Development and initial validation of the alcohol-induced blackout measure

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.

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.

A latent profile analysis of blackout drinking behavior among young adults

BACKGROUND

Blackout drinking, or alcohol-induced memory loss during a drinking occasion, is associated with additional negative alcohol-related outcomes. Brief motivational interventions targeting higher-risk alcohol use behavior have largely ignored blackout drinking. Including personalized information on blackout drinking could maximize intervention impact. To move toward incorporating content on blackout drinking in prevention and intervention materials, it is imperative to understand individual-level differences in blackout drinking. The current study aimed to identify latent profiles of young adults based on blackout drinking experiences and to examine person-level predictors and outcomes associated with profile membership.

METHOD

Participants were 542 young adults (ages 18-30) who reported 1+ past-year blackout episodes. Fifty-three percent of participants were female and 64% identified as non-Hispanic/Latinx white.

RESULTS

Four latent profiles were identified based on blackout drinking frequency, blackout intentions, blackout expectancies, and age of first blackout: Low-Risk Blackout (35% of the sample), Experimental Blackout (23%), At-Risk Blackout (16%), and High-Risk Blackout (26%). Profiles varied by demographic, personality, and cognition- and alcohol-related behaviors. Notably, At-Risk and High-Risk Blackout profiles had the highest alcohol use disorder risk, most memory lapses and cognitive concerns, and highest levels of impulsivity traits.

CONCLUSIONS

Findings support the multifaceted nature of blackout drinking experiences and perceptions. Profiles were differentiated across person-level predictors and outcomes, which identify potential intervention targets and individuals at heightened alcohol-related risk. A more comprehensive understanding of the heterogeneity of blackout drinking characteristics may be useful for early detection and intervention of problematic alcohol use predictors and patterns among young adults.

Associations between blackout drinking and self-reported everyday cognition among young adults

INTRODUCTION

Blackout drinking, or alcohol-induced memory loss during at least some part of a drinking occasion, is common among young adults and associated with negative alcohol-related consequences. One potential unique effect of blackout drinking episodes could be prolonged, general difficulties forming new memories through impairments in encoding, storage, or retrieval. The current study examined preliminary associations between blackout drinking and self-reported everyday cognitive functioning (i.e., memory lapses, non-memory cognitive difficulties, cognitive concerns) among a sample of young adults. We also examined the moderating role of key factors linked to blackout drinking: gender and frequent simultaneous alcohol and cannabis use.

METHODS

Participants (N = 479; 53% women) were aged 18-30 who reported past-year blackout drinking. Participants completed an online survey through Qualtrics Panels.

RESULTS

More frequent blackout experiences were found to be significantly related to more memory lapses, more non-memory cognitive difficulties, and more cognitive concerns even after controlling for typical alcohol use behavior. Men and individuals reporting frequent simultaneous use indicated stronger relationships between blackout drinking frequency and cognitive outcomes.

DISCUSSION AND CONCLUSIONS

Findings add to the growing body of literature supporting the uniquely hazardous effects of blackout drinking and identify individuals at heightened risk of harms. Given that associations between blackout drinking frequency and everyday cognitive functioning were identified even among a young adult sample suggests that blackout drinking may be a risky behavior that links to poorer cognitive functioning.

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.

Prevalence and correlates of alcohol-induced blackout in a diverse sample of veterans

BACKGROUND

Alcohol-induced blackouts have been associated concurrently and prospectively with alcohol-related harm. Although rates of heavy drinking among military samples tend to be comparable or higher than rates among civilian samples, the prevalence and correlates of blackout in the military population are understudied.

METHODS

Veterans (N = 241, 29% female, 39% Black) reported on their alcohol consumption and mental health as part of a larger health-related study among veterans. In this secondary analysis, we tested theoretically and empirically informed predictors (gender, drinking quantity, and other drug use) and consequences [depression, posttraumatic stress disorder (PTSD)] of alcohol-induced blackout. Given the diversity of the sample, potential roles of racial/ethnic discrimination and drinking to cope in alcohol-induced blackout were also tested.

RESULTS

Past-year prevalence of alcohol-induced blackout was 53% among veterans who drank alcohol and 68% among those who screened positive for hazardous drinking. Everyday experience of racial discrimination was the strongest concurrent predictor of alcohol-induced blackout. Drinking quantity and use of other drugs were significant correlates only in bivariate models. Controlling for gender, race, drinking quantity, other drug use, and discrimination, blackout frequency was significantly associated with symptoms of depression, but not symptoms of PTSD. Both blackout and racial discrimination were associated with drinking to cope.

CONCLUSIONS

The prevalence and correlates of alcohol-induced blackout among veterans are largely consistent with those documented in civilian and young adult populations. Among racially diverse groups, racial discrimination may be more strongly associated with mental health symptoms than alcohol consumption or acute alcohol consequences such as blackout.

Gender, acculturation, and alcohol-related consequences among college students of color

OBJECTIVE

The present study examined if identification with mainstream American culture (acculturation) and heritage culture (enculturation) are differentially associated with blackouts and other drinking consequences among male and female college students of color.

PARTICIPANTS

Participants were college students (N = 150) who self-identified as a racial/ethnic minority and endorsed blackouts in the past year.

METHODS

Regression models were used to examine gender-by-acculturation/enculturation interaction effects on alcohol-induced blackout and other alcohol-related consequences.

RESULTS

While acculturation was not significantly associated with either drinking outcome, enculturation showed a significant relationship with blackout frequency. Gender moderated this relationship; greater enculturation was associated with increased blackout frequency among male but not female students.

CONCLUSIONS

The present findings suggest the importance of considering the interplay between enculturation and gender in understanding alcohol use among college students of color. Men who endorse high levels of enculturation may be at an increased risk of experiencing negative drinking-related consequences.

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.

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.

Assessing alcohol use in situ: Correlates of self-report vs. objective alcohol consumption

Associations between self-report and objective measurement of young adult alcohol use are weakened by excessive consumption levels; therefore, associations between correlates of alcohol use and consumption likely also differ by alcohol measurement. This study examined the extent to which correlates of heavy drinking measured via self-report are also indicators of heavy drinking measured objectively. Data were collected from 164 bar patrons (54% male; 73% White, 12% Black, 15% Other; 15% Hispanic) as they exited the bar. Participants completed an intercept survey including self-reported measures of drinking, demographics, and social-environmental factors. A breath alcohol concentration (BrAC) reading was also obtained using a handheld breathalyzer device. Correlations between two self-reported outcomes, number of drinks consumed prior to and at the bar, and BrAC were significant among those in the lowest quartile of BrAC readings, but largely non-significant at moderate and high BrAC levels. Intention to get drunk that night was a robust predictor of alcohol consumption across self-reported outcomes and BrAC. Social factors (presence of drinking peers, witnessing drunk others) were predictive of self-reported alcohol use but not BrAC. AUDIT-C score was the only additional alcohol behavior predictive of objectively measured alcohol use. Self-reported outcomes and BrAC, as well as their association with key correlates, diverge at high levels of intoxication, when preventive intervention is most needed. Implications for further research and alcohol prevention practice are discussed.

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.

Intentions and motives to experience alcohol-induced blackout among young adults in college

Blackouts are typically considered a negative consequence of alcohol use. Yet some college students report consuming alcohol with the intention of blacking out. This study examined intentions and motives for blackout drinking among young adults in college. College students with a past-year history of blackout (N = 350, 56% female, 73% White) completed an anonymous online survey. Descriptive statistics were used to examine the incidence of blackout intentions, and individuals who did and did not report future blackout intentions were then compared on drinking patterns, depressive symptoms, social norms, and outcome expectancies. Overall, 135 participants (39%) reported consuming alcohol in the past 30 days with the intention of losing memory of the night's events, and 107 (31%) reported blackout intentions in the next 30 days. When asked (via open text box) to indicate their motives for past blackout intentions, the majority of participants provided responses that fit with coping, social, or enhancement drinking motives. A larger proportion of men than women reported blackout intentions. As a group, those reporting future blackout intentions reported heavier, more frequent, and more problematic drinking, as well as more symptoms of depression and more positive (but not negative) outcome expectancies. A substantial subset of college students reporting a blackout in the past year also endorsed intentions to experience a blackout in the next 30 days. Given strong associations between intentions and subsequent behavior, interventions targeting blackout styles of drinking are warranted. The extent to which "blackout" drinking motives differ from traditional drinking motives is unclear. (PsycInfo Database Record (c) 2020 APA, all rights reserved).