences than those without TBI. Future research on TBI in North Americans experiencing homelessness should focus on health determinants as potential areas for intervention, which may lead to improved outcomes for those experiencing both homelessness and TBI.

Lifetime History of Traumatic Brain Injury and Behavioral Health Problems in a Population-Based Sample

OBJECTIVE

To investigate the relationships between indices of lifetime history of traumatic brain injury (TBI) exposure and measures of behavioral health status among Ohioans.

PARTICIPANTS

A random sample (n = 6996) of Ohioans contacted to complete the 2014 Ohio Behavioral Risk Factors Surveillance System (BRFSS).

DESIGN

A cross-sectional survey.

MAIN MEASURES

The Ohio State University TBI Identification Method adapted for BRFSS module and BRFSS behavioral indicators.

RESULTS

After demographic adjustment, lifetime history of TBI was found to be associated with increased odds of binge drinking, heavy drinking, smoking, a depressive disorder, or mental health not being good (≥2 days and ≥14 days in last 30 days). Mixed findings across behavioral indicators were observed in regard to number and severity of injury. Age at first injury showed no remarkable associations with the behavioral health indicators.

CONCLUSIONS

Ohioans who have sustained at least one TBI with loss of consciousness in their lifetime are at increased risk for poor behavioral health, including alcohol misuse, smoking, and depression. The findings underscore the need for community-based mental health treatment programs to screen for TBI history in their intake evaluations, and to train clinicians on the provisions of accommodations for cognitive and behavioral deficits.

Lifetime History of Traumatic Brain Injury With Loss of Consciousness and the Likelihood for Lifetime Depression and Risk Behaviors: 2017 BRFSS North Carolina

OBJECTIVE

Because of the growing concern about the potential effects of traumatic brain injuries (TBIs) on a child's developing brain and the potential impact of lifetime depression and risk behaviors associated with TBI, further exploration is warranted.

SETTING AND PARTICIPANTS

Data (N = 4917) from the 2017 North Carolina Behavioral Risk Factors Surveillance System (BRFSS).

DESIGN

Cross-sectional.

MAIN MEASURES

Examine whether a lifetime history of TBI with loss of consciousness (LOC) or having a history of TBI with LOC prior to 18 years of age was associated with a greater likelihood of lifetime depression, current binge drinking, and current cigarette and e-cigarette smoking.

RESULTS

Respondents with a history of TBI with LOC had 2.1 (95% CI, 1.6-2.8) times higher odds of lifetime depression and 1.7 to 1.8 (95% CI, 1.02-2.97) times higher odds of all risk behaviors than those without a lifetime history of TBI with LOC. There were no statistical differences between age of first TBI with LOC and lifetime depression, binge drinking, cigarette smoking, and e-cigarette use after controlling for key demographics.

CONCLUSION

These findings underscore the importance of increasing awareness among healthcare providers of the prevalence of lifetime depression and risk behaviors among individuals with a history of TBI and the need for improved screening and referrals to evidence-based services.

Does a hypoxic injury from a non-fatal overdose lead to an Alzheimer Disease?

Long term consequence of non-fatal overdose in people who use opioids are not well understood. The intermittent exposure to non-fatal overdose leads to a tauopathy that is often accompanied by abrogated neuroprotective response, abnormal amyloid processing and other pathologies. The scope and limitations of available literature are discussed including neuropathologies associated with opioid and overdose exposures, contributing comorbidities and proteinopathies. Contrasting postmortem data of overdose victims with animal models of opioid neuropathologies and hypoxic injury paints a picture distinct from other proteinopathies as well as effects of moderate opioid exposure. Furthermore the reported biochemical changes and potential targets for therapeutic intervention were mapped pointing to underlying imbalance between tau kinases and phosphatases that is characteristic of Alzheimer Disease.

Investigating cannabis use and associated symptoms among university students with and without a history of concussion

Recently, there has been a growing interest in the use of cannabis after traumatic brain injury (TBI); however, little is known about the long-term effects of cannabis on milder injuries and post-concussive symptoms. Further, substance use often increases post-TBI and, thus, individuals who chronically use cannabis may unknowingly be exceeding safe or therapeutic doses. The current cross-sectional study explores the prevalence of cannabis use among university students with and without a history of concussion and examines the relationship between concussion and post-concussive symptoms as a function of cannabis use. Eighty-four undergraduates (n = 51 without a prior concussion; n = 33 with a prior concussion) completed a series of questionnaires, capturing their head injury history, current and past substance use, and post-concussive symptomatology. Results indicated that those with a history of concussion were more likely to use cannabis and had higher cannabis use severity scores compared to those without a previous concussion. Further, among cannabis users only, concussion severity demonstrated a significant positive association with post-concussive symptom (e.g., headaches, memory problems) severity (i.e., frequency, intensity, duration). Taken together, the long-term use of cannabis may be detrimental to individuals with a history of concussion, exacerbating, rather than mitigating, post-concussive symptoms.

Relationship between physical conditions and attempted or completed suicide in more than 9,300 individuals from the United Kingdom: a case-control study

AIMS

The present study of 9,352 adults from the United Kingdom aimed to analyze associations between physical conditions and attempted or completed suicide.

METHODS

This case-control study included patients aged 16-90 years with a first attempted or completed suicide who were followed in general practices in the United Kingdom between January 2008 and December 2017 (index date). Individuals who had not attempted or completed suicide were matched (1:1) to those who had attempted or completed suicide by sex, age, index year, index month, and practice. Variables included sex, age, index year, index month, and all physical and psychiatric conditions diagnosed in more than 1% of patients who had attempted or completed suicide in the year prior to the index date. A multivariable logistic regression analysis was performed to assess possible associations.

RESULTS

The case-control study included 4,676 patients who had and 4,676 patients who had not attempted or completed suicide. After (1:1) matching, 52.1% of the patients were women and the mean (standard deviation) age was 33.6 (15.1) years. After adjusting for psychiatric conditions, we found that three past-year physical conditions were significantly associated with attempted or completed suicide. These conditions were unspecified injuries to the head (odds ratio [OR]=4.26, 95% confidence interval [CI]=2.27-8.00), sleep disorders (OR=1.60, 95% CI=1.09-2.32), and epilepsy (OR=1.57, 95% CI=1.04-2.39).

CONCLUSIONS

Head injuries, sleep disorders, and epilepsy were associated with attempted or completed suicide. Further research is needed to gain a better understanding of the mechanisms underlying these relationships.

Substance use on admission toxicology screen is associated with peri-injury factors and six-month outcome after traumatic brain injury: A TRACK-TBI Pilot study

Substance use is commonly associated with traumatic brain injury (TBI). We investigate associations between active substance use, peri-injury factors, and outcome after TBI across three U.S. Level I trauma centers. TBI subjects from the prospective Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) with Marshall computed tomography (CT) score 1-3, no neurosurgical procedure/operation, and admission urine toxicology screen (tox+/-) were extracted. Associations between tox+/-, comorbidities, hospital variables, and six-month functional (GOSE) and neuropsychiatric (PCL-C, BSI18, RPQ-13, SWLS) outcomes were analyzed. Multivariable regression was performed for associations significant on univariate analysis with odds ratios (mOR) presented. Significance assessed at p < 0.05. In 133 subjects, tox+/tox- were 29.1%/72.9%. Tox+ was younger (35.5/43.6-years, p = 0.018), trended toward male sex (80.6%/63.9%, p = 0.067), was associated with history of seizures (27.8%/10.3%, p = 0.012), self-reported substance use (44.4%/17.5%, p = 0.001), prior TBI (58.8%/34.1%, p = 0.009), GCS < 15 (69.4%/48.4%, p = 0.031) and blood alcohol level >0.08-mg/dl (55.6%/30.8%, p = 0.022). In CT-negative subjects, tox+ was associated with increased hospital admission (95.7%/66.7%, p = 0.034). At six-months, tox+ was associated with screening positive for post-traumatic stress disorder (PCL-C: 40.0%/15.9%; mOR = 8.24, p = 0.022) and psychiatric symptoms (BSI18: 40.0%/14.3%, mOR = 11.06, p = 0.023). Active substance use in TBI may confound GCS assessment, triage to higher level of care, and be associated with increased six-month neuropsychiatric symptoms. Substance use screening should be integrated into standard emergency/acute care TBI protocols to optimize management and resource utilization. Clinicians should be vigilant in providing education, counselling, and follow-up for TBI patients with substance use.

Exploring Traumatic Brain Injuries and Aggressive Antisocial Behaviors in Young Male Violent Offenders

Background: Traumatic brain injury (TBI) is a major cause of disabilities and mortality worldwide, with higher prevalence in offender populations than in the general population. Previous research has strongly advocated increased awareness of TBI in offender populations. The aim of this study was to explore the prevalence and characteristics of TBI, and to investigate associations and interactions between TBI, aggressive antisocial behaviors, general intellectual functioning, and substance use disorders (SUD) in a well-characterized group of young violent offenders. Methods: The study investigated a cohort (n = 269) of 18 to 25-year-old male violent offenders in Sweden. Data on TBI (files + self-report), aggressive antisocial behaviors (Life History of Aggression), SUD (clinical interviews), and general intellectual functioning (General Ability Index, Wechsler Adult Intelligence Scales Third Edition) were collected between 2010 and 2012. Parametric (Student's t-test) and non-parametric (Mann-Whitney U-test, Spearman's rho, χ², Kruskal Wallis test) inferential statistics were applied and effect sizes reported. Results: TBI, both with and without loss of consciousness, was common, with 77.5% of the offenders reporting having suffered at least one TBI during their lifetime. TBI was associated with an increased occurrence of aggressive antisocial behaviors and SUD, and offenders with both TBI and SUD evidenced the largest amount of aggressive antisocial behaviors. No clinically meaningful associations were found between TBI and general intelligence. Effect sizes were in the small to medium range. Conclusions: Our study confirms an increased prevalence of TBI among young violent offenders compared to the general population, as well as associations between TBI, aggressive antisocial behaviors, and SUD. However, it provides no information on the severity of the TBI, nor on the causality of the demonstrated associations. Nevertheless, TBI, and possible related deficits, need to be considered in the assessment and treatment of young violent offenders.

Cannabis in the Treatment of Traumatic Brain Injury: A Primer for Clinicians

Our clinical experience at a specialized brain injury clinic suggests that numerous patients with traumatic brain injury (TBI) are using cannabis to alleviate their symptoms. While this patient population often inquires about the evidence of using cannabis post-head injury for the neurosensory, neurocognitive, and neuropsychiatric sequelae, most health professionals have little to no knowledge of this evidence. Given the recent legalization of recreational cannabis in Canada, questions and guidance related to cannabis use following a TBI are likely to become more common. This article reviews the evidence for cannabis use in psychiatric disorders with or without TBI. Overall, we found that the evidence for the use of cannabis among TBI patients is sparse and that patients tend to have little knowledge of the proven benefits and diverse effects of cannabis use. We feel this paper can serve as a stepping stone for future studies that explore the impact of cannabis use in a TBI population and can guide clinicians in advising their patients.

Traumatic brain injury as an independent risk factor for problem gambling: a matched case-control study

PURPOSE

To assess whether traumatic brain injury (TBI) increases the risks of subsequent problem gambling.

METHODS

We conducted a matched case-control analysis of adults in Ontario, Canada. The study included those who self-reported their gambling activities in the Canadian Community Health Survey 2007-2008. Using Problem Gambling Severity Index, we defined cases as those who were problem gamblers and controls who were recreational gamblers. Cases were matched to controls 1:2 using propensity scores based on demographics, prior mental health, and self-reported behaviours. The main predictor was prior TBI defined as requiring emergency care and identified using ICD-10 codes from administrative health databases. We estimated the likelihood of prior TBI in problem gamblers compared to controls using conditional logistic regression.

RESULTS

Of 30,652 survey participants, 16,002 (53%) reported gambling activity of whom 14,910 (49%) were recreational gamblers and 4% (n = 1092) were problem gamblers. A total of 1469 respondents (5%) had a prior TBI. Propensity score matching yielded 2038 matched pairs with 1019 cases matched to 2037 controls. Case-control analysis showed a significant association between prior TBI and subsequent problem gambling (odds ratio 1.27, 95% confidence interval 1.07-1.51, P = 0.007). The increased risk was mostly apparent in men aged 35 to 64 years who reported alcohol use or smoking. The relative risk of problem gambling in those with two or more TBIs equated to an odds ratio of 2.04 (95% confidence interval 1.05-3.99).

CONCLUSIONS

We found that a prior TBI was associated with an increased subsequent risk of problem gambling. Our findings support more awareness, screening, and treating problem gambling risks among TBI patients.

Selective activation of cannabinoid receptor-2 reduces neuroinflammation after traumatic brain injury via alternative macrophage polarization

Inflammation is an important mediator of secondary neurological injury after traumatic brain injury (TBI). Endocannabinoids, endogenously produced arachidonate based lipids, have recently emerged as powerful anti-inflammatory compounds, yet the molecular and cellular mechanisms underlying these effects are poorly defined. Endocannabinoids are physiological ligands for two known cannabinoid receptors, CB1R and CB2R. In the present study, we hypothesized that selective activation of CB2R attenuates neuroinflammation and reduces neurovascular injury after TBI. Using a murine controlled cortical impact (CCI) model of TBI, we observed a dramatic upregulation of CB2R within infiltrating myeloid cells beginning at 72 h. Administration of the selective CB2R agonist, GP1a (1-5 mg/kg), attenuated pro-inflammatory M1 macrophage polarization, increased anti-inflammatory M2 polarization, reduced edema development, enhanced cerebral blood flow, and improved neurobehavioral outcomes after TBI. In contrast, the CB2R antagonist, AM630, worsened outcomes. Taken together, our findings support the development of selective CB2R agonists as a therapeutic strategy to improve TBI outcomes while avoiding the psychoactive effects of CB1R activation.