Risk profiles for heavy drinking in adolescence: differential effects of gender

Examining Premeditation and Urgency as Moderators of the Longitudinal Association Between Alcohol-Induced Blackouts and AUDIT Scores Among Adolescents and Young Adults

BACKGROUND

Adolescence and young adulthood are developmental periods where both initiation and escalation of alcohol consumption is common. While existing literature highlights the potential role alcohol-induced blackouts (AIBs) may have on the development of alcohol use disorders as well as how impulsivity is associated with alcohol use, research to date has not been conducted within the United States. Therefore, this study aimed to examine longitudinal associations between AIBs and hazardous alcohol use risk (AUDIT) in adolescents and young adults, while exploring the moderating effects of impulsivity facets (i.e., premeditation and urgency).

METHODS

Participants were recruited for a longitudinal ecological momentary assessment (EMA) study in Texas, examining cognitions and alcohol use. The analytical sample comprised 556 participants (58.6% female, 70.8% White, Mage = 21.5, SD = 2.5). Data were collected at baseline and a 12-month follow-up.

RESULTS

Utilizing generalized linear regression models, results revealed a significant prospective association between AIBs and AUDIT scores. Findings indicated premeditation significantly moderated this association, whereas urgency did not.

CONCLUSION

Targeting prevention programs, particularly toward adolescents and young adults with a history of AIBs, especially those with elevated levels of premeditation, may be effective in mitigating the risk of alcohol use disorder development.

Alcohol Withdrawal Alters the Inhibitory Landscape of the Prelimbic Cortex in an Interneuron- and Sex-specific Manner

Alcohol use disorder (AUD) is highly prevalent and associated with substantial morbidity and high mortality among substance use disorders. While there are currently three FDA-approved medications for treating AUDs, none specifically target the withdrawal/negative affect stage of AUD, underscoring the need to understand the underlying neurobiology during this critical stage of the addiction cycle. One key region involved in alcohol withdrawal and negative affect is the prelimbic cortex, a subregion of the medial prefrontal cortex. While previous studies have examined alcohol-related adaptations in prefrontal cortical principal glutamatergic neurons, here we used male and female PV:Ai14, SOM:Ai14 and VIP:Ai14 mice to examine synaptic adaptations in all three major classes of prelimbic cortex interneurons following 72 hour withdrawal from a continuous access to two bottle choice model of EtOH drinking in male and female mice. We found that alcohol withdrawal increased excitability of prelimbic PV interneurons in males, but decreased excitability in prelimbic VIP interneurons in females. Additionally, alcohol withdrawal reduced GABA release onto PV interneurons in males while increasing glutamate release onto VIP interneurons in females. In SOM interneurons, alcohol withdrawal had no effect on excitability, but decreased glutamate release onto SOM interneurons in males. Together, our studies identified sex-specific alcohol withdrawal-induced synaptic plasticity in three different types of interneurons and could provide insight into the cellular substrates of negative affective states associated with alcohol withdrawal.

Examining associations between brain morphology in late childhood and early alcohol or tobacco use initiation in adolescence: Findings from a large prospective cohort

A prominent challenge in understanding neural consequences of substance use involves disentangling predispositional risk factors from resulting consequences of substance use. Existing literature has identified pre-existing brain variations as vulnerability markers for substance use throughout adolescence. As early initiation of use is an important predictor for later substance use problems, we examined whether pre-existing brain variations are associated with early initiation of use. In the Generation R Study, a prospective population-based cohort, brain morphology (gray matter volume, cortical thickness and surface area) was assessed at ages 10 and 14 using neuroimaging. In the second wave, participants reported on alcohol and tobacco use initiation. From a base study population (N = 3019), we examined the longitudinal (N = 2218) and cross-sectional (N = 1817) association between brain morphology of frontolimbic regions of interest known to be associated with substance use risk, and very early (age < 13) alcohol/tobacco use initiation. Additionally, longitudinal and cross-sectional associations were examined with a brain surface-based approach. Models were adjusted for age at neuroimaging, sex and relevant sociodemographic factors. No associations were found between brain morphology (ages 10 and 14) and early alcohol/tobacco use initiation (<13 years). Sex-specific analyses suggested a cross-sectional association between smaller brain volume and early initiated tobacco use in girls. Our findings are important for interpreting studies examining neural consequences of substance use in the general population. Future longitudinal studies are needed to specify whether these findings can be extended to initiation and continuation of alcohol/tobacco use in later stages of adolescence.

Adolescent substance use initiation and long-term neurobiological outcomes: insights, challenges and opportunities

The increased frequency of risk taking behavior combined with marked neuromaturation has positioned adolescence as a focal point of research into the neural causes and consequences of substance use. However, little work has provided a summary of the links between adolescent initiated substance use and longer-term brain outcomes. Here we review studies exploring the long-term effects of adolescent-initiated substance use with structural and microstructural neuroimaging. A quarter of all studies reviewed conducted repeated neuroimaging assessments. Long-term alcohol use, as well as tobacco use were consistently associated with smaller frontal cortices and altered white matter microstructure. This association was mostly observed in the ACC, insula and subcortical regions in alcohol users, and for the OFC in tobacco users. Long-term cannabis use was mostly related to altered frontal cortices and hippocampal volumes. Interestingly, cannabis users scanned more years after use initiation tended to show smaller measures of these regions, whereas those with fewer years since initiation showed larger measures. Long-term stimulant use tended to show a similar trend as cannabis in terms of years since initiation in measures of the putamen, insula and frontal cortex. Long-term opioid use was mostly associated with smaller subcortical and insular volumes. Of note, null findings were reported in all substance use categories, most often in cannabis use studies. In the context of the large variety in study designs, substance use assessment, methods, and sample characteristics, we provide recommendations on how to interpret these findings, and considerations for future studies.

Mapping the neuroanatomical abnormalities in a phenotype of male compulsive rats

Compulsivity is considered a transdiagnostic dimension in obsessive-compulsive and related disorders, characterized by heterogeneous cognitive and behavioral phenotypes associated with abnormalities in cortico-striatal-thalamic-cortical circuitry. The present study investigated the structural morphology of white and gray matter in rats selected for low- (LD) and high- (HD) compulsive drinking behavior on a schedule-induced polydipsia (SIP) task. Regional brain morphology was assessed using ex-vivo high-resolution magnetic resonance imaging (MRI). Voxel-based morphometry of segmented MRI images revealed larger white matter volumes in anterior commissure and corpus callosum of HD rats compared with LD rats. HD rats also showed significantly larger regional volumes of dorsolateral orbitofrontal cortex, striatum, amygdala, hippocampus, midbrain, sub-thalamic nucleus, and cerebellum. By contrast, the medial prefrontal cortex was significantly smaller in HD rats compared with LD rats with no significant group differences in whole brain, ventricular, or cerebrospinal fluid volumes. These findings show that limbic cortico-basal ganglia structures implicated in impulse control disorders are distinct in rats that are vulnerable to develop compulsive behavior. Such abnormalities may be relevant to the etiology of compulsive disorders in humans.

Associations between alcohol use and sex-specific maturation of subcortical gray matter morphometry from adolescence to adulthood: Replication across two longitudinal samples

Subcortical brain morphometry matures across adolescence and young adulthood, a time when many youth engage in escalating levels of alcohol use. Initial cross-sectional studies have shown alcohol use is associated with altered subcortical morphometry. However, longitudinal evidence of sex-specific neuromaturation and associations with alcohol use remains limited. This project used generalized additive mixed models to examine sex-specific development of subcortical volumes and associations with recent alcohol use, using 7 longitudinal waves (n = 804, 51% female, ages 12-21 at baseline) from the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA). A second, independent, longitudinal dataset, with up to four waves of data (n = 467, 43% female, ages 10-18 at baseline), was used to assess replicability. Significant, replicable non-linear normative volumetric changes with age were evident in the caudate, putamen, thalamus, pallidum, amygdala and hippocampus. Significant, replicable negative associations between subcortical volume and alcohol use were found in the hippocampus in all youth, and the caudate and thalamus in female but not male youth, with significant interactions present in the caudate, thalamus and putamen. Findings suggest a structural vulnerability to alcohol use, or a predisposition to drink alcohol based on brain structure, with female youth potentially showing heightened risk, compared to male youth.

Uncontrolled eating and sensation-seeking partially explain the prediction of future binge drinking from adolescent brain structure

Binge drinking behavior in early adulthood can be predicted from brain structure during early adolescence with an accuracy of above 70%. We investigated whether this accurate prospective prediction of alcohol misuse behavior can be explained by psychometric variables such as personality traits or mental health comorbidities in a data-driven approach. We analyzed a subset of adolescents who did not have any prior binge drinking experience at age 14 (IMAGEN dataset, n = 555, 52.61% female). Participants underwent structural magnetic resonance imaging at age 14, binge drinking assessments at ages 14 and 22, and psychometric questionnaire assessments at ages 14 and 22. We derived structural brain features from T1-weighted magnetic resonance and diffusion tensor imaging. Using Machine Learning (ML), we predicted binge drinking (age 22) from brain structure (age 14) and used counterbalancing with oversampling to systematically control for 110 + variables from a wide range of social, personality, and other psychometric characteristics potentially associated with binge drinking. We evaluated if controlling for any variable resulted in a significant reduction in ML prediction accuracy. Sensation-seeking (-13.98 ± 1.68%), assessed via the Substance Use Risk Profile Scale at age 14, and uncontrolled eating (-13.98 ± 3.28%), assessed via the Three-Factor-Eating-Questionnaire at age 22, led to significant reductions in mean balanced prediction accuracy upon controlling for them. Thus, sensation-seeking and binge eating could partially explain the prediction of future binge drinking from adolescent brain structure. Our findings suggest that binge drinking and binge eating at age 22 share common neurobiological precursors discovered by the ML model. These neurobiological precursors seem to be associated with sensation-seeking at age 14. Our results facilitate early detection of increased risk for binge drinking and inform future clinical research in trans-diagnostic prevention approaches for adolescent alcohol misuse.

Neuroanatomical predictors of problematic alcohol consumption in adolescents: a systematic review of longitudinal studies

AIMS

This study aimed to systematically review the literature on neuroanatomical predictors of future problematic drinking in adolescents.

METHODS

Using PRISMA guidelines, a systematic review was conducted to evaluate neuroanatomical predictors of problematic alcohol consumption in adolescents. EMBASE, MEDLINE, and PsycINFO databases were searched from inception to 6 January 2023. Studies were included if they were original, had a prospective design, had a sample size of at least 12, had a follow-up period of at least 1 year, had at least one structural neuroimaging scan before 18 with no prior alcohol use, and had alcohol use as the primary outcome. Studies were excluded if they had animals only and were not in English. Risk of bias was conducted using the CASP tool.

RESULTS

Out of 1412 studies identified, 19 studies met the criteria, consisting of 11 gray matter (n = 4040), 5 white matter (n = 319), and 3 assessing both (n = 3608). Neuroanatomical predictors of future problematic drinking in adolescents were reported to be distributed across various brain regions such as the orbitofrontal cortex and paralimbic regions. However, the findings were largely heterogeneous.

CONCLUSIONS

This is the first systematic review to map out the existing literature on neuroanatomical predictors of problematic drinking in adolescents. Future research should focus on the aforementioned regions to determine their role in predicting future problematic drinking with more certainty.

Alcohol use and grey matter structure: Disentangling predispositional and causal contributions in human studies

Alcohol use is a growing global health concern and economic burden. Alcohol involvement (i.e., initiation, use, problematic use, alcohol use disorder) has been reliably associated with broad spectrum grey matter differences in cross-sectional studies. These findings have been largely interpreted as reflecting alcohol-induced atrophy. However, emerging data suggest that brain structure differences also represent pre-existing vulnerability factors for alcohol involvement. Here, we review evidence from human studies with designs (i.e., family-based, genomic, longitudinal) that allow them to assess the plausibility that these correlates reflect predispositional risk factors and/or causal consequences of alcohol involvement. These studies provide convergent evidence that grey matter correlates of alcohol involvement largely reflect predisposing risk factors, with some evidence for potential alcohol-induced atrophy. These conclusions highlight the importance of study designs that can provide causal clues to cross-sectional observations. An integrative model may best account for these data, in which predisposition to alcohol use affects brain development, effects which may then be compounded by the neurotoxic consequences of heavy alcohol use.

Testing the consequences of alcohol, cannabis, and nicotine use on hippocampal volume: a quasi-experimental cotwin control analysis of young adult twins

BACKGROUND

Alcohol, cannabis, and nicotine use are highly comorbid and alarmingly prevalent in young adults. The hippocampus may be particularly sensitive to substance exposure. This remains largely untested in humans and familial risk may confound exposure effects. We extend prior work on alcohol and hippocampal volume in women by testing common and unique substance use effects and the potential moderating role of sex on hippocampal volume during emerging adulthood. A quasi-experimental cotwin control (CTC) design was used to separate familial risk from exposure consequences.

METHODS

In a population-based sample of 435 24-year-old same-sex twins (58% women), dimensional measures (e.g. frequency, amount) of alcohol, cannabis, and nicotine use across emerging adulthood were assessed. Hippocampal volume was assessed using MRI.

RESULTS

Greater substance use was significantly associated with lower hippocampal volume for women but not men. The same pattern was observed for alcohol, cannabis, and nicotine. CTC analyses provided evidence that hippocampal effects likely reflected familial risk and the consequence of substance use in general and alcohol and nicotine in particular; cannabis effects were in the expected direction but not significant. Within-pair mediation analyses suggested that the effect of alcohol use on the hippocampus may reflect, in part, comorbid nicotine use.

CONCLUSIONS

The observed hippocampal volume deviations in women likely reflected substance-related premorbid familial risk and the consequences of smoking and, to a lesser degree, drinking. Findings contribute to a growing body of work suggesting heightened risk among women toward experiencing deleterious effects of substance exposure on the still-developing young adult hippocampus.

Brain morphology predictors of alcohol, tobacco, and cannabis use in adolescence: A systematic review

In the last decade, extensive research has emerged on the predictive value of brain morphology for substance use initiation and related problems during adolescence. This systematic review provides an overview of longitudinal studies on pre-existing brain variations and later initiation of alcohol, tobacco, and cannabis use (N = 18). Adolescent structural neuroimaging studies that started before substance use initiation suggest that a smaller anterior cingulate cortex (ACC) volume, thicker or smaller superior frontal gyrus, and larger nucleus accumbens (NAcc) volume are associated with future alcohol use. Also, both smaller and larger orbitofrontal cortex (OFC) volumes were associated with future cannabis and combined alcohol/cannabis use. Smaller amygdala volumes were related to future daily tobacco smoking. These findings could point to specific vulnerabilities for adolescent substance use, as these brain areas are involved in cognitive control (ACC), reward (NAcc), motivation (OFC), and emotional memory (amygdala). However, the reported findings were inconsistent in directionality and laterality, and the largest study on alcohol use predictors reported null findings. Therefore, large population-based longitudinal studies should investigate the robustness and mechanisms of these associations. We suggested future research directions regarding sample selection, timing of baseline and follow-up measurements, and a harmonization approach of study methods.

Alcohol's effects on the mouse brain are modulated by age and sex

Binge alcohol consumption is common among adolescents and may impair normal brain development. Emerging, longitudinal studies in adolescents suggest that the effects of binge alcohol exposure on brain structure differ between sexes. To test the hypothesis that the effects of binge alcohol exposure on developmental brain growth trajectories are influenced by age of exposure and sex, adolescent and adult, male and female C57Bl/6 mice (n = 32), were exposed to a binge‐like ethanol (EtOH) exposure paradigm (i.e., 5 cycles of 2 on/2 off days of 5 g/kg EtOH intraperitoneal) or served as saline controls. Longitudinal structural magnetic resonance imaging was acquired at baseline, following binge EtOH exposure, and after 2 weeks of recovery. Alcohol treatment showed interactions with age and sex in altering whole brain volume: adolescents of both sexes demonstrated inhibited whole brain growth relative to their control counterparts, although significance was only attained in female mice which showed a larger magnitude response to EtOH compared to male mice. In region of interest analyses, the somatosensory cortex and cerebellum showed inhibited growth in male and female adolescent mice exposed to EtOH, but the difference relative to controls did not reach multiple comparison‐corrected statistical significance. These data suggest that in mice exposed to binge EtOH treatment, adolescent age of exposure and female sex may confer a higher risk to the detrimental effects of EtOH on brain structure and reinforce the need for direct testing of both sexes.

The Differential Effects of Chronic Alcohol and Cigarette Smoke Exposures on Cognitive-Behavioral Dysfunction in Long Evans Rats

Background and Objective

Chronic heavy alcohol consumption and daily cigarette smoking are the most prevalent substance use problems in the U.S., including Veterans. Excessive alcohol use causes neurocognitive and behavioral deficits that can be linked to neurodegeneration. Similarly, preclinical and clinical data suggest that smoking also leads to brain atrophy. This study examines the differential and additive effects of alcohol and cigarette smoke (CS) exposures on cognitive-behavioral function.

Methods

A 4-way experimental model of chronic alcohol and CS exposures was generated using 4-week-old male and female Long Evans rats that were pair-fed with Lieber-deCarli isocaloric liquid diets containing 0% or 24% ethanol for 9 weeks. Half of the rats in the control and ethanol groups were exposed to CS for 4 hours/day and 4 days/week for 9 weeks. All rats were subjected to Morris Water Maze, Open Field, and Novel Object Recognition testing in the last experimental week.

Results

Chronic alcohol exposure impaired spatial learning as shown by significantly increased latency to locate the platform, and it caused anxiety-like behavior marked by the significantly reduced percentage of entries to the center of the arena. Chronic CS exposure impaired recognition memory as suggested by significantly less time spent at the novel object. Combined exposures to alcohol and CS did not show any significant additive or interactive effect on cognitive-behavioral function.

Conclusion

Chronic alcohol exposure was the main driver of spatial learning, while the effect of secondhand CS exposure was not robust. Future studies need to mimic direct CS exposure effects in humans.

The prediction of resilience to alcohol consumption in youths: insular and subcallosal cingulate myeloarchitecture

BACKGROUND

The prediction of alcohol consumption in youths and particularly biomarkers of resilience, is critical for early intervention to reduce the risk of subsequent harmful alcohol use.

METHODS

At baseline, the longitudinal relaxation rate (R1), indexing grey matter myelination (i.e. myeloarchitecture), was assessed in 86 adolescents/young adults (mean age = 21.76, range: 15.75-26.67 years). The Alcohol Use Disorder Identification Test (AUDIT) was assessed at baseline, 1- and 2-year follow-ups (12- and 24-months post-baseline). We used a whole brain data-driven approach controlled for age, gender, impulsivity and other substance and behavioural addiction measures, such as problematic cannabis use, drug use-related problems, internet gaming, pornography use, binge eating, and levels of externalization, to predict the change in AUDIT scores from R1.

RESULTS

Greater baseline bilateral anterior insular and subcallosal cingulate R1 (cluster-corrected family-wise error p < 0.05) predict a lower risk for harmful alcohol use (measured as a reduction in AUDIT scores) at 2-year follow-up. Control analyses show that other grey matter measures (local volume or fractional anisotropy) did not reveal such an association. An atlas-based machine learning approach further confirms the findings.

CONCLUSIONS

The insula is critically involved in predictive coding of autonomic function relevant to subjective alcohol cue/craving states and risky decision-making processes. The subcallosal cingulate is an essential node underlying emotion regulation and involved in negative emotionality addiction theories. Our findings highlight insular and cingulate myeloarchitecture as a potential protective biomarker that predicts resilience to alcohol misuse in youths, providing novel identifiers for early intervention.

Structural differences in adolescent brains can predict alcohol misuse

Alcohol misuse during adolescence (AAM) has been associated with disruptive development of adolescent brains. In this longitudinal machine learning (ML) study, we could predict AAM significantly from brain structure (T1-weighted imaging and DTI) with accuracies of 73 -78% in the IMAGEN dataset (n∼1182). Our results not only show that structural differences in brain can predict AAM, but also suggests that such differences might precede AAM behavior in the data. We predicted 10 phenotypes of AAM at age 22 using brain MRI features at ages 14, 19, and 22. Binge drinking was found to be the most predictable phenotype. The most informative brain features were located in the ventricular CSF, and in white matter tracts of the corpus callosum, internal capsule, and brain stem. In the cortex, they were spread across the occipital, frontal, and temporal lobes and in the cingulate cortex. We also experimented with four different ML models and several confound control techniques. Support Vector Machine (SVM) with rbf kernel and Gradient Boosting consistently performed better than the linear models, linear SVM and Logistic Regression. Our study also demonstrates how the choice of the predicted phenotype, ML model, and confound correction technique are all crucial decisions in an explorative ML study analyzing psychiatric disorders with small effect sizes such as AAM.

Gender and Childhood Victimization: A Longitudinal Study of Heavy Drinking in Young Adulthood

The present longitudinal study, for 12 years, followed a group of young adults, examining (1) whether/how victimization in childhood increased the likelihood of heavy drinking; (2) whether depression mediated the strain-heavy drinking relationship; and (3) whether/how relationships among strain, depression, and heavy drinking differed across two gender groups. Data came from the National Longitudinal Survey of Youth 1997 cohort, dating 2004-2015 (5 interview waves and 22,549 person-wave measurements total). We linked consumption of 5+ drinks (during the month prior) to four discrete measures of violent victimization, to one measure of stressful events, and to depression. We needed to consider repeat measures of the same variables over time, so we used generalized estimating equations (GEE) to analyze data. Depression was found to increase heavy drinking uniformly. Empirical evidence confirmed that in the strain-heavy drinking relationship, depression plays a minor mediating role. Gender moderated heavy drinking's associations. Specifically, bullying in childhood raised risk for female respondents. The current strain was associated with a higher risk of heavy drinking among male respondents. Childhood victimization, as well as current life stress, play an important role in depression and heavy drinking. Future research should focus on the development of specific, targeted care to reduce heavy drinking's harm and promote equity among Americans.

Hypoactive Thalamic Crh+ Cells in a Female Mouse Model of Alcohol Drinking After Social Trauma

BACKGROUND

Comorbid stress-induced mood and alcohol use disorders are increasingly prevalent among female patients. Stress exposure can disrupt salience processing and goal-directed decision making, contributing to persistent maladaptive behavioral patterns; these and other stress-sensitive cognitive and behavioral processes rely on dynamic and coordinated signaling by midline and intralaminar thalamic nuclei. Considering the role of social trauma in the trajectory of these debilitating psychopathologies, identifying vulnerable thalamic cells may provide guidance for targeting persistent stress-induced symptoms.

METHODS

A novel behavioral protocol traced the progression from social trauma to the development of social defensiveness and chronically escalated alcohol consumption in female mice. Recent cell activation-measured as cFos-was quantified in thalamic cells after safe social interactions, revealing stress-sensitive corticotropin-releasing hormone-expressing (Crh+) anterior central medial thalamic (aCMT) cells. These cells were optogenetically stimulated during stress-induced social defensiveness and abstinence-escalated binge drinking.

RESULTS

Crh+ aCMT neurons exhibited substantial activation after social interactions in stress-naïve but not in stressed female mice. Photoactivating Crh+ aCMT cells dampened stress-induced social deficits, whereas inhibiting these cells increased social defensiveness in stress-naïve mice. Optogenetically activating Crh+ aCMT cells diminished abstinence-escalated binge alcohol drinking in female mice, regardless of stress history.

CONCLUSIONS

This work uncovers a role for Crh+ aCMT neurons in maladaptive stress-induced social interactions and in binge drinking after forced abstinence in female mice. This molecularly defined thalamic cell population may serve as a critical stress-sensitive hub for social deficits caused by exposure to social trauma and for patterns of excessive alcohol drinking in female populations.

The Effects of Alcohol and Cannabis Use on the Cortical Thickness of Cognitive Control and Salience Brain Networks in Emerging Adulthood: A Co-twin Control Study

BACKGROUND

Impairments in inhibitory control and its underlying brain networks (control/salience areas) are associated with substance misuse. Research often assumes a causal substance exposure effect on brain structure. This assumption remains largely untested, and other factors (e.g., familial risk) may confound exposure effects. We leveraged a genetically informative sample of twins aged 24 years and a quasi-experimental co-twin control design to separate alcohol or cannabis exposure effects during emerging adulthood from familial risk on control/salience network cortical thickness.

METHODS

In a population-based sample of 436 twins aged 24 years, dimensional measures of alcohol and cannabis use (e.g., frequency, density, quantity, intoxications) across emerging adulthood were assessed. Cortical thickness of control/salience network areas were assessed using magnetic resonance imaging and defined by a fine-grained cortical atlas.

RESULTS

Greater alcohol, but not cannabis, misuse was associated with reduced thickness of prefrontal (e.g., dorso/ventrolateral, right frontal operculum) and frontal medial cortices, as well as temporal lobe, intraparietal sulcus, insula, parietal operculum, precuneus, and parietal medial areas. Effects were predominately (pre)frontal and right lateralized. Co-twin control analyses suggested that the effects likely reflect both the familial predisposition to misuse alcohol and, specifically for lateral prefrontal, frontal/parietal medial, and right frontal operculum, an alcohol exposure effect.

CONCLUSIONS

This study provides novel evidence that alcohol-related reductions in cortical thickness of control/salience brain networks likely represent the effects of alcohol exposure and premorbid characteristics of the genetic predisposition to misuse alcohol. The dual effects of these two alcohol-related causal influences have important and complementary implications regarding public health and prevention efforts to curb youth drinking.

Neural correlates of cue-induced changes in decision-making distinguish subjects with gambling disorder from healthy controls

In addiction, there are few human studies on the neural basis of cue-induced changes in value-based decision making (Pavlovian-to-instrumental transfer, PIT). It is especially unclear whether neural alterations related to PIT are due to the physiological effects of substance abuse or rather related to learning processes and/or other etiological factors related to addiction. We have thus investigated whether neural activation patterns during a PIT task help to distinguish subjects with gambling disorder (GD), a nonsubstance-based addiction, from healthy controls (HCs). Thirty GD and 30 HC subjects completed an affective decision-making task in a functional magnetic resonance imaging (fMRI) scanner. Gambling-associated and other emotional cues were shown in the background during the task. Data collection and feature modeling focused on a network of nucleus accumbens (NAcc), amygdala, and orbitofrontal cortex (OFC) (derived from PIT and substance use disorder [SUD] studies). We built and tested a linear classifier based on these multivariate neural PIT signatures. GD subjects showed stronger PIT than HC subjects. Classification based on neural PIT signatures yielded a significant area under the receiver operating curve (AUC-ROC) (0.70, p = 0.013). GD subjects showed stronger PIT-related functional connectivity between NAcc and amygdala elicited by gambling cues, as well as between amygdala and OFC elicited by negative and positive cues. HC and GD subjects were thus distinguishable by PIT-related neural signatures including amygdala-NAcc-OFC functional connectivity. Neural PIT alterations in addictive disorders might not depend on the physiological effect of a substance of abuse but on related learning processes or even innate neural traits.

Promising vulnerability markers of substance use and misuse: A review of human neurobehavioral studies

Substance use often begins, and noticeably escalates, during adolescence. Identifying predictive neurobehavioral vulnerability markers of substance use and related problems may improve targeted prevention and early intervention initiatives. This review synthesizes 44 longitudinal studies and explores the utility of developmental imbalance models and neurobehavioral addiction frameworks in predicting neural and cognitive patterns that are associated with prospective substance use initiation and escalation among young people. A total of 234 effect sizes were calculated and compared. Findings suggest that aberrant neural structure and function of regions implicated in reward processing, cognitive control, and impulsivity can predate substance use initiation, escalation, and disorder. Functional vulnerability markers of substance use include hyperactivation during reward feedback and risk evaluation in prefrontal and ventral striatal regions, fronto-parietal hypoactivation during working memory, distinctive neural patterns during successful (fronto-parietal hyperactivation) and failed response inhibition (frontal hypoactivation), and related cognitive deficits. Structurally, smaller fronto-parietal and amygdala volume and larger ventral striatal volume predicts prospective substance misuse. Taken together, the findings of this review suggest that neurobehavioral data can be useful in predicting future substance use behaviors. Notably, little to no research has empirically tested the underlying assumptions of widely used theoretical frameworks. To improve the reliability and utility of neurobehavioral data in predicting future substance use behaviors, recommendations for future research are provided. This article is part of the special issue on 'Vulnerabilities to Substance Abuse.'

Cue-induced effects on decision-making distinguish subjects with gambling disorder from healthy controls

While an increased impact of cues on decision-making has been associated with substance dependence, it is yet unclear whether this is also a phenotype of non-substance-related addictive disorders, such as gambling disorder (GD). To better understand the basic mechanisms of impaired decision-making in addiction, we investigated whether cue-induced changes in decision-making could distinguish GD from healthy control (HC) subjects. We expected that cue-induced changes in gamble acceptance and specifically in loss aversion would distinguish GD from HC subjects. Thirty GD subjects and 30 matched HC subjects completed a mixed gambles task where gambling and other emotional cues were shown in the background. We used machine learning to carve out the importance of cue dependency of decision-making and of loss aversion for distinguishing GD from HC subjects. Cross-validated classification yielded an area under the receiver operating curve (AUC-ROC) of 68.9% (p = .002). Applying the classifier to an independent sample yielded an AUC-ROC of 65.0% (p = .047). As expected, the classifier used cue-induced changes in gamble acceptance to distinguish GD from HC. Especially, increased gambling during the presentation of gambling cues characterized GD subjects. However, cue-induced changes in loss aversion were irrelevant for distinguishing GD from HC subjects. To our knowledge, this is the first study to investigate the classificatory power of addiction-relevant behavioral task parameters when distinguishing GD from HC subjects. The results indicate that cue-induced changes in decision-making are a characteristic feature of addictive disorders, independent of a substance of abuse.

(Neuro)therapeutic Approaches in the Field of Alcohol Use Disorders

Purpose of Review

Alcohol use disorder (AUD) is a burdening chronic condition that is characterized by high relapse rates despite severe negative consequences. There has been a recent emergence of interest in (neuro)therapeutic intervention strategies that largely involve the detrimental change in mechanisms linked to addiction disorders. Most prominently, the latter include habitual decision-making, cue-induced behavioral tendencies, as well as the amplifying effects of stressful events on drinking behavior. This article discusses these learning mechanisms and modification thereof as possible targets of (neuro)therapeutic interventions for AUD.

Recent Findings

Psychological therapies that target dysregulated neurocognitive processes underlying addictive behavior may hold promise as effective treatments for AUD.

Summary

Despite the progression in psychological and neuroscience research in the field of AUD, many behavioral interventions fail to systematically integrate and apply such findings into treatment development. Future research should focus on the targeted modification of the aforementioned processes.

Alcohol Screening, Brief Intervention, and Referral to Treatment (SBIRT) for Girls and Women

Females ages 12 and older are the fastest growing segment of alcohol consumers in the United States, with the past decade showing a 16% increase in alcohol use per 12-month period and a 58% increase in high-risk drinking (i.e., > 3 drinks in a day and/or > 7 drinks in a week) per 12-month period. The increase in alcohol use and risk drinking poses unique and serious consequences for women. Women have a more rapid progression to alcohol-related problems and alcohol use disorders (AUD) than men, and if pregnant, women can potentially expose the fetus to alcohol. Screening, brief intervention, and referral to treatment (SBIRT) is an evidence-based, integrated public health approach used to identify and address risky alcohol use among women in a variety of health and social service settings. This article presents the current status of SBIRT among girls ages 12 and older, women of childbearing age, and older women. Screening instruments, brief interventions, and implementation issues specific to women of all ages are described. Through this review of the current literature, care providers can determine best practices for the prevention and treatment of risk drinking in women of all ages presenting in health care settings.

Effects of an Orexin-2 Receptor Antagonist on Sleep and Event-Related Oscillations in Female Rats Exposed to Chronic Intermittent Ethanol During Adolescence

BACKGROUND

Alcohol use is on the rise among women in the United States which is especially concerning since women who drink have a higher risk of alcohol-related problems. Orexin (hypocretin) receptor antagonists may have some therapeutic value for alcohol-induced insomnia; however, the use of this class of drugs following female adolescent binge drinking is limited. The current study will address whether adolescent intermittent ethanol (AIE) in female rats can result in lasting changes in sleep pathology and whether orexin-targeted treatment can alleviate these deficits.

METHODS

Following a 5-week AIE vapor model, young adult rats were evaluated on waking event-related oscillations (EROs) and EEG sleep. Subsequently, AIE rats were treated with orexin receptor 2 (OX₂ R) antagonist (MK-1064; 10, 20mg/kg) to test for modifications in sleep pathology and waking ERO.

RESULTS

Female AIE rats exhibited lasting changes in sleep compared to controls. This was demonstrated by increased fragmentation of slow wave sleep (SWS) and rapid eye movement sleep, as well as reductions in delta and theta power during SWS. There was no impact of AIE on waking EROs. Acute MK-1064 hastened SWS onset and increased the number of SWS episodes, without increasing sleep fragmentation in AIE and controls. While treatment with MK-1064 did not impact sleep EEG spectra, waking ERO energy was increased in delta, theta, and beta frequency bands.

CONCLUSIONS

These results demonstrate that AIE can produce lasting changes in sleep in female rats, highly similar to what we previously found in males. Additionally, while the OX₂ R antagonist promoted sleep in both alcohol-exposed and unexposed rats, it did not reverse most of the alcohol-induced disruptions in sleep. Thus, OX₂ R antagonism may serve as a potential therapeutic strategy for the treatment of insomnia, but not the specific signs of alcohol-induced insomnia.

Sex/gender differences in brain function and structure in alcohol use: A narrative review of neuroimaging findings over the last 10 years

Over the last 10 years, rates of alcohol use disorder (AUD) have increased in women by 84% relative to a 35% increase in men. Rates of alcohol use and high-risk drinking have also increased in women by 16% and 58% relative to a 7% and 16% increase in men, respectively, over the last decade. This robust increase in drinking among women highlights the critical need to identify the underlying neural mechanisms that may contribute to problematic alcohol consumption across sex/gender (SG), especially given that many neuroimaging studies are underpowered to detect main or interactive effects of SG on imaging outcomes. This narrative review aims to explore the recent neuroimaging literature on SG differences in brain function and structure as it pertains to alcohol across positron emission tomography, magnetic resonance imaging, and functional magnetic resonance imaging modalities in humans. Additional work using magnetic resonance spectroscopy, diffusion tensor imaging, and event-related potentials to examine SG differences in AUD will be covered. Overall, current research on the neuroimaging of AUD, alcohol consumption, or risk of AUD is limited, and findings are mixed regarding the effect of SG on neurochemical, structural, and functional mechanisms associated with AUD. We address SG disparities in the neuroimaging of AUD and propose a call to action to include women in brain imaging research. Future studies are crucial to our understanding of the neurobiological underpinnings of AUD across neural systems and the vulnerability for AUD among women and men.

Addictions NeuroImaging Assessment (ANIA): Towards an integrative framework for alcohol use disorder

Alcohol misuse and addiction are major international public health issues. Addiction can be characterized as a disorder of aberrant neurocircuitry interacting with environmental, genetic and social factors. Neuroimaging in alcohol misuse can thus provide a critical window into underlying neural mechanisms, highlighting possible treatment targets and acting as clinical biomarkers for predicting risk and treatment outcomes. This neuroimaging review on alcohol misuse in humans follows the Addictions Neuroclinical Assessment (ANA) that proposes incorporating three functional neuroscience domains integral to the neurocircuitry of addiction: incentive salience and habits, negative emotional states, and executive function within the context of the addiction cycle. Here we review and integrate multiple imaging modalities focusing on underlying cognitive processes such as reward anticipation, negative emotionality, cue reactivity, impulsivity, compulsivity and executive function. We highlight limitations in the literature and propose a model forward in the use of neuroimaging as a tool to understanding underlying mechanisms and potential clinical applicability for phenotyping of heterogeneity and predicting risk and treatment outcomes.

Convergent Evidence for Predispositional Effects of Brain Gray Matter Volume on Alcohol Consumption

BACKGROUND

Alcohol use has been reliably associated with smaller subcortical and cortical regional gray matter volumes (GMVs). Whether these associations reflect shared predisposing risk factors or causal consequences of alcohol use remains poorly understood.

METHODS

Data came from 3 neuroimaging samples (N = 2423), spanning childhood or adolescence to middle age, with prospective or family-based data. First, we identified replicable GMV correlates of alcohol use. Next, we used family-based and longitudinal data to test whether these associations may plausibly reflect a predispositional liability for alcohol use or a causal consequence of alcohol use. Finally, we used heritability, gene-set enrichment, and transcriptome-wide association study approaches to evaluate whether genome-wide association study-defined genomic risk for alcohol consumption is enriched for genes that are preferentially expressed in regions that were identified in our neuroimaging analyses.

RESULTS

Smaller right dorsolateral prefrontal cortex (DLPFC) (i.e., middle and superior frontal gyri) and insula GMVs were associated with increased alcohol use across samples. Family-based and prospective longitudinal data suggest that these associations are genetically conferred and that DLPFC GMV prospectively predicts future use and initiation. Genomic risk for alcohol use was enriched in gene sets that were preferentially expressed in the DLPFC and was associated with replicable differential gene expression in the DLPFC.

CONCLUSIONS

These data suggest that smaller DLPFC and insula GMV plausibly represent genetically conferred predispositional risk factors for, as opposed to consequences of, alcohol use. DLPFC and insula GMV represent promising biomarkers for alcohol-consumption liability and related psychiatric and behavioral phenotypes.