Heavy episodic drinking in adolescence and alcohol-related problems in adulthood: A developmental approach to alcohol use across the life course

Heavy episodic drinking (HED) is a major public health concern, and youth who engage in HED are at increased risk for alcohol-related problems that continue into adulthood. Importantly, there is heterogeneity in the onset and course of adolescent HED, as youth exhibit different trajectories of initiation and progression into heavy drinking. Much of what is known about the etiology of adolescent HED and alcohol-related problems that persist into adulthood comes from studies of predominantly White, middle-class youth. Because alcohol use and related problems vary by race/ethnicity and socioeconomic status, it is unclear whether previous findings are relevant for understanding developmental antecedents and distal consequences of adolescent HED for minoritized individuals. In the current study, we utilize a developmental psychopathology perspective to fill this gap in the literature. Using a racially and economically diverse cohort followed from adolescence well into adulthood, we apply group-based trajectory modeling (GBTM) to identify patterns of involvement in HED from age 14 to 17 years. We then investigate developmental antecedents of GBTM class membership, and alcohol-related distal outcomes in adulthood (∼ age 31 years) associated with GBTM class membership. Results highlight the importance of adolescent alcohol use in predicting future alcohol use in adulthood.

Early onset adolescent binge drinking is associated with reduced white matter integrity in post-9/11 adult veterans

Adolescence represents a critical period of neural development during which binge drinking (BD) is prevalent. Though prior work has shown that white matter (WM) integrity is susceptible to damage from excessive alcohol intake in adults, the effect of early adolescent BD on WM health in adulthood remains unknown. Veterans with a history of BD onset before age 15 [n = 49; mean age = 31.8 years; early-onset adolescent binge drinkers (EBD)] and after age 15 [n = 290; mean age = 32.2 years; late-onset adolescent binge drinkers (LBD)] were studied with diffusion tensor imaging. Group differences in fractional anisotropy (FA; movement of water molecules along the WM) and mean diffusivity (MD; average movement of water molecules) were examined as indices of WM integrity using FreeSurfer and FMRIB Software Library (FSL) processing streams. Lower FA and higher MD are thought to represent degradations in WM integrity. A reference group (RG) of social drinkers with no history of BD (n = 31) was used to provide comparative normative data. We observed widespread decreased FA and increased MD in EBDs, compared to LBDs, as well as decreased FA in the pars triangularis, lateral orbitofrontal cortex, superior frontal cortex, isthmus cingulate, and genu and splenium of the corpus callosum EBDs also had lower WM integrity compared to the RG. Adults who initiated BD during early adolescence demonstrated decreased FA and increased MD throughout the frontostriatal circuits that mediate inhibitory control and thus may result in impulsive behavior and a predisposition for developing alcohol use disorder during adulthood.

Diagnostic Accuracy of the Boston Assessment of Traumatic Brain Injury-Lifetime Clinical Interview Compared to Department of Defense Medical Records

INTRODUCTION

Since 2006, efforts have been made to increase the accurate identification of traumatic brain injuries (TBIs) in post-9/11 military personnel. The Boston Assessment of TBI-Lifetime (BAT-L) is the first validated instrument designed specifically to diagnose TBIs throughout the life span in post-9/11 Veterans. The objective was to compare the diagnostic accuracy of the BAT-L with medical records from the Department of Defense (DoD).

MATERIAL AND METHODS

Traumatic brain injury diagnosis for 153 Veterans deployed in 2011 enrolled in the Translational Research Center for TBI and Stress Disorder longitudinal cohort study from the BAT-L clinical interview was compared to DoD online medical records to determine diagnostic prevalence and injury severity for all head injury cases during deployment. Sensitivity, specificity, Cohen's kappa, and Kendall's tau-b were calculated for TBI diagnosis and severity. Concordant TBI cases and discordant TBI cases were compared using chi-square and t-test analyses. This study has been approved by VA Boston by Institutional Review Boards for human participants' protection.

RESULTS

Correspondence of TBI diagnoses from the BAT-L with DoD records was fair (κ = 0.42; sensitivity = 72.7%; specificity = 82.8%). Comparison of injury severity also showed fair correspondence (κ = 0.41). Missing TBI diagnostic data from DoD records were frequent; 43% of TBIs reported on the BAT-L did not have any documentation of assessment or diagnoses in DoD records.

CONCLUSION

This study addresses a critical gap in research by comparing the diagnostic accuracy of a validated, semi-structured clinical interview with available medical records. Diagnosis of TBIs via the BAT-L was both sensitive and specific when compared to DoD records, supporting the validity of the BAT-L for retrospective assessment of military TBI. However, diagnostic correspondence was only fair. This lack of diagnostic agreement was related to multiple factors including lack of documentation at the time of injury by DoD, differences in assessment and goals, and other combat-related motivational factors associated with failure to report injuries while deployed. Several policies have been implemented to address underreporting and under-documentation of TBIs, yet challenges remain. Recommendations for evaluating TBI are presented. Accurate diagnosis of TBI is necessary for appropriate treatment planning, as well as service-related compensation.

Consequences of adolescent drug use

Substance use in adolescence is a known risk factor for the development of neuropsychiatric and substance use disorders in adulthood. This is in part due to the fact that critical aspects of brain development occur during adolescence, which can be altered by drug use. Despite concerted efforts to educate youth about the potential negative consequences of substance use, initiation remains common amongst adolescents world-wide. Additionally, though there has been substantial research on the topic, many questions remain about the predictors and the consequences of adolescent drug use. In the following review, we will highlight some of the most recent literature on the neurobiological and behavioral effects of adolescent drug use in rodents, non-human primates, and humans, with a specific focus on alcohol, cannabis, nicotine, and the interactions between these substances. Overall, consumption of these substances during adolescence can produce long-lasting changes across a variety of structures and networks which can have enduring effects on behavior, emotion, and cognition.

Social stress under binge-like alcohol withdrawal in adolescence: evidence of cannabidiol effect on maladaptive plasticity in rats

BACKGROUND

Alcohol binge drinking may compromise the functioning of the nucleus accumbens (NAc), i.e. the neural hub for processing reward and aversive responses.

METHODS

As socially stressful events pose particular challenges at developmental stages, this research applied the resident-intruder paradigm as a model of social stress, to highlight behavioural neuroendocrine and molecular maladaptive plasticity in rats at withdrawal from binge-like alcohol exposure in adolescence. In search of a rescue agent, cannabidiol (CBD) was selected due to its favourable effects on alcohol- and stress-related harms.

RESULTS

Binge-like alcohol exposed intruder rats displayed a compromised defensive behaviour against the resident and a blunted response of the stress system, in addition to indexes of abnormal dopamine (DA)/glutamate plasticity and dysfunctional spine dynamics in the NAc. CBD administration (60 mg/kg) was able to: (1) increase social exploration in the binge-like alcohol exposed intruder rats, at the expenses of freezing time, and in control rats, which received less aggressive attacks from the resident; (2) reduce corticosterone levels independently on alcohol previous exposure; (3) restore DA transmission and (4) facilitate excitatory postsynaptic strength and remodelling.

CONCLUSIONS

Overall, the maladaptive behavioural and synaptic plasticity promoted by the intersection between binge-like alcohol withdrawal and exposure to adverse social stress can be rescued by a CBD détente effect that results in a successful defensive strategy, supported by a functional endocrine and synaptic plasticity. The current data highlight CBD's relevant therapeutic potential in alcohol- and stress-related harms, and prompt further investigation on its molecular targets.

Adolescent intermittent ethanol exposure enhances adult stress effects in male rats

Binge patterns of alcohol use, prevalent among adolescents, are associated with a higher probability of developing alcohol use disorders (AUD) and other psychiatric disorders, like anxiety and depression. Additionally, adverse life events strongly predict AUD and other psychiatric disorders. As such, the combined fields of stress and AUD have been well established, and animal models indicate that both binge-like alcohol exposure and stress exposure elevate anxiety-like behaviors. However, few have investigated the interaction of adolescent intermittent ethanol (AIE) and adult stressors. We hypothesized that AIE would increase vulnerability to restraint-induced stress (RS), manifested as increased anxiety-like behavior. After AIE exposure, in adulthood, animals were tested on forced swim (FST) and saccharin preference (SP) and then exposed to either RS (90 min/5 days) or home-cage control. Twenty-four hours after the last RS session, animals began testing on the elevated plus maze (EPM), and were re-tested on FST and SP. A separate group of animals were sacrificed in adulthood after AIE and RS, and brains were harvested for immunoblot analysis of dorsal and ventral hippocampus. Consistent with previous reports, AIE had no significant effect on closed arm time in the EPM (anxiety-like behavior). However, in male rats the interaction of AIE and adult RS increased time spent in the closed arms. No effect was observed among female animals. AIE and RS-specific alterations were found in glial and synaptic markers (GLT-1, FMRP and PSD-95) in male animals. These findings indicate AIE has sex-specific effects on both SP and the interaction of AIE and adult RS, which induces a propensity toward anxiety-like behavior in males. Also, AIE produces persistent hippocampal deficits that may interact with adult RS to cause increased anxiety-like behaviors. Understanding the mechanisms behind this AIE-induced increase in stress vulnerability may provide insight into treatment and prevention strategies for alcohol use disorders.

Age of onset of adolescent binge drinking is differentially associated with cortical thickness in post-9/11 adult Veterans

BACKGROUND

Adolescence is a critical period for neural development and has been associated with high rates of alcohol abuse. This research examined potential long-term brain and behavioral effects of early versus late-onset adolescent binge drinking in an adult sample of post-9/11 Veterans.

METHODS

We compared cortical thickness measures in Veterans with a history of binge drinking that began before the age of 15 (n = 50; mean age = 32.1 years) to those with a history of binge drinking with onset after the age of 15 (n = 300; mean age = 32.1 years). Data processing was conducted with FreeSurfer. A targeted neuropsychological battery (Digit Span test, Delis-Kaplan Executive Function System Color-Word Interference Test, California Verbal Learning Test-II) was used to examine the relationships between cortical thickness and attention, memory, and inhibition. A reference group of social drinkers with no history of early binge drinking (n = 31) was used to provide normative data.

RESULTS

Early-onset adolescent binge drinkers (EBD) had greater cortical thickness in several regions than late-onset adolescent binge drinkers (LBD); both binge-drinking groups had greater cortical thickness than the reference group. There was a stronger negative association between cortical thickness and age in EBDs than LBDs in the (i) lateral orbitofrontal cortex, (ii) supramarginal gyrus, (iii) paracentral lobule, and (iv) anterior caudal cingulate. Poorer performance on the attention and inhibition tasks in the EBDs was also associated with thicker cortices.

CONCLUSIONS

This study demonstrates greater cortical thickness across frontoparietal regions in adults who began binge drinking in early versus late adolescence. A stronger negative association between cortical thickness and age in the EBDs suggests that early-onset adolescent binge drinking may be associated with accelerated cortical thinning. Thicker cortex in these regions, which are known to mediate inhibitory control, may increase impulsive behavior and contribute to the risk of alcohol addiction.