Alcohol-Induced Blackout: Phenomenology, Biological Basis, and Gender Differences

Oleanolic acid protects ethanol-induced memory impairments

A moderate amount of ethanol (EtOH) intake can lower the incidence of various cardiovascular disease but can result in neuropsychiatric issues during adolescence. EtOH acts on GABAA receptor, which can slow down neurotransmission and lead to changes in synaptic functions. These neurological changes due to EtOH can result in transient memory loss and may increase the risk of developing various neurological and psychiatric disorders such as dementia. Therefore, there is a need for strategies to overcome EtOH-induced brain dysfunctions. In this study, we investigated the effects of oleanolic acid (OA) on EtOH-induced memory impairment. OA blocked functional impairment of N-methyl-D-aspartate receptors (NMDAR), which are a key mechanism in EtOH-induced memory impairments. OA inhibited the removal of the major subunit of NMDAR, NR2a, from synapses induced by EtOH. Based on this, OA inhibited the impairment of object recognition memory caused by EtOH. Although OA failed to modulate the blood alcohol and acetaldehyde levels in EtOH-treated mice, OA blocked EtOH-induced increase in brain allopregnalone level with reducing 5α-reductase level. These results indicate that OA inhibits EtOH-induced memory impairment by regulating NMDAR function and passably modulates neurosteroid system.

A longitudinal study of the relationship between alcohol-related blackouts and attenuated structural brain development

PURPOSE

Alcohol-related blackouts (ARBs) are common in adolescents and emerging adults. ARBs may also be indicative of persistent, alcohol-related neurocognitive changes. This study explored ARBs as a predictor of altered structural brain development and associated cognitive correlates.

METHODS

Longitudinal growth curve modeling estimated trajectories of brain volume across 6 years in participants from the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study (n = 800, 213 with lifetime ARB history). While controlling for demographics and overall alcohol use, ARB history was analyzed as a predictor of brain volume growth in regions associated with alcohol-related cognitive change. Post hoc analyses examined whether ARBs moderated relationships between brain morphology and cognition.

RESULTS

ARBs significantly predicted attenuated development of fusiform gyrus and hippocampal volume at unique timepoints compared to overall alcohol use. Alcohol use without ARBs significantly predicted attenuated fusiform and hippocampal growth at earlier and later timepoints, respectively. Despite altered development in regions associated with memory, ARBs did not significantly moderate relationships between brain volume and cognitive performance.

CONCLUSION

ARBs and overall alcohol use predicted altered brain development in the fusiform gyrus and hippocampus at different timepoints, suggesting ARBs represent a unique marker of neurocognitive risk in younger drinkers.

Transdermal alcohol concentration features predict alcohol-induced blackouts in college students

BACKGROUND

Alcohol-induced blackouts (AIBs) are common in college students. Individuals with AIBs also experience acute and chronic alcohol-related consequences. Research suggests that how students drink is an important predictor of AIBs. We used transdermal alcohol concentration (TAC) sensors to measure biomarkers of increasing alcohol intoxication (rise rate, peak, and rise duration) in a sample of college students. We hypothesized that the TAC biomarkers would be positively associated with AIBs.

METHODS

Students were eligible to participate if they were aged 18-22 years, in their second or third year of college, reported drinking 4+ drinks on a typical Friday or Saturday, experienced ≥1 AIB in the past semester, owned an iPhone, and were willing to wear a sensor for 3 days each weekend. Students (N = 79, 55.7% female, 86.1% White, Mage = 20.1) wore TAC sensors and completed daily diaries over four consecutive weekends (89.9% completion rate). AIBs were assessed using the Alcohol-Induced Blackout Measure-2. Logistic multilevel models were conducted to test for main effects.

RESULTS

Days with faster TAC rise rates (OR = 2.69, 95% CI: 1.56, 5.90), higher peak TACs (OR = 2.93, 95% CI: 1.64, 7.11), and longer rise TAC durations (OR = 4.16, 95% CI: 2.08, 10.62) were associated with greater odds of experiencing an AIB.

CONCLUSIONS

In a sample of "risky" drinking college students, three TAC drinking features identified as being related to rising intoxication independently predicted the risk for daily AIBs. Our findings suggest that considering how an individual drinks (assessed using TAC biomarkers), rather than quantity alone, is important for assessing risk and has implications for efforts to reduce risk. Not only is speed of intoxication important for predicting AIBs, but the height of the peak intoxication and the time spent reaching the peak are important predictors, each with different implications for prevention.

The Interaction of Cannabis Consumption with Heavy Episodic Drinking and Alcohol-induced Blackouts in Relation to Cannabis Use Consequences Among Recent Undergraduate College Cannabis Users

Introduction

Risky alcohol use patterns, characterized by heavy episodic drinking (HED) and alcohol-induced blackout, are prevalent in college students. However, it is not clear if experiencing HED and blackout among college-attending cannabis users heightens risk for adverse cannabis use consequences. The purpose of this study was to examine whether heavy episodic drinking and blackout episodes moderate the relationship between cannabis consumption and cannabis use consequences among college students.

Methods

Undergraduate college students (n = 4331) were recruited from a Midwest University in 2021. This analysis used a subset of data from past 6-month cannabis users (n= 772; 17.8% of the full sample). Among cannabis users, 64.5% identified as female and 87.8% were White with an average age of 19.99 (SD=2.88). A linear regression was conducted with two two-way interactions of cannabis consumption and HED frequency as well as cannabis consumption and alcohol-induced blackout episodes.

Results

Results showed a statistically significant positive association between cannabis consumption and cannabis use consequences (B=0.73, p<.001), adjusting for the other variables in the model. Blackout, but not HED, was a significant moderator (B=0.19, p=.003).

Discussion

The findings of this study indicate that blackout experiences amplify the relationship between cannabis use and cannabis-related consequences among college students. This underscores that blackouts not only signal a risk of problematic drinking but also exacerbate the association between cannabis use and its negative consequences.

Conclusion

Findings may inform college campus interventions targeting cannabis and alcohol concurrent-users who experience alcohol-induced blackouts to reduce their additional risk for cannabis-related consequences.

Cross state-dependent memory retrieval between tramadol and ethanol: involvement of dorsal hippocampal GABAA receptors

RATIONALE

Tramadol and ethanol, as psychoactive agents, are often abused. Discovering the molecular pathways of drug-induced memory creation may contribute to preventing drug addiction and relapse.

OBJECTIVE

The tramadol- and ethanol-induced state-dependent memory (SDM) and cross-SDM retrieval between tramadol and ethanol were examined in this study. Moreover, because of the confirmed involvement of GABAA receptors and GABAergic neurotransmission in memory retrieval impairment, we assessed cross-SDM retrieval between tramadol and ethanol with a specific emphasis on the role of the GABAA receptors. The first hypothesis of this study was the presence of cross-SDM between tramadol and ethanol, and the second hypothesis was related to possible role of GABAA receptors in memory retrieval impairment within the dorsal hippocampus. The cannulae were inserted into the hippocampal CA1 area of NMRI mice, and a step-down inhibitory avoidance test was used to evaluate state dependence and memory recovery.

RESULTS

The post-training and/or pre-test administration of tramadol (2.5 and 5 mg/kg, i.p.) and/or ethanol (0.5 and 1 g/kg, i.p.) induced amnesia, which was restored after the administration of the drugs 24 h later during the pre-test period, proposing ethanol and tramadol SDM. The pre-test injection of ethanol (0.25 and 0.5 g/kg, i.p.) with tramadol at an ineffective dose (1.25 mg/kg) enhanced tramadol SDM. Moreover, tramadol injection (1.25 and 2.5 mg/kg) with ethanol at the ineffective dose (0.25 g/kg) promoted ethanol SDM. Furthermore, the pre-test intra-CA1 injection of bicuculline (0.0625, 0.125, and 0.25 μg/mouse), a GABAA receptor antagonist, 5 min before the injection of tramadol (5 mg/kg) or ethanol (1 g/kg) inhibited tramadol- and ethanol-induced SDM dose-dependently.

CONCLUSION

The findings strongly confirmed cross-SDM between tramadol and ethanol and the critical role of dorsal hippocampal GABAA receptors in the cross-SDM between tramadol and ethanol.

Wearable alcohol monitors for alcohol use data collection among college students: Feasibility and acceptability

OBJECTIVE

We assessed the feasibility and acceptability of using BACtrack Skyn wearable alcohol monitors for alcohol research in a college student population.

METHODS

We enrolled n = 5 (Sample 1) and n = 84 (Sample 2) Indiana University undergraduate students to wear BACtrack Skyn devices continuously over a 5-day to 7-day study period. We assessed feasibility in both samples by calculating compliance with study procedures, and by analyzing amount and distributions of device output [e.g., transdermal alcohol content (TAC), temperature, motion]. In Sample 1, we assessed feasibility and acceptability with the Feasibility of Intervention Measure (FIM) scale and the Acceptability of Intervention Measure (AIM) scale.

RESULTS

All participants were able to successfully use the alcohol monitors, producing a total of 11,504 h of TAC data. TAC data were produced on 567 days of the 602 total possible days of data collection. The distribution of the TAC data showed between-person variation, as would be expected with between-person differences in drinking patterns. Temperature and motion data were also produced as expected. Sample 1 participants (n = 5) reported high feasibility and acceptability of the wearable alcohol monitors in survey responses with a mean FIM score of 4.3 (of 5.0 possible score) and mean AIM score of 4.3 (of 5.0 possible score).

CONCLUSIONS

The high feasibility and acceptability we observed underscore the promise of using BACtrack Skyn wearable alcohol monitors to improve our understanding of alcohol consumption among college students, a population at particularly high risk for alcohol-related harms.

Does it really matter that I do not remember my night? Consequences related to blacking out among college student drinkers

BACKGROUND

Alcohol-induced blackouts (AIBs) are experienced frequently by college student drinkers and are more likely to occur on days with high-intensity drinking (HID; 8+ for females/10+ for males) than non-HID days. Research suggests that AIBs are associated with experiencing other alcohol-related consequences (ARCs), including more serious ARCs (SARCs; e.g., legal and sexual consequences), but we do not know whether individuals experience more ARCs and more SARCs on occasions when they black out than when they do not black out. This study examines the associations between AIBs and the total number of both ARCs and SARCs.

METHODS

Students (N = 462, 51.7% female, 87.7% White, Mage  = 20.1) were assessed across 6 weekends via e-surveys (80%-97% response rate). Multilevel models were used to test for main effects, controlling for drinking (HID or estimated blood alcohol concentration; eBAC) and sex.

RESULTS

Drinking days when an AIB was experienced were associated with more total ARCs (b = 3.54, 95% CI: 3.10, 3.99) and more SARCs (b = 0.77, 95% CI: 0.60, 0.95) per day than non-AIB days. The more frequently a person experienced an AIB, the more total ARCs (b = 5.33, 95% CI: 4.40, 6.25) and SARCs (1.05, 95% CI: 0.80, 1.30) they reported on average.

CONCLUSION

Alcohol-induced blackout days were associated with higher levels of harm than non-AIB days, even at the same levels of drinking. Interventions that focus on reducing the occurrence of AIBs and factors that contribute to them, in addition to reducing alcohol consumption, may help reduce total harm associated with drinking among college students.

Experience with dronabinol consumption facilitated a stimulant effect of alcohol and affected alcohol-related changes in frontal cortical endocannabinoid levels in male rats

Combined use of cannabis and alcohol is common in adolescents. However, the extent to which such polydrug exposure affects the brain and behaviors remains under-investigated in preclinical studies. This study tested the hypothesis that combined exposure of Δ-9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, and alcohol will have additive effects on cognitive impairments and altered endocannabinoid levels in the hippocampus and frontal cortex. Male Long Evans rats were provided with daily access to cookies laced with oil or dronabinol, a synthetic THC, during adolescence. Three days after discontinuation of edible THC, the effect of orally administered 3 g/kg alcohol on Barnes maze performance was assessed. The results showed that experience with edible THC facilitated the occurrence of increased moving speed on the maze induced by repeated alcohol administration. However, contrasting to the hypothesis, the combined THC and alcohol exposure did not lead to additive deficits in learning and memory on the Barnes maze. While little effect on endocannabinoid levels was observed in the hippocampus, acute abstinence from alcohol significantly reduced endocannabinoid levels in the frontal cortex. In particular, reduction of N-oleoyl ethanolamine (OEA) and N-stearoyl ethanolamine (SEA) were robust and had an interactive effect with discontinuation from edible THC. These findings add to the scarce literature on THC and alcohol associated changes in endocannabinoid levels and provide insights to future investigations on the roles of OEA and SEA on physiology and behaviors following THC and alcohol co-exposure during adolescence.

Alcohol-induced blackouts among college student drinkers: A multilevel analysis

OBJECTIVE

To identify factors (manner of drinking, combined alcohol and other substance use, physiology) that are associated with alcohol-induced blackouts (AIBs) over and above estimated blood alcohol concentration (eBAC).

METHODS

Students (N = 462, 51.7 % female, 87.7 % White, Mage = 20.1) were assessed across 6 weekends via e-surveys (80-97 % response rate). eBAC was calculated using standard number of drinks, drinking duration, sex, and weight. Three-level multilevel models (days, weeks, persons) were conducted to test for main effects, controlling for eBAC.

RESULTS

Protective behavioral strategies (PBS) were associated with decreased odds of AIBs on the daily (OR = 0.64, 95 % CI: 0.53, 0.77), weekly (OR = 0.84, 95 % CI: 0.72, 0.98), and person-levels (OR = 0.62, 95 % CI: 0.51, 0.74). Combined cannabis with alcohol was associated with increased odds of AIBs on the weekly (OR = 2.13, 95 % CI 1.13, 4.07) and person-levels (OR = 3.56, 95 % CI 1.60, 7.93). People who more frequently played drinking games (OR = 1.41, 95 % CI: 1.12, 1.77), pregamed (OR = 1.55, 95 % CI: 1.19, 2.03), and showed higher tolerance (OR = 1.22, 95 % CI: 1.08, 1.37) showed increased risk of AIBs, over and above eBAC levels.

CONCLUSION

We identified a number of daily-, weekly-, and person-level factors that uniquely contribute to the prediction of AIBs even at equivalent eBACs. Many of these factors were behavioral, suggesting that they may serve as malleable prevention targets for AIBs in college student drinkers.

Alcohol and the central nervous system

Ethanol use is common to most cultures but with varying doses and to varying extents. While research has focused on the effects on the liver, alcohol exerts a range of actions on the function and structure of the nervous system. In the central nervous system (CNS) it can provoke or exacerbate neurological and psychiatric disease; its effects on the peripheral nervous system are not included in this review. Sustained alcohol intake can predispose to acute neurochemical changes which, with continued ingestion and incomplete treatment, can lead to chronic structural changes in the CNS: these include generalised cortical and cerebellar atrophy, amnesic syndromes such as Korsakoff's syndrome, and specific white matter disorders such as central pontine myelinolysis and Marchiafava-Bignami syndrome. Alcohol in pregnancy commonly and significantly affects fetal health, though this receives less medical and political attention than other causes of fetal harm. This review looks at the range of disorders that can follow acute or chronic alcohol use, and how these should be managed, and we provide a practical overview on how neurologists might diagnose and manage alcohol addiction.

Targeting Persistent Changes in Neuroimmune and Epigenetic Signaling in Adolescent Drinking to Treat Alcohol Use Disorder in Adulthood

Studies universally find early age of drinking onset is linked to lifelong risks of alcohol problems and alcohol use disorder (AUD). Assessment of the lasting effect of drinking during adolescent development in humans is confounded by the diversity of environmental and genetic factors that affect adolescent development, including emerging personality disorders and progressive increases in drinking trajectories into adulthood. Preclinical studies using an adolescent intermittent ethanol (AIE) exposure rat model of underage binge drinking avoid the human confounds and support lifelong changes that increase risks. AIE increases adult alcohol drinking, risky decision-making, reward-seeking, and anxiety as well as reductions in executive function that all increase risks for the development of an AUD. AIE causes persistent increases in brain neuroimmune signaling high-mobility group box 1 (HMGB1), Toll-like receptor, receptor for advanced glycation end products, and innate immune genes that are also found to be increased in human AUD brain. HMGB1 is released from cells by ethanol, both free and within extracellular vesicles, that act on neurons and glia, shifting transcription and cellular phenotype. AIE-induced decreases in adult hippocampal neurogenesis and loss of basal forebrain cholinergic neurons are reviewed as examples of persistent AIE-induced pathology. Both are prevented and reversed by anti-inflammatory and epigenetic drugs. Findings suggest AIE-increased HMGB1 signaling induces the RE-1 silencing transcript blunting cholinergic gene expression, shifting neuronal phenotype. Inhibition of HMGB1 neuroimmune signaling, histone methylation enzymes, and galantamine, the cholinesterase inhibitor, both prevent and reverse AIE pathology. These findings provide new targets that may reverse AUD neuropathology as well as other brain diseases linked to neuroimmune signaling. SIGNIFICANCE STATEMENT: Adolescent underage binge drinking studies find that earlier adolescent drinking is associated with lifelong alcohol problems including high levels of lifetime alcohol use disorder (AUD). Preclinical studies find the underage binge drinking adolescent intermittent ethanol (AIE) model causes lasting changes in adults that increase risks of developing adult alcohol problems. Loss of hippocampal neurogenesis and loss of basal forebrain cholinergic neurons provide examples of how AIE-induced epigenetic and neuroimmune signaling provide novel therapeutic targets for adult AUD.

Recent alcohol-induced blackouts among heavy drinking college students: A qualitative examination of intentions, willingness, and social context

One-third to half of emerging adult drinkers report experiencing alcohol-induced blackouts in the past year, and blackouts increase the risk for negative consequences. Qualitative methods provide valuable tools for scientific inquiry, allowing for in-depth understanding of lived experiences. The goal of the present study was to gain insight into emerging adults' recent blackout experiences. One hundred heavy drinking college students (age 18-20) completed a baseline survey, 28 days of ecological momentary assessment (EMA) of their alcohol use and consequences, and a follow-up interview. A subset of 37 (46% female, 13.5% Hispanic/Latinx, 54% non-Hispanic ethnicity/White race) endorsed a blackout (forgot what they did during or after drinking) and were interviewed regarding their recent blackout experience. A semi-structured interview guide focused on several key questions regarding intentions and/or willingness to black out, how friends reacted to their blackout, and social norms for blacking out. A priori as well as emergent themes were generated from review of coded data. Qualitative themes included: blackouts are often unintentional, heavy drinking young adults express willingness to black out, friends react in a variety of ways to blackouts, and blackouts are perceived as common and acceptable. Data provide insight into the phenomenology of blackouts among college students, revealing that although college students may not intend to, they are often willing to black out. Future qualitative studies on blackouts among non-college-attending emerging adults are warranted. Such work can inform theory and future survey studies to better understand this high-risk behavior. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A mixed-methods approach to improve the measurement of alcohol-induced blackouts: ABOM-2

BACKGROUND

Alcohol-induced blackouts describe memory loss resulting from alcohol consumption. Approximately half of college students report experiencing a blackout in their lifetime. Blackouts are associated with an increased risk for negative consequences, including serious injury. Research has documented two types of blackouts, en bloc (EB) and fragmentary (FB). However, research is limited by the lack of a validated measure that differentiates between these two forms of blackout. This study used a mixed-methods approach to improve the assessment of FB and EB among young adults. Specifically, we sought to improve the existing Alcohol-Induced Blackout Measure (ABOM), which was derived from a relatively small pool of items that did not distinguish FB from EB.

METHODS

Study 1 used three rounds of cognitive interviewing with U.S. college students (N = 31) to refine existing assessment items. Nineteen refined blackout items were retained for Study 2. Study 2 used face validity, factor analysis, item response theory, and external validation analyses to test the two-factor blackout model among U.S. heavy-drinking college students (N = 474) and to develop and validate a new blackout measure (ABOM-2).

RESULTS

Iterative factor analyses demonstrated that the items were well represented by correlated EB and FB factors, consistent with our hypothesis. External validation analyses demonstrated convergent and discriminant validity. These analyses also provided preliminary evidence for the two factors having differential predictive validity (e.g., FB correlated with enhancement drinking motives, while EB correlated with coping and conformity motives).

CONCLUSIONS

The Alcohol-Induced Blackout Measure-2 (ABOM-2) improves the measurement of blackout experiences among college students. Its use could facilitate the examination of EB and FB as differential predictors of alcohol-related outcomes in future studies.

Victim Behavior in a Sample of Military Sexual Assault Cases

This study explored victim responses to sexual assault within a military context. Victim behavior was identified in forensic case files of service members charged with sexual assault (N = 58) and referred for forensic evaluation or consultation. The identified victim behavior was coded and quantified for description. Of the sample 87.9% of victims were female and 12.0% of victims were male; 37.9% of the victims reported their assault in less than 1 month. Forceful resistance to the assault occurred in 15.5% of the cases. Physical injury associated with the sexual assault was absent in 96.5% of the cases. The description of victim behavior can inform forensic expert testimony on victim behavior within the military justice system while also offering empirical evidence to better understand this public health problem in the U.S. military.

A Longitudinal Examination of Alcohol-Related Blackouts as a Predictor of Changes in Learning, Memory, and Executive Function in Adolescents

INTRODUCTION

In adolescents, the relationship between alcohol-related blackouts (ARBs) and distinct cognitive changes lasting beyond intoxication is unclear. We examined ARBs as a predictor of persistent changes in the development of learning, memory, and executive function in participants from the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study.

METHODS

Descriptive analyses of the NCANDA sample (N = 831, 50.9% female, 12-21 years at baseline) identified ARB patterns within participants with an ARB history (n = 106). Latent growth curve modeling evaluated ARB-related performance changes on four neuropsychological measures across five years, excluding baseline data to reduce the magnitude of practice effects over time (n = 790). Measures included the Penn Conditional Exclusion Test (PCET), Penn Letter N-back Test (PLBT), Penn Facial Memory Test immediate (PFMT_i), and delayed (PFMT_d) recognition trials, and the Rey Complex Figure Test copy (RCFT_c), immediate recall (RCFT_i), and delayed recall (RCFT_d) trials. Multivariate models were fit for raw accuracy scores from each measure, with ARB history (i.e., presence of past-year ARBs) as the main independent variable. Age, sex, race, socioeconomic status, assessment site, and alcohol use (i.e., past-year frequency) were included as covariates. Interaction effects between ARB history and alcohol use frequency were tested.

RESULTS

By year five, 16% of participants had experienced at least one ARB (59% of whom reported > 1 ARB and 57% of whom had an ARB lasting > 1 h). After controlling for demographics and alcohol use, ARB history predicted attenuated PFMT_d performance growth at year one. Interaction effects between ARB history and alcohol use frequency predicted attenuated PFMT_d performance growth at years one and two. ARB history predicted attenuated RCFT_i and RCFT_d performance growth by year four, but not PCET or PLBT performance over time. By contrast, greater past-year alcohol use predicted attenuated PFMT_i and PFMT_d performance growth between years two and four in adolescents without an ARB history.

CONCLUSION

We found that ARBs predict distinct, lasting changes in learning and memory for visual information, with results suggesting that the developing brain is vulnerable to ARBs during adolescence and emerging adulthood.

Opportunities for reducing college drinking: The roles of drinking attitudes and blackout experience

BACKGROUND

As many as 35% of college students report having been drunk in the past month, and greater alcohol use and alcohol-related problems are associated with a positive attitude toward heavy drinking. One serious consequence of heavy drinking is alcohol-induced blackout. When they occur, alcohol-induced blackouts present a unique opportunity to increase motivation to change drinking. However, it is unclear under what conditions an alcohol-related heavy drinking attitude and experiencing a blackout represent an opportunity to change and how experiencing a blackout(s) influences an individual's motivation to reduce drinking and actual behavior.

METHODS

This study tested the interplay between one's positive attitude toward heavy drinking and experiencing a blackout in the past year in predicting motivation to reduce drinking (Study 1) and its impact on drinking over time (Study 2). Data were derived from complementary datasets collected at two universities (Study 1 n = 703, mean age = 20.63 years, 44% male, 52% White; Study 2 n = 568, mean age = 19.18 years, 72% male, 84% White). Drinking behavior was measured using a modified Daily Drinking Questionnaire, the Drinking Norms Rating Form, the Alcohol Use Disorders Identification Test (AUDIT), and estimated peak blood alcohol concentration (BAC). Regression analyses were conducted to determine whether a blackout would moderate the association between attitude and motivation to reduce drinking (Study 1) and drinking over time (Study 2).

RESULTS

Results revealed a significant interaction between attitude and blackout, such that individuals who experience a blackout (vs. those who do not) and positively evaluate heavy drinking evidenced lower motivation to reduce drinking (Study 1) and higher levels of estimated peak BAC (Study 2).

CONCLUSIONS

Drinkers with a negative attitude toward heavy drinking who have experienced a blackout have the strongest motivation to reduce drinking and the greatest reductions in peak drinking behavior over time. These effects are over and above that related to the level of alcohol consumed. For young adults who do not positively endorse heavy drinking, blackouts may present a "moment of opportunity" for intervention.

Effects of moderate alcohol levels on default mode network connectivity in heavy drinkers

BACKGROUND

It is well established that even moderate levels of alcohol affect cognitive functions such as memory, self-related information processing, and response inhibition. Nevertheless, the neural mechanisms underlying these alcohol-induced changes are still unclear, especially on the network level. The default mode network (DMN) plays an important role in memory and self-initiated mental activities; hence, studying functional interactions of the DMN may provide new insights into the neural mechanisms underlying alcohol-related changes.

METHODS

We investigated resting-state functional connectivity (rsFC) of the DMN in a cohort of 37 heavy drinkers at a breath alcohol concentration of 0.8 g/kg. Alcohol and saline were infused in a single-blind crossover design.

RESULTS

Intranetwork connectivity analyses revealed that participants showed significantly decreased rsFC of the right hippocampus and right middle temporal gyrus during acute alcohol exposure. Moreover, follow-up analyses revealed that these rsFC decreases were more pronounced in participants who reported stronger craving for alcohol. Exploratory internetwork connectivity analyses of the DMN with other resting-state networks showed no significant alcohol-induced changes, but suffered from low statistical power.

CONCLUSIONS

Our results indicate that acute alcohol exposure affects rsFC within the DMN. Functionally, this finding may be associated with impairments in memory encoding and self-referential processes commonly observed during alcohol intoxication. Future resting-state functional magnetic resonance imaging studies might therefore also investigate memory function and test whether DMN-related connectivity changes are associated with alcohol-induced impairments or craving.

Alcohol use disorders and the brain

A diagnosis of alcohol use disorder is associated with a higher risk of dementia, but a dose-response relationship between alcohol intake consumption and cognitive impairment remains unclear. Alcohol is associated with a range of effects on the central nervous system at different doses and acts on a number of receptors. Acute disorders include Wernicke's encephalopathy (WE), traumatic brain injury, blackouts, seizures, stroke and hepatic encephalopathy. The most common manifestations of chronic alcohol consumption are Korsakoff's syndrome (KS) and alcohol-related dementia (ARD). There is limited evidence for benefit from memantine in the treatment of ARD, but stronger evidence for the use of high-dose parenteral thiamine in the progression of neuropsychiatric symptoms for WE. Accumulating evidence exists for pharmacological treatment in the prevention of hepatic encephalopathy. Rehabilitation of people with ARD may take several years, and requires an approach that addresses physical and psychosocial factors.

Activation of Melanocortin-4 Receptor by a Synthetic Agonist Inhibits Ethanolinduced Neuroinflammation in Rats

BACKGROUND

High ethanol intake induces a neuroinflammatory response resulting in the subsequent maintenance of chronic alcohol consumption. The melanocortin system plays a pivotal role in the modulation of alcohol consumption. Interestingly, it has been shown that the activation of melanocortin-4 receptor (MC4R) in the brain decreases the neuroinflammatory response in models of brain damage other than alcohol consumption, such as LPS-induced neuroinflammation, cerebral ischemia, glutamate excitotoxicity, and spinal cord injury.

OBJECTIVES

In this work, we aimed to study whether MC4R activation by a synthetic MC4R-agonist peptide prevents ethanol-induced neuroinflammation, and if alcohol consumption produces changes in MC4R expression in the hippocampus and hypothalamus.

METHODS

Ethanol-preferring Sprague Dawley rats were selected offering access to 20% ethanol on alternate days for 4 weeks (intermittent access protocol). After this time, animals were i.p. administered an MC4R agonist peptide in the last 2 days of the protocol. Then, the expression of the proinflammatory cytokines interleukin 6 (IL-6), interleukin 1-beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) were measured in the hippocampus, hypothalamus and prefrontal cortex. It was also evaluated if ethanol intake produces alterations in the expression of MC4R in the hippocampus and the hypothalamus.

RESULTS

Alcohol consumption increased the expression of MC4R in the hippocampus and the hypothalamus. The administration of the MC4R agonist reduced IL-6, IL-1β and TNF-α levels in hippocampus, hypothalamus and prefrontal cortex, to those observed in control rats that did not drink alcohol.

CONCLUSION

High ethanol consumption produces an increase in the expression of MC4R in the hippocampus and hypothalamus. The administration of a synthetic MC4R-agonist peptide prevents neuroinflammation induced by alcohol consumption in the hippocampus, hypothalamus, and prefrontal cortex. These results could explain the effect of α-MSH and other synthetic MC4R agonists in decreasing alcohol intake through the reduction of the ethanol-induced inflammatory response in the brain.

Random Forest Classification of Alcohol Use Disorder Using EEG Source Functional Connectivity, Neuropsychological Functioning, and Impulsivity Measures

: Individuals with alcohol use disorder (AUD) manifest a variety of impairments that can be attributed to alterations in specific brain networks. The current study aims to identify features of EEG-based functional connectivity, neuropsychological performance, and impulsivity that can classify individuals with AUD (N = 30) from unaffected controls (CTL, N = 30) using random forest classification. The features included were: (i) EEG source functional connectivity (FC) of the default mode network (DMN) derived using eLORETA algorithm, (ii) neuropsychological scores from the Tower of London test (TOLT) and the visual span test (VST), and (iii) impulsivity factors from the Barratt impulsiveness scale (BIS). The random forest model achieved a classification accuracy of 80% and identified 29 FC connections (among 66 connections per frequency band), 3 neuropsychological variables from VST (total number of correctly performed trials in forward and backward sequences and average time for correct trials in forward sequence) and all four impulsivity scores (motor, non-planning, attentional, and total) as significantly contributing to classifying individuals as either AUD or CTL. Although there was a significant age difference between the groups, most of the top variables that contributed to the classification were not significantly correlated with age. The AUD group showed a predominant pattern of hyperconnectivity among 25 of 29 significant connections, indicating aberrant network functioning during resting state suggestive of neural hyperexcitability and impulsivity. Further, parahippocampal hyperconnectivity with other DMN regions was identified as a major hub region dysregulated in AUD (13 connections overall), possibly due to neural damage from chronic drinking, which may give rise to cognitive impairments, including memory deficits and blackouts. Furthermore, hypoconnectivity observed in four connections (prefrontal nodes connecting posterior right-hemispheric regions) may indicate a weaker or fractured prefrontal connectivity with other regions, which may be related to impaired higher cognitive functions. The AUD group also showed poorer memory performance on the VST task and increased impulsivity in all factors compared to controls. Features from all three domains had significant associations with one another. These results indicate that dysregulated neural connectivity across the DMN regions, especially relating to hyperconnected parahippocampal hub as well as hypoconnected prefrontal hub, may potentially represent neurophysiological biomarkers of AUD, while poor visual memory performance and heightened impulsivity may serve as cognitive-behavioral indices of AUD.

Activation of Melanocortin-4 Receptor Inhibits Both Neuroinflammation Induced by Early Exposure to Ethanol and Subsequent Voluntary Alcohol Intake in Adulthood in Animal Models: Is BDNF the Key Mediator?

The concept that neuroinflammation induced by excessive alcohol intake in adolescence triggers brain mechanisms that perpetuate consumption has strengthened in recent years. The melanocortin system, composed of the melanocortin 4 receptor (MC4R) and its ligand α-melanocyte-stimulating hormone (α-MSH), has been implicated both in modulation of alcohol consumption and in ethanol-induced neuroinflammation decrease. Chronic alcohol consumption in adolescent rats causes a decrease in an α-MSH release by the hypothalamus, while the administration of synthetic agonists of MC4R causes a decrease in neuroinflammation and a decrease in voluntary alcohol consumption. However, the mechanism that connects the activation of MC4R with the decrease of both neuroinflammation and voluntary alcohol consumption has not been elucidated. Brain-derived neurotrophic factor (BDNF) has been implicated in alcohol drinking motivation, dependence and withdrawal, and its levels are reduced in alcoholics. Deficiencies in BDNF levels increased ethanol self-administration in rats. Further, BDNF triggers important anti-inflammatory effects in the brain, and this could be one of the mechanisms by which BDNF reduces chronic alcohol intake. Interestingly, MC4R signaling induces BDNF expression through the activation of the cAMP-responsive element-binding protein (CREB). We hypothesize that ethanol exposure during adolescence decreases the expression of α-MSH and hence MC4R signaling in the hippocampus, leading to a lower BDNF activity that causes dramatic changes in the brain (e.g., neuroinflammation and decreased neurogenesis) that predispose to maintain alcohol abuse until adulthood. The activation of MC4R either by α-MSH or by synthetic agonist peptides can induce the expression of BDNF, which would trigger several processes that lead to lower alcohol consumption.

Difference in Cognitive Function by First Onset Age of Alcohol Induced Blackout and Its Duration

Objective

Alcohol-induced blackout (blackout) is a typical early symptom of cognitive impairment caused by drinking. However, the first onset age of blackout or the duration after onset of blackout has not been directly compared in previous studies. The purpose of this study was to investigate the differences in cognitive function to the first start age of blackouts and their duration.

Methods

Thirty-one male subjects were included in this study. Their age at the first blackout and the duration after the onset of blackout were investigated. Neuropsychological tests were conducted to determine their attention, memory, and executive function. Subjects were divided into three groups according to their age of the first onset blackout (group O1, < 20 years; group O2, 21–39 years; and group O3, > 40 years). Subjects were also divided into three groups by duration after the onset of blackout (P1, < 10 years; P2, 10–29 years; and P3, > 30 years). We then examined differences in neurocognitive function among these groups.

Results

O1 tended to have a lower memory score than O2 (F = 3.28, p = 0.053). Significant differences were observed in attention and executive function between groups P1 and P3 (Digit Span_backward: F = 6.07, p < 0.05; visual span_forward: F = 4.19, p < 0.05; executive intelligence quotient: F = 3.55, p < 0.05).

Conclusion

Greater memory impairment was detected in subjects having an earlier age of the first blackout. The longer the duration after the onset of blackout, the more impaired their attention and executive function skills.

Drink driving engagement in women: An exploration of context, hazardous alcohol use, and behaviour

Background

While drink driving continues to be significantly more common among male drivers, there is evidence from many countries that shows a growing trend of women engaging in this risky behaviour. The aims of the current study were threefold: (i) determine to what extent a sample of women drivers reported engaging in drink driving behaviour by expanding the construct into a range of definitions, (ii) determine if there were significant differences in self-reported engagement in drink driving behaviours in accordance with hazardous drinking behaviour, and (iii) identify which situational or personal factors would increase women drivers’ likelihood to engage in drink driving through presenting a range of scenarios.

Method

Data were collected using an on-line, purpose-designed survey and promoted to reach women aged 17 years and older, living in Queensland, Australia. In addition to questions relating to demographic characteristics, participants completed items relating to engagement in seven drink driving related behaviours in the previous 12-month period, hazardous drinking as measured by the Alcohol Use Disorders Identification Test, and likelihood of driving when unsure if over the legal limit for licence type across a range of scenarios manipulating different situational factors. A total of 644 valid responses were received in the two-week period the study was advertised.

Results

The results demonstrate women’s self-reported engagement in drink driving behaviour ranged from 12.6% (driving when they believed they were over the legal limit) to over 50.0% (driving when unsure if over the legal limit the morning after drinking alcohol) and was significantly more likely among those who reported hazardous levels of alcohol use. Circumstances in which women reported they would drive when unsure if over the legal BAC limit were when they were a few blocks from home, if they subjectively felt they were not too intoxicated, or if they needed their car to get somewhere the next morning.

Conclusion

Examining drink driving behaviour by way of responses to nuanced definitions provided valuable insight into self-reported engagement in the behaviour and highlights the usefulness of multi-measure dependent variables in order to illuminate a more accurate acknowledgement into both the type (and extent) of drink driving behaviours.

Alcohol-induced blackouts at age 20 predict the incidence, maintenance and severity of alcohol dependence at age 25: a prospective study in a sample of young Swiss men

BACKGROUND AND AIMS

Alcohol-induced blackout (AIB) is a common alcohol-related adverse event occurring during teenage years. Although research provides evidence that AIB predicts acute negative consequences, less is known about the associations of AIB with chronic consequences, such as alcohol dependence (AD). This study estimated the associations between an experience of AIB at age 20 and the incidence, maintenance and severity of AD at age 25 among Swiss men.

DESIGN

Prospective cohort study with 5.5 years separating baseline and follow-up.

SETTING

Switzerland.

PARTICIPANTS

Swiss male drinkers (n = 5469, age 20 at baseline) drawn from the Cohort Study on Substance Use Risk Factors (C-SURF).

MEASUREMENTS

Self-report questionnaires assessing AIB, AD, alcohol (drinking volume, binge drinking), cigarette and cannabis use, several risk factors (sensation-seeking, family history of problematic alcohol use, age of first alcohol intoxication) and socio-demographic variables.

FINDINGS

Generalized estimating equation models with and without adjustment for risk factors, including alcohol use and socio-demographics, showed that AIB at age 20 significantly predicted the incidence of AD at age 25 in men without AD at age 20 [odds ratio (OR) = 2.52, 95% confidence interval (CI), unadjusted = 2.04, 3.11, P < 0.001; fully adjusted, OR = 1.47, 95% CI = 1.13, 1.91, P = 0.004], maintenance of AD in men with AD at age 20 (unadjusted, OR = 1.82, 95% CI = 1.12, 2.95, P = 0.015; fully adjusted, OR = 1.66, 95% CI = 1.00, 2.76, P = 0.048] and AD severity [unadjusted incidence rate ratio (IRR) = 1.89, 95% CI = 1.69, 2.11, P < 0.001; fully adjusted, IRR = 1.20, 95% CI = 1.10, 1.31, P < 0.001].

CONCLUSIONS

Among Swiss men, alcohol-induced blackout at age 20 predicts the development, maintenance and severity of alcohol dependence at age 25.

Replication of factors related to blackout incidence in U.S. high school students: A brief report

Alcohol-related blackouts are a common, yet serious consequence that can result from heavy alcohol intake. This study tested a model examining whether factors identified in related samples (i.e., adolescents residing in the U.K. and U.S. college students) predicted blackouts in community-dwelling U.S. high school youth. Participants from a Northeastern U.S. high school with prior alcohol use (M_age = 16.0 years; 48.2% male, 78.0% White) completed a paper-and-pencil assessment including measures of demographics, alcohol and other substance use, externalizing behaviors, and injunctive norms about risky drinking behaviors. Hierarchical logistic regression examined which factors identified for U.K. residing adolescents (Block 1) replicated in the U.S. sample, and whether factors identified in samples of U.S. college students added additional explained variance (Block 2). Blackouts were reported by 35.6% of students. Regression results indicated that two variables previously identified in adolescents, female gender (OR = 3.26) and increased alcohol use (OR = 1.27) were associated with blackouts. College student risk factors of drinking game (DG) participation and, to a lesser degree injunctive norms for passing out, emerged as additional risk factors (ORs = 2.85 and 1.32, respectively), with the final model explaining 39% of the variance in blackouts. This study advances our understanding of blackouts in younger drinkers and identifies the importance of addressing blackouts within the context of intervention programming that addresses cognitions and high risk drinking practices like DGs.

Genetic Epidemiology of Liability for Alcohol-Induced Blacking and Passing Out

BACKGROUND

Individuals differ in their sensitivity to alcohol's physiological effects, including blacking and passing out. Blackouts are periods of impaired memory formation when an individual engages in activities they later cannot recall, while passing out results in loss of consciousness.

METHODS

The sample consisted of 3,292 adult twins from the Australian Twin Registry. Univariate twin analyses were conducted to examine the contributions of genetic and environmental influences to blacking and passing out occurrence and susceptibility (accounting for frequency of intoxication). Evidence for shared etiology of susceptibility to blacking and passing out was examined using bivariate twin analyses.

RESULTS

Although blacking and passing out were strongly associated (odds ratio (OR) = 4.45, 95% confidence interval (CI): [3.85, 5.14]), the genetic epidemiology was quite different. Genetic (43%) and nonshared environmental (57%) influences contributed to liability for blackout occurrence. For passing out occurrence, there was evidence of sex differences. Among men, genetic (32%) and nonshared environmental (68%) influences contributed, whereas among women, there were shared (29%) and nonshared environmental (72%) influences. After accounting for frequency of intoxication, genetic influences on blackout susceptibility remained significant; in contrast, only nonshared environmental influences were significant for passing out susceptibility. There was evidence for overlapping genetic and nonshared environmental factors influencing susceptibility to blacking and passing out among men; among women, there were overlapping nonshared environmental influences.

CONCLUSIONS

Blacking and passing out are 2 common sedative-like effects of heavy drinking, and people differ considerably in their susceptibility to these effects. This study suggests that differences in blackout susceptibility can be explained by genetic factors in both men and women, while differences in susceptibility to pass out after consuming alcohol may be attributable to environmental influences, particularly among women. These environmental factors may include changing social and cultural norms about alcohol use, drinking context, and the type(s) of alcohol consumed.

Substance use and Psychosocial Functioning of Adolescents in Benue State, Nigeria: Assessing the role of age

AIM

To assess whether Substance Use (SU) is associated with Psychosocial Function (PF) among adolescent.

METHODS

Using a self-administered validated instrument, we obtained information on demographic, SU (defined as self-reported affirmative use of one or more of any form of alcoholic drinks, cigarettes, hemps etc) and PF [using the adolescent psychosocial functioning inventory comprising of three subscales; optimism and coping strategies (OCS), behaviour and relationship problems (BRP) and general psychosocial dysfunction designed (GPD)] among 2272 apparently healthy adolescents. PF was categorized as 'elevated' if the psychosocial functioning index (PFI) score were >75th percentile, otherwise, 'not elevated' and multivariable-adjusted logistic regression was used to compute odds ratio (OR) and 95% confidence interval (CI) of SU for elevated PF risk. In addition, we applied Johnson Neyman (JN) technique to identifying the JN significance regions at which age moderated the SU-PF relationship at a statistical significance of two-sided P<0.05.

RESULTS

Prevalence of SU and elevated PF was 50.7% and 79.8% respectively. Prevalence of elevated PF differed insignificantly by sex, but the proportion of adolescent with elevated PFI on SU (82.6%) was significantly higher (P<0.001) compared to those with elevated PFI but not on SU (76.9%). Multivariable-adjusted odds of decreased OCS risk given SU exposure was; OR (95%CI): 1.3791 (1.1458-1.6698), P=0.0007. Similarly, multivariable-adjusted odds of elevated PF risk in the light of SU exposure was; OR (95%CI): 1.4286 (1.1617-1.7567), P=0.0007. Furthermore, the JN significance regions for moderated regression analyses of odds of decreased OCS risk was between 10.4years [OR (95%CI): 0.5820 (0.1411-1.0228), P=0.0097] and 16.7years [OR (95%CI): 0.3025 (0.0001-0.6050), P=0.0500].

CONCLUSION

Adolescents on SU are about one and half times at risk of psychosocial dysfunction and age significantly attenuated the SU-decreased OCS risk link particularly in early adolescence.

College student knowledge of blackouts and implications for alcohol intervention: A qualitative analysis

Blackouts (periods of alcohol-induced anterograde amnesia) are common among young adults and place individuals at significant risk for alcohol-related harm; thus, researchers have advocated for increased efforts to educate young adults on blackouts. This qualitative study examined college student knowledge of blackouts as well as their ideas for intervening on blackout drinking behavior in order to inform prevention and intervention efforts. College students who had experienced a blackout in the past 6 months participated in eight focus groups, stratified by gender (N = 50, five to eight/group, 56% female). Discussions followed a semistructured agenda. Audio recordings were transcribed verbatim and coded using applied thematic analysis. Themes related to knowledge were reviewed in comparison to the empirical literature. Empirically derived risk factors for blackouts included biology (e.g., genetics, biological sex), drinking behavior (i.e., rate of consumption), other drug use, and "indirect" influences (e.g., pregaming, drinking location). Participants' knowledge of the risk factors for blackout was inconsistent and, in some cases, inaccurate. While participants generally understood the behavioral risk factors for blackouts, they demonstrated less understanding of the role of genetics, biological sex, drinking speed (vs. quantity), and other drug use. They also identified dehydration and sleep as perceived risk factors for blackout. They suggested avenues for intervention at the policy (e.g., amnesty policies), peer (e.g., expressing concern), and individual (e.g., education) levels. College students with a history of blackout have limited understanding of the biological risk factors for blackout. These knowledge gaps represent targets for intervention. Findings indicate promise for blackout-specific interventions. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Towards Standardizing the Alcoholism Evaluation Of Potential Liver Transplant Recipients

Aims

For teams around the world, alcoholic liver disease patients comprise the largest, and clinically most controversial, group applying for liver transplant. And yet evaluation decisions for them remain highly variable by locale.

Methods

Targeting standardized assessment, we provide guidelines on what information the transplant team should seek, from what sources, and how best to make use of it. This report focuses on 'what to do and how to do it' in providing appropriate assessments for this complex patient group.

Results

Proper evaluation includes (a) taking the clinical history from the patient and a required, corroborating third person, (b) assessing patient cognition, (c) establishing alcohol/substance use diagnosis to differentiate alcohol dependence, abuse and polysubstance dependence, (d) assessing ambivalence in primary alcohol addiction, (e) measuring social stability and (f) using Vaillant's factors for abstinence prognosis.

Conclusions

Properly applied, these six factors will allow standardized selection in most cases taken across programs despite differences in resources, available expertise and decision practices.

Short Summary

This report focuses on the essentials of the psychiatric/behavioral evaluation for 'alcoholic' persons referred for liver transplant. Attention to those essentials offers clinical standardization across transplant programs in different locales.

Distinctions in Alcohol-Induced Memory Impairment: A Mixed Methods Study of En Bloc Versus Fragmentary Blackouts

BACKGROUND

Blackouts-or memory loss for all or part of a drinking event-are reliable predictors of alcohol-related consequences. Studies suggest a distinction between en bloc (complete memory loss) and fragmentary (off-and-on memory loss) blackouts; however, research has not consistently differentiated between these 2 forms of blackout. This study aimed to validate the distinction between en bloc and fragmentary blackouts among young adults.

METHODS

Data were collected using qualitative (Study 1) and quantitative (Study 2) research methods. Participants in both studies were college students with a history of alcohol-induced memory impairment. They were recruited using community advertisement (Study 1, N = 50, 56% female) and Qualtrics survey panels (Study 2, N = 350, 56% female). Study 1 participants engaged in 8 focus groups. Discussions were audio-recorded, transcribed verbatim, and coded using applied thematic analysis. Findings guided assessment of en bloc and fragmentary blackout in Study 2. In Study 2, a separate sample of participants completed an online survey assessing drinking behavior, alcohol-induced memory impairment, and theoretical correlates of en bloc and fragmentary blackouts.

RESULTS

Study 1 participants differentiated between en bloc and fragmentary blackouts (which they referred to as "blackouts" and "brownouts," respectively) based on duration and extent of memory loss. They indicated that blackouts occur along a continuum, with en bloc "blackouts" at the extreme. They also stated that the term "blackout drinking" does not always imply memory loss. Study 2 participants reported higher rates of "brownouts" (81%) than "blackouts" (54%). They reported less negative outcome expectancies and attitudes, greater personal approval, higher prevalence estimates, lower self-efficacy, and stronger intentions for "brownouts" than "blackouts" (p < 0.001). Women perceived "blackouts/brownouts" as more prevalent than men and reported lower intentions to experience "blackouts" (p < 0.005).

CONCLUSIONS

Young adults are more permissive of fragmentary than en bloc blackout. En bloc blackouts may be a target for future interventions.

Binge Drinking and the Young Brain: A Mini Review of the Neurobiological Underpinnings of Alcohol-Induced Blackout

Binge drinking has significant effects on memory, particularly with regards to the transfer of information to long-term storage. Partial or complete blocking of memory formation is known as blackout. Youth represents a critical period in brain development that is particularly vulnerable to alcohol misuse. Animal models show that the adolescent brain is more vulnerable to the acute and chronic effects of alcohol compared with the adult brain. This mini-review addresses the neurobiological underpinnings of binge drinking and associated memory loss (blackout) in the adolescent and young adult period. Although the extent to which there are pre-existing versus alcohol-induced neurobiological changes remains unclear, it is likely that repetitive binge drinking in youth has detrimental effects on cognitive and social functioning. Given its role in learning and memory, the hippocampus is a critical region with neuroimaging research showing notable changes in this structure associated with alcohol misuse in young people. There is a great need for earlier identification of biological markers associated with alcohol-related brain damage. As a means to assess in vivo neurochemistry, magnetic resonance spectroscopy (MRS) has emerged as a particularly promising technique since changes in neurometabolites often precede gross structural changes. Thus, the current paper addresses how MRS biomarkers of neurotransmission (glutamate, GABA) and oxidative stress (indexed by depleted glutathione) in the hippocampal region of young binge drinkers may underlie propensity for blackouts and other memory impairments. MRS biomarkers may have particular utility in determining the acute versus longer-term effects of binge drinking in young people.

Predictors of Patterns of Alcohol-Related Blackouts Over Time in Youth From the Collaborative Study of the Genetics of Alcoholism: The Roles of Genetics and Cannabis

OBJECTIVE

Alcohol-related blackouts (ARBs) are anterograde amnesias related to heavy alcohol intake seen in about 50% of drinkers. Although a major determinant of ARBs relates to blood alcohol concentrations, additional contributions come from genetic vulnerabilities and possible impacts of cannabis use disorders (CUDs). We evaluated relationships of genetics and cannabis use to latent class trajectories of ARBs in 829 subjects from the Collaborative Study of the Genetics of Alcoholism (COGA).

METHOD

The number of ARBs experienced every 2 years from subjects with average ages of 18 to 25 were entered into a latent class growth analysis in Mplus, and resulting class membership was evaluated in light of baseline characteristics, including CUDs. Correlations of number of ARBs across assessments were also compared for sibling pairs versus unrelated subjects.

RESULTS

Latent class growth analysis identified ARB-based Classes 1 (consistent low = 42.5%), 2 (moderate low = 28.3%), 3 (moderate high = 22.9%), and 4 (consistent high = 6.3%). A multinomial logistic regression analysis within latent class growth analysis revealed that baseline CUDs related most closely to Classes 3 and 4. The number of ARBs across time correlated .23 for sibling pairs and -.10 for unrelated subjects.

CONCLUSIONS

Baseline CUDs related to the most severe latent ARB course over time, even when considered along with other trajectory predictors, including baseline alcohol use disorders and maximum number of drinks. Data indicated significant roles for genetic factors for alcohol use disorder patterns over time. Future research is needed to improve understanding of how cannabis adds to the ARB risk and to find genes that contribute to risks for ARBs among drinkers.

Sex and Drugs and Starting School: Differences in Precollege Alcohol-Related Sexual Risk Taking by Gender and Recent Blackout Activity

Research has demonstrated a link between alcohol use and multiple forms of risky sexual behavior, particularly among college-age individuals. Studies have also linked heavy alcohol use to other problems, such as impaired consciousness resulting from an alcohol-induced blackout, which may impact sexual decision making. However, research has rarely examined sexual risk taking (SRT) in relation to blackouts, nor has it examined this construct during the precollege transition (i.e., the interval of time between high school graduation and college matriculation). This study examined the intersection between alcohol-involved SRT, blackouts, and gender in a sample of precollege individuals with prior alcohol use (N = 229; 54% male, 63% White). Results indicated that, despite drinking less per occasion, women reporting recent blackouts were at increased risk for experiencing unwanted, unsafe, and regretted sexual behaviors compared to men with recent blackouts and their peers with no recent blackouts. Women with recent blackouts also reported differences in alcohol expectancies that may increase their risk for experiencing negative consequences while drinking, including higher social expectancies and lower negative expectancies of danger. Future directions for research and implications for precollege interventions are discussed.

Effects of drinking patterns on prospective memory performance in college students

OBJECTIVE

Traditional college students are at a critical juncture in the development of prospective memory (PM). Their brains are vulnerable to the effects of alcohol.

METHOD

There were 123 third and fourth year college students, 19-23 years old, who completed the Self-Rating Effects of Alcohol (SREA), Modified Timeline Follow-back (TFLB), Brief Young Adult Alcohol Consequences Scale (BYAACS), and Alcohol Effects Questionnaire (AEQ) once per month on a secure online database, as reported elsewhere (Dager et al., 2013). Data from the 6 months immediately before memory testing were averaged. In a single testing session participants were administered the Mini International Neuropsychiatric Interview-Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition-Text Revision (MINI-DSM-IV-TR), measures of PM (event-based and time-based), and retrospective memory (RM). Based on the average score of six consecutive monthly responses to the SREA, TLFB, and AEQ, students were classified as nondrinkers, light drinkers, or heavy drinkers (as defined previously; Dager et al., 2013). Alcohol-induced amnesia (blackout) was measured with the BYAACS.

RESULTS

We found a relationship between these alcohol use classifications and time-based PM, such that participants who were classified as heavier drinkers were more likely to forget to perform the time-based PM task. We also found that self-reported alcohol-induced amnesia (blackouts) during the month immediately preceding memory testing was associated with lower performance on the event-based PM task. Participants' ability to recall the RM tasks suggested the PM items were successfully encoded even when they were not carried out, and we observed no relationship between alcohol use and RM performance.

CONCLUSION

Heavy alcohol use in college students may be related to impairments in PM. (PsycINFO Database Record

Blackouts among male and female youth seeking emergency department care

BACKGROUND

Alcohol-related blackouts are a common consequence of heavy drinking, and these blackouts pose risk for injury and other adverse health outcomes.

OBJECTIVE

To examine the prevalence and correlates of blackouts among underage drinkers.

METHODS

Youth (ages 14-20) presenting to a suburban Emergency Department (ED) completed screening surveys. Among those reporting past-year alcohol consumption, we examined past 3-month blackouts in relation to: background characteristics (e.g., demographics, fraternity/sorority involvement), substance use, sexual risk behaviors and incapacitated sexual assault (unaware/unable to consent due to alcohol/drugs), forced sexual assault, positive depression screening, and reason for ED visit (injury vs. medical).

RESULTS

In total, 2,300 past-year drinkers participated: 58% female, 75% Caucasian, and mean age = 18.4. Regarding past 3-month blackouts, 72.7% reported none, 19.3% reported monthly or less, and 8% reported monthly or more. Multivariate cumulative logit regression indicated that blackout frequency was positively associated with: college involvement in Greek life, alcohol use severity, prescription drug misuse, marijuana, screening positive for depression, incapacitated sexual assault, and a gender by alcohol use severity interaction.

CONCLUSION

With one-quarter of this clinical sample reporting recent blackouts, as well as the association between blackout frequency and health risk behaviors and other outcomes, findings underscore the need for programs focusing on substance use, depression, and preventing sexual assault. Interventions should also address poly-substance use and drinking motives. Although findings highlight how college students in Greek life may be at high risk for blackouts, many participants not in college also reported blackouts, suggesting that interventions in other settings are also needed.

Alcohol-related blackouts across 55 weeks of college: Effects of European-American ethnicity, female sex, and low level of response to alcohol

BACKGROUND

While high blood alcohol concentrations (BACs) are required for alcohol-related blackouts (ARBs), additional characteristics also contribute to the risk, including a person's ethnicity, sex, and phenotypes relating to heavier drinking. Few prospective studies of ARBs have evaluated how these additional characteristics interact.

METHOD

Data regarding 398 European American (EA), Asian and Hispanic students were extracted from a 55-week prospective study of different approaches to decrease heavy drinking among college freshmen. Information on past month ARB frequency was determined at 8 assessments. While controlling for the prior month maximum BAC and active education vs. control group assignment, the patterns and intensities of ARBs over time across ethnic groups were evaluated with ANOVA at each follow-up for the full sample, and then separately by sex and then by low vs. high levels of response to alcohol status (LR). The overall pattern of ARBs over time was evaluated with a 3 ethnic groups by 2 sexes by 2 LR status by 8 time points mixed-design ANOVA.

RESULTS

Higher rates of ARBs over time were associated with EA ethnicity, female sex and a low LR to alcohol, with the ethnic differences in ARBs most robust in females and drinkers with high LRs. Participation in education programs aimed at heavy drinking was associated with decreases in ARBs.

CONCLUSIONS

The data indicate that in addition to BACs achieved, propensities toward ARBs relate to complex interactions between additional risk factors, including ethnicity, sex, and LR status.

Adolescent Alcohol Exposure Persistently Impacts Adult Neurobiology and Behavior

Adolescence is a developmental period when physical and cognitive abilities are optimized, when social skills are consolidated, and when sexuality, adolescent behaviors, and frontal cortical functions mature to adult levels. Adolescents also have unique responses to alcohol compared with adults, being less sensitive to ethanol sedative-motor responses that most likely contribute to binge drinking and blackouts. Population studies find that an early age of drinking onset correlates with increased lifetime risks for the development of alcohol dependence, violence, and injuries. Brain synapses, myelination, and neural circuits mature in adolescence to adult levels in parallel with increased reflection on the consequence of actions and reduced impulsivity and thrill seeking. Alcohol binge drinking could alter human development, but variations in genetics, peer groups, family structure, early life experiences, and the emergence of psychopathology in humans confound studies. As adolescence is common to mammalian species, preclinical models of binge drinking provide insight into the direct impact of alcohol on adolescent development. This review relates human findings to basic science studies, particularly the preclinical studies of the Neurobiology of Adolescent Drinking in Adulthood (NADIA) Consortium. These studies focus on persistent adult changes in neurobiology and behavior following adolescent intermittent ethanol (AIE), a model of underage drinking. NADIA studies and others find that AIE results in the following: increases in adult alcohol drinking, disinhibition, and social anxiety; altered adult synapses, cognition, and sleep; reduced adult neurogenesis, cholinergic, and serotonergic neurons; and increased neuroimmune gene expression and epigenetic modifiers of gene expression. Many of these effects are specific to adolescents and not found in parallel adult studies. AIE can cause a persistence of adolescent-like synaptic physiology, behavior, and sensitivity to alcohol into adulthood. Together, these findings support the hypothesis that adolescent binge drinking leads to long-lasting changes in the adult brain that increase risks of adult psychopathology, particularly for alcohol dependence.

Correlates for psycho-active substance use among boarding secondary school adolescents in Enugu, South East, Nigeria

Background

Psycho-active substance use among adolescents is a national and global problem and its attendant effects on adolescents cannot be overemphasized.

The objectives of this study are to determine the prevalence and pattern of psychoactive substance use among adolescents; the substances involved and the extent of the problem in this locale.

Methods

This is a cross-sectional study that assesses the pattern of psychoactive substance use among secondary school adolescents in Enugu, south East, Nigeria. The study was carried out among adolescents attending six secondary boarding schools in Enugu metropolis of Enugu State of Nigeria.

The WHO Student Drug Use Questionnaire was adapted for this study.

Data were analyzed using the Statistical Package for Social Sciences program (SPSS), version 17. Chi-square and multivariate regression were used as a test of significance for qualitative variables. A p-value less than 0.05 were accepted as significant for each statistical test.

Results

Out of 900, a total of 896 respondents, comprising 400 and 82 boys (482) (53.8 %) and 400 and 14 girls (414) (46.2 %) completed the questionnaires. This gave a response rate of 99.6 %.

The study revealed that the prevalence of current use for psychoactive substances ranges from 0.4 to 34.9 % while that for life use ranges from 0.8 to 63.5 %. The least being cannabis and the most being kola nuts.

Kola nut is the most widely used psychoactive substance both for current use, past year use and the respondents’ life time use. It shows a lifetime prevalence of 63.5 % and a current use prevalence of 34.9 %.

More than half of the users of each of the psychoactive substances take it occasionally, using them on 1–5 days in a month. On the other hand, almost one-quarter of the users of each of the substances take it on 20 or more days in a month.

Conclusion

The study revealed that the prevalence of current use for psychoactive substances ranges from 0.4 to 34.9 % while that for life use ranges from 0.8 to 63.5 %. The least being cannabis and the most being kola nuts.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0615-9) contains supplementary material, which is available to authorized users.

Alcohol-Induced Blackouts: A Review of Recent Clinical Research with Practical Implications and Recommendations for Future Studies

BACKGROUND

Alcohol-induced blackouts, or memory loss for all or portions of events that occurred during a drinking episode, are reported by approximately 50% of drinkers and are associated with a wide range of negative consequences, including injury and death. As such, identifying the factors that contribute to and result from alcohol-induced blackouts is critical in developing effective prevention programs. Here, we provide an updated review (2010 to 2015) of clinical research focused on alcohol-induced blackouts, outline practical and clinical implications, and provide recommendations for future research.

METHODS

A comprehensive, systematic literature review was conducted to examine all articles published between January 2010 through August 2015 that focused on vulnerabilities, consequences, and possible mechanisms for alcohol-induced blackouts.

RESULTS

Twenty-six studies reported on alcohol-induced blackouts. Fifteen studies examined prevalence and/or predictors of alcohol-induced blackouts. Six publications described the consequences of alcohol-induced blackouts, and 5 studies explored potential cognitive and neurobiological mechanisms underlying alcohol-induced blackouts.

CONCLUSIONS

Recent research on alcohol-induced blackouts suggests that individual differences, not just alcohol consumption, increase the likelihood of experiencing an alcohol-induced blackout, and the consequences of alcohol-induced blackouts extend beyond the consequences related to the drinking episode to include psychiatric symptoms and neurobiological abnormalities. Prospective studies and a standardized assessment of alcohol-induced blackouts are needed to fully characterize factors associated with alcohol-induced blackouts and to improve prevention strategies.

Binge Drinking Associations with Patrons' Risk Behaviors and Alcohol Effects after Leaving a Nightclub: Sex Differences in the "Balada com Ciência" Portal Survey Study in Brazil

The purpose of the present study was to investigate the potential associations of binge drinking detected at the exit of nightclubs and risk behaviors and alcohol effects just after leaving the venue in a representative sample of Brazilian nightclub patrons according to sex. For this purpose, a portal survey study called Balada com Ciência was conducted in 2013 in the megacity of São Paulo, Brazil, using a two-stage cluster sampling survey design. Individual-level data were collected in 2422 subjects at the entrance and 1822 subjects at the exit of 31 nightclubs, and breath alcohol concentration (BrAC) was measured using a breathalyzer. The following day, 1222 patrons answered an online follow-up survey that included questions about risk behaviors and alcohol effects practiced just after leaving the nightclub. Weighted logistic regressions were used to analyze binge drinking associated with risk behaviors by sex. For both sexes, the most prevalent risk behaviors practiced after leaving a nightclub were drinking and driving (men=27.9%; women=20.4%), the use of illicit drugs (men=15.8%; women=9.4%) and risky sexual behavior (men=11.4%; women=6.8%). The practice of binge drinking increased the behavior of illicit drug use after leaving the nightclub by 2.54 times [95% CI: 1.26-5.09] among men who drank and increased the risk of an episode of new alcohol use by 5.80 times [95% CI: 1.50-22.44] among women who drank. Alcoholic blackouts were more prevalent among men [OR=8.92; 95% CI: 3.83-20.80] and women [OR= 5.31; 95% CI: 1.68-16.84] whose BrAC was equivalent to binge drinking compared with patrons with a lower BrAC. Public policies aiming to reduce patrons’ BrAC at the exit of nightclubs, such as staff training in responsible beverage service and legislation to prevent alcohol sales to drunk individuals, would be useful to protect patrons from the risk behaviors associated with binge drinking in nightclubs.

Alcohol-induced blackouts and maternal family history of problematic alcohol use

BACKGROUND

Consequences of heavy drinking include alcohol-induced blackouts, which are periods of amnesia for all or part of a drinking event. One risk factor for blackouts is family history of problematic alcohol use (FH+); however, research rarely distinguishes maternal from paternal FH+. The objective of this study was to examine whether maternal or paternal FH+ better predicts likelihood of experiencing blackouts than a general measure of overall FH+, and whether gender moderates this association.

METHOD

Participants (N=1164; 65.4% are female) were first-time college freshmen (age range=17-19) who participated in a 6-year, 10-assessment, longitudinal study in the United States. Alcohol-induced blackouts, the dependent measure, were dichotomized (yes/no) based on endorsement of memory problems after drinking using a single item during Years 4-6. FH+, captured at baseline, was coded if participants self-reported that their mother, father, or any of their four grandparents were a possible or definite problem drinker.

RESULTS

Overall, 773 (66.4%) participants reported experiencing blackouts during Years 4-6. Women were more likely to report blackouts than men; however, compared with women with a maternal FH+, men with a maternal FH+ were more than twice as likely to report blackouts.

DISCUSSION

Men appear to be more susceptible than women to the effects of a maternal FH+. Genetic and environmental explanations for this finding are discussed. In sum, these findings are an important step toward understanding a significant yet understudied negative consequence of heavy alcohol use.

Latent trajectory classes for alcohol-related blackouts from age 15 to 19 in ALSPAC

BACKGROUND

Alcohol-related blackouts (ARBs) are reported by ~50% of drinkers. While much is known about the prevalence of ARBs in young adults and their cross-sectional correlates, there are few prospective studies regarding their trajectories over time during mid-adolescence. This paper reports latent trajectory classes of ARBs between age 15 and 19, along with predictors of those patterns.

METHODS

Latent class growth analysis (LCGA) was used to evaluate the pattern of occurrence of ARBs across 4 time points for 1,402 drinking adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC). Multinomial regression analyses evaluated age-15 demography, substance-related items, externalizing characteristics, and estimated peer substance use as predictors of latent class membership.

RESULTS

ARBs were reported at age 15 in 30% and at age 19 in 74% of these subjects. Four latent trajectory classes were identified: Class 1 (5.1%) reported no blackouts; for Class 2 (29.5%), ARBs rapidly increased with age; for Class 3 (44.9%), blackouts slowly increased; and for Class 4 (20.5%), ARBs were consistently reported. Using Class 2 (rapid increasers) as the reference, predictors of class membership included female sex, higher drinking quantities, smoking, externalizing characteristics, and estimated peer substance involvement (pseudo R(2)  = 0.22).

CONCLUSIONS

ARBs were common and repetitive in these young subjects, and predictors of their trajectories over time involved multiple domains representing diverse characteristics.

Molecular and neurologic responses to chronic alcohol use

This chapter provides an overview of current knowledge on the molecular and clinical aspects of chronic alcohol effects on the central nervous system. This drug is almost ubiquitous, widely enjoyed socially, but produces a diverse spectrum of neurologic disease when abused. Acutely, alcohol interacts predominantly with γ-aminobutyric acid-A (GABA-A) and N-methyl-d-aspartate (NMDA) receptors, but triggers diverse signaling events within well-defined neural pathways. These events result in adaptive changes in gene expression that ultimately produce two major states: addiction and toxicity. Epigenetic modifications of chromatin could lead to long-lived or even transgenerational changes in gene expression, thus producing aspects of the heritability of alcohol use disorders (AUD) and long-term behaviors such as recidivism. The diverse clinical syndromes produced by chronic alcohol actions in the central nervous system reflect the molecular pathology and predominantly involve aspects of tolerance/withdrawal, selective vulnerability (manifest as central pontine myelinolysis, Marchiafava-Bignami disease), and additional environmental factors (e.g., thiamine deficiency in Wernicke-Korsakoff's syndrome). Additionally, deleterious aspects of chronic alcohol on signaling, synaptic transmission, and cell toxicity lead to primary alcoholic dementia. Genetically determined aspects of myelin structure and alcohol actions on myelin gene expression may be a prominent molecular mechanism resulting in a predisposition to, or causation of, AUD and multiple other neurologic complications of chronic alcohol. The dramatic progress made in understanding molecular actions of alcohol holds great promise for our eventual treatment or prevention of AUD and neurologic complications resulting from chronic alcohol abuse.

Atypical neural activity during inhibitory processing in substance-naïve youth who later experience alcohol-induced blackouts

BACKGROUND

Alcohol-induced blackouts are associated with the development of alcohol abuse and dependence, so it is important to consider potential neurobiological risk factors for experiencing this problem prior to the onset of substance use. This study examines whether neural activity during inhibitory processing might be atypical in substance-naïve youth who later experience alcohol-induced blackouts.

METHODS

We examined inhibitory processing during fMRI with a go/no-go task that requires withholding a prepotent response in substance-naïve youth who would later transition into heavy drinking (n=40) and youth who remain abstinent (n=20). After approximately 5 years of annual follow-up assessments, youth were classified as nondrinkers (n=20), and heavy drinking youth were classified as having experienced an alcohol-induced blackout (blackout+; n=20) or not (blackout-; n=20). Groups were matched on demographic variables, and youth who experienced blackouts were matched on follow-up substance use.

RESULTS

Prior to initiating substance use, blackout+ youth showed greater activation during inhibitory processing than nondrinkers and blackout- youth in frontal and cerebellar brain regions. Mean activation during correct inhibitory responses relative to go responses in the left and right middle frontal gyri at baseline predicted future blackout experience, after controlling for follow-up externalizing behaviors and lifetime alcohol consumption.

CONCLUSIONS

Substance-naïve adolescents who later experience alcohol-induced blackouts show increased neural effort during inhibitory processing, as compared to adolescents who go on to drink at similar levels but do not experience blackouts and healthy, nondrinking controls, suggesting a neurobiological vulnerability to alcohol-induced memory impairments.

Bottled memories: on how alcohol affects eyewitness recall

This study investigated how different doses of alcohol affected eyewitness recall. Participants (N = 126) were randomly assigned to three groups with different blood alcohol concentration (BAC), either a control group (mean BAC 0.00%, N = 42), a lower alcohol dose group (mean BAC 0.04%, N = 40), or a higher alcohol dose group (mean BAC 0.06%, N = 44). After consumption, participants witnessed a movie of a mock crime and were interviewed one week later. The main results showed that witnesses with the higher intoxication level recalled fewer details compared to witnesses with the lower intoxication level. The amount of alcohol consumed did not have an impact on the accuracy rate. No sex differences were found. The results are discussed in the light of past research. We conclude that more studies are needed before recommendations can be made to an applied setting.

Possible long-term effects of γ-hydroxybutyric acid (GHB) due to neurotoxicity and overdose

In several countries, including the Netherlands, the use of GHB seems to be rising. GHB is regarded by recreational users as an innocent drug without any side effects. Recently, the number of patients in treatment due to GHB addiction sharply increased. In addition, various studies report incidents following risky GHB use or GHB overdosing. Other sedative drugs, like ketamine and alcohol have been shown to result in unintended neurotoxic harm at the level of memory and cognitive function. As outlined in the present review, GHB and ketamine have a common mode of action, which suggests that GHB may also lead to similar neurotoxicity as ketamine. GHB overdosing, as well as binge drinking (and high ketamine doses), induce profound coma which is probably neurotoxic for the brain especially in the maturing brain of young adults. It is therefore advocated to investigate possible long-term neurotoxic effects in recreational GHB users e.g. by studying the residual effects on cognition and memory.

Alcohol-induced memory blackouts as an indicator of injury risk among college drinkers

BACKGROUND

An alcohol-induced memory blackout represents an amnesia to recall events but does not involve a loss of consciousness. Memory blackouts are a common occurrence among college drinkers, but it is not clear if a history of memory blackouts is predictive of future alcohol-related injury above and beyond the risk associated with heavy drinking episodes.

OBJECTIVE

To determine whether baseline memory blackouts can prospectively identify college students with alcohol-related injury in the next 24 months after controlling for heavy drinking days.

METHODS

Data were analysed from the College Health Intervention Project Study (CHIPS), a randomised controlled trial of screening and brief physician intervention for problem alcohol use among 796 undergraduate and 158 graduate students at four university sites in the USA and one in Canada, conducted from 2004 to 2009. Multivariate analyses used generalised estimating equations with the logit link.

RESULTS

The overall 24-month alcohol-related injury rate was 25.6%, with no significant difference between men and women (p=0.51). Alcohol-induced memory blackouts at baseline exhibited a significant dose-response on odds of alcohol-related injury during follow-up, increasing from 1.57 (95% CI 1.13 to 2.19) for subjects reporting 1-2 memory blackouts at baseline to 2.64 (95% CI 1.65 to 4.21) for students acknowledging 6+ memory blackouts at baseline. The link between memory blackouts and injury was mediated by younger age, prior alcohol-related injury, heavy drinking, and sensation-seeking disposition.

CONCLUSIONS

Memory blackouts are a significant predictor of future alcohol-related injury among college drinkers after adjusting for heavy drinking episodes.