Prospective Study Examining the Effects of Extreme Drinking on Brain Structure in Emerging 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.

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.

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

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

Alcohol use in emerging adults associated with lower rich-club connectivity and greater connectome network disorganization

BACKGROUND

Emerging adulthood is a critical neurodevelopmental stage, with alcohol use during this period consistently associated with brain abnormalities and damage in anatomical structure and white matter integrity. However, it is less clear how alcohol use is associated with the brain's structural organization (i.e., white matter connections between anatomical regions). Recent connectome research has focused on rich-club regions, a collection of highly-interconnected hubs that are critical in brain communication and global network organization and disproportionately vulnerable to insults.

METHODS

For the first time, we examined alcohol use associations with structural rich-club and connectome organization in emerging adults (N = 66).

RESULTS

Greater lifetime drinks and current monthly drinks were significantly associated with lower rich-club organization (r_s =-0.38, ps < 0.003) and lower rich-club connectivity (r_s <-0.34, ps < 0.007). Additionally, rich-club connectivity was significantly more negatively correlated with alcohol use than connectivity among non-rich-club regions (ps < 0.035). Examining overall structural organization, greater lifetime drinks and current monthly drinks were significantly associated with lower network density (i.e., lower network resilience; r_s <-0.36, ps = 0.004). Additionally, greater lifetime drinks and current monthly drinks were significantly associated with higher network segregation (i.e., network's tendency to divide into subnetworks; r_s >0.33, ps<0.008). Alcohol use was not significantly associated with network integration (i.e., network's efficiency in combining information across the brain; ps > 0.064).

CONCLUSIONS

Results provide novel evidence that alcohol use is associated with decreased rich-club connectivity and structural network disorganization. Given that both are critical in global brain communication, these results highlight the importance of examining alcohol use and brain relationships in emerging adulthood.

Prospective Study Examining the Effects of Extreme Drinking on Brain Structure in Emerging Adults

BACKGROUND

Emerging adulthood is a critical neurodevelopment period in which extreme drinking has a potentially pronounced neurotoxic effect. Therefore, extreme drinking, even a single episode, could be particularly harmful to the developing brain's structure. Relatedly, heavy alcohol use in emerging adults has been associated with structural brain damage, especially in the corpus callosum. However, it is unclear whether and how much a single extreme drinking episode would affect brain morphometry.

METHODS

For the first time in the literature, the current study prospectively examined the impact of an extreme drinking episode (i.e., twenty-first birthday celebration) on the brain morphometry of emerging adults immediately following their birthday celebration (n = 50) and approximately 5 weeks post-birthday celebration (n = 29).

RESULTS

We found evidence that a single extreme drinking episode was associated with structural changes immediately post-birthday celebration. Specifically, higher twenty-first birthday estimated blood-alcohol concentration was associated with decreased volume of the posterior and central corpus callosum immediately post-birthday celebration. This extreme drinking episode was not associated with further structural changes, or recovery, 5 weeks post-twenty-first birthday celebration.

CONCLUSIONS

Overall, results suggest that a single episode of heavy drinking in emerging adulthood may be associated with immediate structural changes of the corpus callosum. Thus, emerging adulthood, which is characterized by high rates of extreme drinking, could be a critical period for targeted prevention and intervention.