Level of response to alcohol as a factor for targeted prevention in college students

Initial Results from a New College Substance Use Prevention Program Targeting Externalizing and Internalizing Traits

Objective: College students engage in high rates of risky substance use. Standard college prevention strategies focus on providing feedback about current substance use behaviors and harm reduction strategies but do not address the underlying genetically-influenced risk factors impacting these behaviors. We created an online Personalized Feedback Program (PFP) for college students that targets genetically-influenced externalizing and internalizing risk pathways and provides personalized recommendations and campus resources. College students received personalized feedback on four risk domains (Sensation Seeking, Impulsivity, Extraversion, and Neuroticism). Methods: An open trial (n = 300) was conducted at a large public university in spring of 2021 to assess initial responses to the PFP and evaluate intentions related to future substance use and campus resource use. Results: 81% of students in the open trial reported they enjoyed the Personalized Feedback Program. Participants reported intending to use significantly more campus resources after completing the PFP. Among participants that drank, 39% reported they intended to decrease their alcohol consumption and 41% reported they intended to decrease the number of times they get drunk after completing the PFP; these intentions to reduce use after completing the PFP are higher than rates found in previous studies. Conclusion: Preliminary data indicate that the Personalized Feedback Program may be a complementary method to enhance current college substance use prevention programs.

The collaborative study on the genetics of alcoholism: Sample and clinical data

The collaborative study on the genetics of alcoholism (COGA) is a multi-site, multidisciplinary project with the goal of identifying how genes are involved in alcohol use disorder and related outcomes, and characterizing how genetic risk unfolds across development and in conjunction with the environment and brain function. COGA is a multi-generational family-based study in which probands were recruited through alcohol treatment centers, along with a set of community comparison families. Nearly 18,000 individuals from >2200 families have been assessed over a period of over 30 years with a rich phenotypic battery that includes semi-structured psychiatric interviews and questionnaire measures, along with DNA collection and electrophysiological data on a large subset. Participants range in age from 7 to 97, with many having longitudinal assessments, providing a valuable opportunity to study alcohol use and problems across the lifespan. Here we provide an overview of data collection methods for the COGA sample, and details about sample characteristics and comorbidity. We also review key research findings that have emerged from analyses of the COGA data. COGA data are available broadly to researchers, and we hope this overview will encourage further collaboration and use of these data to advance the field.

Genome-wide association mapping of ethanol sensitivity in the Diversity Outbred mouse population

BACKGROUND

A strong predictor for the development of alcohol use disorder (AUD) is altered sensitivity to the intoxicating effects of alcohol. Individual differences in the initial sensitivity to alcohol are controlled in part by genetic factors. Mice offer a powerful tool to elucidate the genetic basis of behavioral and physiological traits relevant to AUD, but conventional experimental crosses have only been able to identify large chromosomal regions rather than specific genes. Genetically diverse, highly recombinant mouse populations make it possible to observe a wider range of phenotypic variation, offer greater mapping precision, and thus increase the potential for efficient gene identification.

METHODS

We have taken advantage of the Diversity Outbred (DO) mouse population to identify and precisely map quantitative trait loci (QTL) associated with ethanol sensitivity. We phenotyped 798 male J:DO mice for three measures of ethanol sensitivity: ataxia, hypothermia, and loss of the righting response. We used high-density MegaMUGA and GigaMUGA to obtain genotypes ranging from 77,808 to 143,259 SNPs. We also performed RNA sequencing in striatum to map expression QTLs and identify gene expression-trait correlations. We then applied a systems genetic strategy to identify narrow QTLs and construct the network of correlations that exists between DNA sequence, gene expression values, and ethanol-related phenotypes to prioritize our list of positional candidate genes.

RESULTS

We observed large amounts of phenotypic variation with the DO population and identified suggestive and significant QTLs associated with ethanol sensitivity on chromosomes 1, 2, and 16. The implicated regions were narrow (4.5-6.9 Mb in size) and each QTL explained ~4-5% of the variance.

CONCLUSIONS

Our results can be used to identify alleles that contribute to AUD in humans, elucidate causative biological mechanisms, or assist in the development of novel therapeutic interventions.

Behavioral response bias and event-related brain potentials implicate elevated incentive salience attribution to alcohol cues in emerging adults with lower sensitivity to alcohol

AIMS

This study used a behavioral approach-avoidance task including images of alcoholic beverages to test whether low sensitivity to alcohol (LS) is a phenotypical marker of a dispositional propensity to attribute bottom-up incentive value to naturally conditioned alcohol cues.

DESIGN, SETTING AND PARTICIPANTS

Experimental study with a measured individual difference variable at a university psychology laboratory in Missouri, MO, USA. Participants were 178 emerging adults (aged 18-20 years) varying in self-reported sensitivity to alcohol's acute effects.

MEASUREMENTS

Participants completed the alcohol approach-avoidance task while behavior (response time; RT) and the electroencephalogram (EEG) were recorded. Stimulus-locked event-related potentials (ERPs) provided indices of integrated (top-down and bottom-up) stimulus incentive value (P3 amplitude) and conflict between top-down task demands and bottom-up response propensities (N450 amplitude).

FINDINGS

Linear mixed models showed faster RT for 'alcohol-approach' relative to 'alcohol-avoid' trials for lower-sensitivity (LS) [mean_D  ± standard error_D (M_D  ± SE_D ) = 29.51 ± 9.74 ms, t₍₃₂₈₎  = 3.03, P = 0.003] but not higher-sensitivity (HS) individuals (M_D  ± SE_D  = 2.27 ± 9.33 ms, t₍₃₂₈₎  = 0.243, P = 0.808). There was enhanced N450 amplitude (response conflict) for alcohol-avoid relative to alcohol-approach trials for LS participants (M_D  ± SE_D  = 0.811 ± 0.198 μV, Z = 4.108, P < 0.001) and enhanced N450 amplitude for alcohol-approach relative to alcohol-avoid for HS participants (M_D  ± SE_D  = 0.419 ± 0.188 μV, Z = 2.235, P = 0.025). There was also enhanced P3 amplitude for alcohol-approach relative to alcohol-avoid for LS (M_D  ± SE_D  = 0.825 ± 0.204 μV, Z = 4.045, P < 0.001) but not HS (M_D  ± SE_D  = 0.013 ± 0.194 μV, Z = 0.068, P = 0.946).

CONCLUSIONS

Findings from a human laboratory study appear to support the notion that low sensitivity to alcohol indexes a propensity to attribute bottom-up incentive value to naturally conditioned alcohol cues.

Effects of alcohol sensitivity on alcohol-induced blackouts and passing out: An examination of the alcohol sensitivity questionnaire among underage drinkers

BACKGROUND

The role of alcohol sensitivity in the experience of blacking out and passing out has not been well established. Here, we examined the relation between individual differences in alcohol sensitivity (i.e., numbers of drinks required to experience various effects of alcohol) and reports of blacking out and passing out in the past year.

METHODS

Participants (925 healthy, underage college student drinkers) completed the Alcohol Sensitivity Questionnaire (ASQ) and reported on their past year blacking out and passing out experiences.

RESULTS

The fit of the ASQ's 2-factor structure was fair (CFI = 0.90, RMSEA = 0.09) in this sample of underage drinkers. In unadjusted models, higher ASQ scores (i.e., requiring more drinks to experience effects, indicating lower alcohol sensitivity) were associated with experiencing more blackouts (IRR = 1.68 [1.31-2.15]) and passing out (IRR = 2.25 [1.59-3.18]) in the past year. After controlling for typical consumption, however, higher ASQ scores were associated with fewer past-year blackouts (IRR = 0.76 [0.60-0.98]). Total ASQ scores moderated the relationship between typical alcohol consumption and blackout occurrence (interaction IRR = 0.96 [0.93-0.98]), but not passing out occurrence (interaction IRR = 0.95 [0.89-1.01]), with the quantity of alcohol consumed more strongly associated with blackout occurrence among higher-sensitivity than lower-sensitivity drinkers.

CONCLUSIONS

These findings are consistent with prior work suggesting that low sensitivity may act as a paradoxical risk factor for certain heavy drinking effects, contributing to higher levels of alcohol consumption and more frequent negative consequences while also conferring protection (relative to high-sensitivity peers) at a given level of alcohol exposure.

Alcohol Sensitivity as an Endophenotype of Alcohol Use Disorder: Exploring Its Translational Utility between Rodents and Humans

Alcohol use disorder (AUD) is a complex, chronic, relapsing disorder with multiple interacting genetic and environmental influences. Numerous studies have verified the influence of genetics on AUD, yet the underlying biological pathways remain unknown. One strategy to interrogate complex diseases is the use of endophenotypes, which deconstruct current diagnostic categories into component traits that may be more amenable to genetic research. In this review, we explore how an endophenotype such as sensitivity to alcohol can be used in conjunction with rodent models to provide mechanistic insights into AUD. We evaluate three alcohol sensitivity endophenotypes (stimulation, intoxication, and aversion) for their translatability across human and rodent research by examining the underlying neurobiology and its relationship to consumption and AUD. We show examples in which results gleaned from rodents are successfully integrated with information from human studies to gain insight in the genetic underpinnings of AUD and AUD-related endophenotypes. Finally, we identify areas for future translational research that could greatly expand our knowledge of the biological and molecular aspects of the transition to AUD with the broad hope of finding better ways to treat this devastating disorder.

Genome-wide association studies of the self-rating of effects of ethanol (SRE)

The level of response (LR) to alcohol as measured with the Self-Report of the Effects of Alcohol Retrospective Questionnaire (SRE) evaluates the number of standard drinks usually required for up to four effects. The need for a higher number of drinks for effects is genetically influenced and predicts higher risks for heavy drinking and alcohol problems. We conducted genome-wide association study (GWAS) in the African-American (COGA-AA, N = 1527 from 309 families) and European-American (COGA-EA, N = 4723 from 956 families) subsamples of the Collaborative Studies on the Genetics of Alcoholism (COGA) for two SRE scores: SRE-T (average of first five times of drinking, the period of heaviest drinking, and the most recent 3 months of consumption) and SRE-5 (the first five times of drinking). We then meta-analyzed the two COGA subsamples (COGA-AA + EA). Both SRE-T and SRE-5 were modestly heritable (h2 : 21%-31%) and genetically correlated with alcohol dependence (AD) and DSM-IV AD criterion count (rg : 0.35-0.76). Genome-wide significant associations were observed (SRE-T: chromosomes 6, rs140154945, COGA-EA P = 3.30E-08 and 11, rs10647170, COGA-AA+EA P = 3.53E-09; SRE-5: chromosome13, rs4770359, COGA-AA P = 2.92E-08). Chromosome 11 was replicated in an EA dataset from the National Institute on Alcohol Abuse and Alcoholism intramural program. In silico functional analyses and RNA expression analyses suggest that the chromosome 6 locus is an eQTL for KIF25. Polygenic risk scores derived using the COGA SRE-T and SRE-5 GWAS predicted 0.47% to 2.48% of variances in AD and DSM-IV AD criterion count in independent datasets. This study highlights the genetic contribution of alcohol response phenotypes to the etiology of alcohol use disorders.

Alcohol sensitivity in women after undergoing bariatric surgery: a cross-sectional study

BACKGROUND

Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), the most common bariatric surgeries performed worldwide, increase the risk to develop an alcohol use disorder. This might be due, in part, to surgery-related changes in alcohol pharmacokinetics. Another risk factor, unexplored within this population, is having a reduced subjective response to alcohol's sedative effects.

OBJECTIVES

To assess whether the alcohol sensitivity questionnaire (ASQ), a simple self-report measure, could pinpoint reduced alcohol sensitivity in the bariatric population.

SETTING

University medical centers in Missouri and Illinois.

METHODS

Women who had RYGB (n = 16), SG (n = 28), or laparoscopic adjustable gastric banding surgery (n = 11) within the last 5 years completed the ASQ for both pre- and postsurgical timeframes, and 45 of them participated in oral alcohol challenge testing postsurgery. Blood alcohol concentration (BAC) and subjective stimulation and sedation were measured before and for 3.5 hours after drinking.

RESULTS

In line with faster and higher peak BACs after RYGB and SG than laparoscopic adjustable gastric banding surgery (P < .001), postsurgery ASQ scores were more reduced from presurgery scores after RYGB/SG than after laparoscopic adjustable gastric banding surgery (-2.3 ± .3 versus -1.2 ± .2; P < .05). However, despite the dramatic changes in BAC observed when ingesting alcohol after RYGB/SG surgeries, which resulted in peak BAC that were approximately 50% above the legal driving limit, a third of these women felt almost no alcohol-related sedative effects.

CONCLUSIONS

Although RYGB/SG dramatically increased sensitivity to alcohol in all participants, meaningful interindividual differences remained. The ASQ might help identify patients at increased risk to develop an alcohol use disorder after surgery.

The Relationship Between Regional Cerebral Blood Flow Estimates and Alcohol Problems at 5-Year Follow-Up: The Role of Level of Response

BACKGROUND

Acute alcohol consumption is associated with temporarily increased regional cerebral blood flow (CBF). The extent of this increase appears to be moderated by individual differences in the level of response (LR) to alcohol's subjective effects. The low LR phenotype is a known risk factor for the development of alcohol problems. This study investigates how the low LR phenotype relates to the relationship between alcohol-related changes in CBF and alcohol problems 5 years later.

METHODS

Young adults (ages 18 to 25) were selected based on their LR to alcohol and underwent a neuroimaging protocol including arterial spin labeling and functional scans. These participants were recontacted ~5 years later and assessed on alcohol outcomes. A final sample of 107 subjects (54 low and 53 high LR subjects) was included in the analyses. Whole-brain analysis revealed 5 clusters of significant alcohol-induced, versus placebo-induced, CBF changes that were consistent with a previous report. Peak alcohol-placebo CBF response was extracted from these regions and, along with the LR group, submitted to a hierarchical linear regression predicting alcohol problems. Analyses controlled for age, sex, and baseline alcohol problems.

RESULTS

In the regression analysis, greater alcohol-placebo CBF difference in the right middle/superior/inferior frontal gyri and bilateral anterior cingulate gyri clusters predicted greater future alcohol problems for the low LR group, whereas this relationship was not found to be significant in the high LR group.

CONCLUSIONS

This study demonstrates a clinically important relationship between CBF and future alcohol problems, particularly in individuals with a low LR phenotype. These initial results help to elucidate the neurobiological pathways involved in the development of alcohol use disorders for individuals with low LR.

The Utility of a Brief Web-Based Prevention Intervention as a Universal Approach for Risky Alcohol Use in College Students: Evidence of Moderation by Family History

Background: Alcohol use on college campuses is prevalent and contributes to problems that affect the health, emotional wellbeing, and academic success of college students. Risk factors, such as family history of alcohol problems, predict future alcohol problems, but less is known about their potential impact on intervention effectiveness. The purpose of this study was to examine the effect of an intervention implemented in a non-randomized sample of drinking and non-drinking college freshmen.

Methods: Freshmen college students recruited for the intervention study (n = 153) completed a web-adaptation of the Brief Alcohol Screening and Intervention for College Students (BASICS) at the start of spring semester. We compared their 30-days post-intervention alcohol initiation, number of drinking days (DAYS), drinks per occasion (DRINKS), maximum drinks in 24 h (MAX24) and alcohol use disorder symptoms (AUDsx) to 151 comparison participants retrospectively matched on demographics and baseline alcohol use behaviors. We also tested baseline DRINKS, DAYS, AUDsx, MAX24, and parental family history (PFH) of alcohol problems as moderators of the effect of the intervention.

Results: At follow-up, intervention participants had lower rates of AUDsx than comparison participants, especially among baseline drinkers. Among participants drinking 3+ days/month at baseline, intervention participants showed fewer DAYS at follow-up than the comparison group participants. BASICS was also associated with a decreased likelihood of initiation among baseline non-drinkers. PFH significantly interacted with treatment group, with positive PFH intervention participants reporting significantly fewer AUDsx at follow-up compared to positive PFH comparison participants. We found no evidence for an effect of the intervention on DRINKS or MAX24 in our analyses.

Conclusions: Results suggest some indication that novel groups, such as non-drinkers, regular drinkers, and PFH positive students may experience benefits from BASICS. Although conclusions were limited by lack of randomization and short follow-up period, PFH positive and low to moderate drinking groups represent viable targets for future randomized studies.

A Critical Review of Methods and Results in the Search for Genetic Contributors to Alcohol Sensitivity

Attributes of alcohol sensitivity are present before alcohol use disorders (AUDs) develop, they predict those adverse alcohol outcomes, are familial in nature, and many are heritable. Whether measured by alcohol challenges or retrospective reports of numbers of drinks required for effects, alcohol sensitivity reflects multiple phenotypes, including low levels of alcohol response and alcohol-related stimulation. Identification of genes that contribute to alcohol sensitivity could help identify individuals carrying risks for AUDs through their alcohol responses for whom early intervention might mitigate their vulnerability. Such genes could also improve understanding of biological underpinnings of AUDs, which could lead to new treatment approaches. However, the existing literature points to a wide range of genetic mechanisms that might contribute to alcohol responses, and few such genetic findings have been widely replicated. This critical review describes the potential impact of the diverse methods used to study sensitivity on the diversity of genetic findings that have been reported, places the genetic variants mentioned in the literature into broader categories rather than isolated results, and offers suggestions regarding how to advance the field by interpreting findings in light of the methods used to select research subjects and to measure alcohol sensitivity. To date, the most promising results have been for GABA, glutamate, opioid, dopamine, serotonin, and cholinergic system genes. The more gene variants that can be identified as contributors to sensitivity the better future gene screening platforms or polygenic scores are likely to be.

Post-GWAS in Psychiatric Genetics: A Developmental Perspective on the "Other" Next Steps

As psychiatric genetics enters an era where gene identification is finally yielding robust, replicable genetic associations and polygenic risk scores, it is important to consider next steps and delineate how that knowledge will be applied to ultimately ameliorate suffering associated with substance use and psychiatric disorders. Much of the post-genome-wide association study discussion has focused on the potential of genetic information to elucidate the underlying biology and use this information for the development of more effective pharmaceutical treatments. In this review we focus on additional areas of research that should follow gene identification. By taking genetic findings into longitudinal, developmental studies, we can map the pathways by which genetic risk manifests across development, elucidating the early behavioral manifestations of risk, and studying how various environments and interventions moderate that risk across developmental stages. The delineation of risk across development will advance our understanding of mechanism, sex differences and risk and resilience processes in different racial/ethnic groups. Here, we review how the extant twin study literature can be used to guide these efforts. Together, these new lines of research will enable us to develop more informed, tailored prevention and intervention efforts.

Alcohol Misuse Across the Lifespan: Insights from Developmental Studies in Behavior Genetics

Alcohol misuse, one of today's greatest public health challenges, is a developmentally dynamic, complex behavior at the intersection of genetic and environmental influences. This review examines such influences from a behavior genetics perspective and discusses implications for public policy. Alcohol misuse is moderately heritable with genetic influences accounting for around 50% of its variance, but to date few specific genes have been identified. However, numerous environmental and social factors moderate genetic risk, including parents, peers, romantic partners, family dynamics, employment, laws, and cultural influences. These moderating factors change in salience across development, and, accordingly, no one-size-fits-all approach is suitable for reducing alcohol misuse at a large scale. We provide examples of some effective prevention and intervention programs and discuss a framework for using the behavior genetics evidence to inform future public policy efforts.

Mediation of effects of the level of response to alcohol and impulsivity 15 years later in 36-year-old men: Implications for prevention efforts

BACKGROUND

Although the prevalence of alcohol use disorders (AUDs) has increased in older individuals in the recent decade, there are few programs to mitigate that increase. The current analyses evaluate the feasibility of applying to older drinkers elements of an approach to prevent heavier drinking in young adults by focusing on mediators of effects of two risk factors for alcohol problems, low levels of response to alcohol (low LRs) and higher impulsivity.

METHODS

Data were extracted from the San Diego Prospective Study (SDPS). Structural Equation Models evaluated relationships among age 36 low LRs and higher impulsivity; age 46 perceived peer drinking, alcohol expectancies, and drinking to cope; and age 51 alcohol problems, even after controlling for age 36 alcohol problems.

RESULTS

Relationships of age 36 low LRs to later alcohol problems was both direct and linked to age 46 heavy drinking peers. LR also operated indirectly through peer drinking to alcohol expectancies and drinking to cope. Age 36 impulsivity had no direct path to later alcohol problems and operated primarily through mediation by alcohol expectancies and via expectancies to drinking to cope. After controlling for age 36 alcohol problems, the low LR and impulsivity results remained robust.

CONCLUSIONS

Programs for mitigating increases in alcohol problems in middle-age drinkers should consider identifying individuals with low LRs and/or higher impulsivity and implementing prevention approaches similar to a program used in young adults. The approach should emphasize some different mediators for older drinkers with low LRs and those with higher impulsivity.

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.