Trajectories of alcohol-induced blackouts in adolescence: early risk factors and alcohol use disorder outcomes in early adulthood

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.

Tracking Changes in the Endorsement of Injunctive Drinking Norms in Response to the COVID-19 Pandemic Using Longitudinal Alignment Analysis

The onset of the pandemic saw shifts in messaging around the acceptability of alcohol consumption at different times and contexts. A psychometric analysis of responses to injunctive norms may reveal important differences in specific aspects of norms that were influenced by the pandemic. Study 1 used alignment analysis to evaluate measurement invariance in low- and high-risk injunctive norms across samples of Midwestern college students from 2019 to 2021. Study 2 used an alignment-within-confirmatory factor analysis (CFA) approach to replicate the solution from Study 1 in an independent longitudinal sample (N = 1,148) who responded between 2019 and 2021. For Study 1, the latent mean for high-risk norms was significantly higher in 2021, and the endorsement of four specific norms also differed. In Study 2, increases in latent means for low- and high-risk norms were observed across 2020 and 2021, and differential endorsement emerged for one high-risk norm item. Examining scale-level changes in injunctive drinking norms provides insight into how college students' perceptions changed in response to the COVID-19 pandemic.

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.

Behavioral changes and dendritic remodeling of hippocampal neurons in adolescent alcohol-treated rats

Objective: Earlier, we and others have reported that alcohol exposure in adolescent rat impaired performance of a spatial memory task in the Morris water maze. The goal of the present study was to investigate the effects of acute adolescent alcohol treatment on the hippocampus-dependent (contextual fear conditioning) and hippocampus-independent (cued fear) memories. The study also looked at the structural changes in anterior CA1 hippocampal neurons in adolescent alcohol-treated rats. Methods: Adolescent female rats were administered with a single dose of alcohol (1.0, 1.5, or 2.0 g/kg) or vehicle either before training (pre-training) or after training (pre-testing). Experimental and control rats were trained in the fear conditioning paradigm, and 24 h later tested for both contextual fear conditioning as well as cued fear memory. Separate groups of rats were treated with either alcohol (2 g/kg) or vehicle and sacrificed 24 h later. Their brains were harvested and processed for rapid Golgi staining. Randomly selected CA1 pyramidal neurons were analyzed for dendritic branching and dendritic spine density. Results: Pre-training alcohol dose-dependently attenuated acquisition of hippocampus-dependent contextual fear conditioning but had no effect on the acquisition of amygdala-associated cued fear. When administered following training (pre-testing), alcohol did not alter either contextual conditioning or cued fear memory. Golgi stained CA1 pyramidal neurons in alcohol treated female rats had reduced basilar tree branching and less complex dendritic arborization. Conclusion: Alcohol specifically impaired hippocampal learning in adolescent rats but not amygdala-associated cued fear memory. Compared to vehicle-treated rats, CA1 hippocampal pyramidal neurons in alcohol-treated rats had less complex dendritic morphology. Together, these data suggest that adolescent alcohol exposure produces changes in the neuronal organization of the hippocampus, and these changes may be related to impairments in hippocampus-dependent memory formation.

Age and Fear of Missing Out as Moderators of the Association between Peak Drinks and Alcohol-Induced Blackouts among Adolescents and Young Adults

Background: Alcohol-induced blackouts are periods of impaired memory in which an individual is unable to recount events that occurred while they were intoxicated and are associated with heavier drinking episodes. Objectives: The present study examined age and Fear of Missing Out (FoMO) as moderators of the association between peak number of drinks and experiencing alcohol-induced blackouts. Participants ages 15-25 (N = 411; Mean age = 21.4 (SD = 2.5); 61.6% female) completed baseline and daily surveys as part of a larger ecological momentary assessment study. Past month blackout experiences and peak number of drinks were reported at baseline and FoMO was reported in daily surveys one to three weeks following the baseline survey. Results: A zero-inflated negative binomial model was fit to examine the interaction between peak number of drinks with age and FoMO on alcohol-induced blacking out, controlling for relevant covariates. Findings indicated the association between peak number of drinks on the likelihood of alcohol-induced blacking out was significantly moderated by age. The association was stronger for younger compared to older individuals. Findings further indicated the associations between peak number of drinks on both the likelihood and average number of alcohol-induced blacking out was significantly moderated by FoMO. For individuals with higher levels of FoMO, the association between peak drinks and alcohol-induced blacking out was weaker for the likelihood of experiencing any blackouts and stronger for the number of blackouts. Conclusions: Findings provide support to previous literature examining age and FoMO as risk factors for alcohol-induced blackouts among adolescents and young adults.

Insomnia as a moderator of alcohol use and blackout: Potential role in acute physiological consequences

BACKGROUND

Alcohol-induced blackout is associated concurrently and prospectively with alcohol-related harm, including emergency room visits and sexual coercion. Although sleep has not been linked empirically to blackout, symptoms of insomnia have also been linked to memory impairment, in which case insomnia symptoms may compound alcohol's negative effects on memory. This study tested insomnia symptoms as a moderator of the association between heavy drinking and alcohol-induced blackout.

METHODS

Heavy-drinking young adults in college (N = 461, 69% female) completed assessments online from remote locations. Hierarchical linear regression was used to test a moderation model predicting blackout frequency. Logistic regression was used to test post hoc hypotheses.

RESULTS

In contrast to our main hypothesis, heavy drinking was more weakly (not more strongly) associated with blackout in the context of more severe insomnia. Post hoc analyses tested insomnia symptoms as a unique moderator of the association between heavy drinking and likelihood of acute physiological consequences of alcohol use (blackout, passing out, nausea/throwing up, and hangover). Insomnia severity at least marginally moderated the association between heavy drinking and 4 out of 5 physiological consequences of alcohol use, and only moderated the association between drinking and 1 of 19 remaining consequences.

CONCLUSIONS

Symptoms of insomnia are associated with alcohol-related harm, but may buffer associations between drinking and acute physiological consequences of alcohol. Additional research is needed to determine if alcohol heightens sensitivity to the acute physiological effects of alcohol, in which case less alcohol may be required for young adults with insomnia to experience these effects.

The Use of Psychoactive Substances in Germany

BACKGROUND

Monitoring the use of psychoactive substances and substance-related problems in the population allows for the assessment of prevalence and associated health and social consequences.

METHODS

The data are derived from the Epidemiological Survey of Substance Abuse (ESA) 2021 (n = 9046, 18-64 years). We estimated prevalence rates of the use of tobacco, alcohol, illegal drugs, and psychoactive medications, as well as the prevalence rates of their problematic use (indicating dependence) using screening instruments, and extrapolated the results to the resident population (N = 51 139 451).

RESULTS

Alcohol was the most frequently used substance, with a 30-day prevalence of 70.5% (36.1 million people), followed by non-opioid analgesic drugs (47.4%; 24.2 million) and conventional tobacco products (22.7%; 11.6 million). E-cigarettes were used by 4.3% (2.2 million) and heat-not-burn products by 1.3% (665 000). Among illegal drugs (12-month prevalence), cannabis was the most frequently used (8.8%; 4.5 million), followed by cocaine/crack (1.6%; 818 000) and amphetamine (1.4%; 716 000). Rates of problematic use among the study participants were 17.6% for alcohol (9.0 million), 7.8% for tobacco (4.0 million), 5.7% for psychoactive medications (2.9 million), and 2.5% for cannabis (1.3 million).

CONCLUSION

The consumption of psychoactive substances continues to be widespread in Germany. In view of the imminent legal changes, the high prevalence of cannabis use and its problematic use need to be taken into consideration.

DSM-5 and ICD-11 alcohol use disorder criteria in young adult regular drinkers: Lifetime prevalence and age of onset

BACKGROUND

Alcohol Use Disorder (AUD) is a significant contributor to global disease burden. AUD has a relatively early onset during young adulthood (Teesson et al., 2010). However, compared to AUD in adults, we have relatively little understanding of AUD in adolescents and emerging adults.

METHODS

The RADAR study is a prospective cohort study designed to investigate the emergence of AUD in community-dwelling adolescents and emerging adults across Australia (age range = 18-21 at baseline). At 6 monthly intervals over 2.5 years, participants were interviewed regarding alcohol consumption and alcohol use disorder criteria by clinical psychologists using the SCID-IV-RV. This paper reports the baseline findings of the RADAR cohort.

RESULTS

Proportions of lifetime criteria endorsement among regular drinkers varied considerably. Tolerance was the most endorsed criterion (50.3%), followed by Social Problems (10.4%) and Larger/Longer (9.0%). The median age of onset for most individual AUD criteria was 18 years of age. 18.4% of our cohort met DSM-5 AUD diagnosis in their lifetime to date, and 16.8% met ICD-11 dependence. When removing Tolerance from the AUD criteria, DSM-5 AUD lifetime prevalence reduced to 11.0%, and ICD-11 AUD lifetime prevalence fell to 7.1% in our cohort.

CONCLUSIONS

Variable rates of criteria endorsement likely reflect both true differences in the experience of AUD criteria and methodological challenges in the assessment of AUD in an emerging adult age group. High rates of tolerance to the effects of alcohol, and relatively low rates of drinking larger/longer than intended are discussed considering methodological challenges in assessing these criteria in young adults.