The performance of elements of a 'level of response to alcohol'-based model of drinking behaviors in 13-year-olds

Interoception and alcohol: Mechanisms, networks, and implications

Interoception refers to the perception of the internal state of the body and is increasingly being recognized as an important factor in mental health disorders. Drugs of abuse produce powerful interoceptive states that are upstream of behaviors that drive and influence drug intake, and addiction pathology is impacted by interoceptive processes. The goal of the present review is to discuss interoceptive processes related to alcohol. We will cover physiological responses to alcohol, how interoceptive states can impact drinking, and the recruitment of brain networks as informed by clinical research. We also review the molecular and brain circuitry mechanisms of alcohol interoceptive effects as informed by preclinical studies. Finally, we will discuss emerging treatments with consideration of interoception processes. As our understanding of the role of interoception in drug and alcohol use grows, we suggest that the convergence of information provided by clinical and preclinical studies will be increasingly important. Given the complexity of interoceptive processing and the multitude of brain regions involved, an overarching network-based framework can provide context for how focused manipulations modulate interoceptive processing as a whole. In turn, preclinical studies can systematically determine the roles of individual nodes and their molecular underpinnings in a given network, potentially suggesting new therapeutic targets and directions. As interoceptive processing drives and influences motivation, emotion, and subsequent behavior, consideration of interoception is important for our understanding of processes that drive ongoing drinking and relapse.

Cross-sectional and prospective associations of drinking characteristics with scores from the Self-Report of the Effects of Alcohol questionnaire and findings from alcohol challenges

BACKGROUND

Data from 2 generations of participants in the San Diego Prospective Study (SDPS) were used to compare cross-sectional and prospective relationships of 5 measures of the low level of response (low LR) to alcohol to 2 key alcohol-related outcomes.

METHODS

The analyses used data from 373 SDPS male probands and 158 male and female offspring of these individuals to evaluate relationships of 5 LR measures to the prior 5-year maximum drinks per occasion and the number of 11 DSM-IV alcohol use disorder (AUD) criteria experienced. Probands' LR measures included responses to alcohol challenges administered 15 years previously, and ratings for both generations included measures of the number of standard drinks during four periods: the first five times of drinking (SRE-5), the prior three drinking months (SRE-3), the period of heaviest drinking (SRE-H), and a total average across all time frames (SRE-T). Analyses included zero-order correlations, correlations using covariates, and hierarchical multiple regression analyses.

RESULTS

All 5 LR measures were correlated with aspects of maximum drinks and the number of AUD criteria, but the most robust results were seen for SRE-3 and maximum drinks. Correlations were less consistent for SRE-5, a measure more closely related to outcomes in the offspring. Hierarchical regression analyses supported most of these conclusions and showed that alcohol challenge-based LRs added significant information regarding maximum drinks even when evaluated with SRE values. The close correlation between SRE-H and SRE-T argues against the need for studies to include both measures. The patterns of results were similar irrespective of whether covariates were included.

CONCLUSIONS

There were significant correlations of maximum drinks and the number of AUD criteria with findings from prior alcohol challenges and all SRE scores. Challenges and SRE reports are related but not identical LR measures. All SRE scores, including SRE-5, offered useful information regarding subsequent drinking behavior.

Transfer of incentive salience from a first-order alcohol cue to a novel second-order alcohol cue among individuals at risk for alcohol use disorder: electrophysiological evidence

BACKGROUND AND AIMS

In susceptible individuals, cues associated with drug use are theorized to take on incentive-motivational properties, including the ability to reinforce higher-order, drug-related associative learning. This study aimed to test this prediction among people varying in risk for alcohol use disorder.

DESIGN, SETTING AND PARTICIPANTS

Repeated-measures experiment with a measured individual difference variable at a University psychology laboratory in Missouri, USA. One hundred and six young adults (96 contributed complete data) were pre-selected to represent the upper and lower quartiles of self-reported sensitivity to alcohol's acute effects.

MEASUREMENTS

Participants completed a second-order Pavlovian conditioning paradigm in which an initially neutral visual cue (second-order conditional stimulus; CS2 ) predicted onset of an olfactory cue (first-order conditional stimulus; CS1 ). Olfactory cues were isolated from alcoholic beverages, sweets and non-comestible substances, each presumed to have a natural history of first-order conditioning. Event-related potential responses to the CS2 across its conditioning and extinction, and to the CS1 , provided neurophysiological indices of incentive salience (IS).

FINDINGS

The IS of the alcohol CS1 was higher among participants low in alcohol sensitivity (LS), relative to their higher-sensitivity (HS) peers. The IS of the CS2 paired with the alcohol CS1 increased across the CS2 conditioning phase among LS but not HS participants. Also, LS (but not HS) individuals also experienced increases in alcohol craving following alcohol CS1 exposure, and this change was correlated with increases in the IS of the CS2 paired with the alcohol CS1 .

CONCLUSIONS

Alcoholic beverage odor, a proximal cue for alcohol consumption, appears to reinforce conditioning of neurophysiological responses to a novel cue among low alcohol sensitivity (LS) individuals but not high alcohol sensitivity individuals, providing the first evidence that the LS phenotype may be associated with differences in the conditioned reinforcing properties of alcohol-related cues. These findings support the idea that the LS phenotype may increase alcohol use disorder risk via susceptibility to incentive salience sensitization.

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.

Getting to the Heart of Low Sensitivity to Alcohol: Context Moderates Low Cardiovascular Response to Alcohol in Persons With a Family History of Alcohol Use Disorder

Background

Low sensitivity to alcohol in persons with a family history of alcoholism (FH+), compared to those without (FH−), contributes to risk for alcohol use disorder (AUD). However, sensitivity of FH+ cardiovascular response to alcohol is not well understood. This gap is significant because cardiovascular processes contribute to emotional regulation and stress response problems theorized to be central to the development and persistence of AUD. This study compared changes in heart rate (HR) and HR variability (HRV) between FH groups after consuming alcohol and control beverages and examined how these changes were moderated by emotional and alcohol‐related contexts.

Methods

Young adults (N = 165) with FH+ (n = 110) or FH− (n = 55) each completed 2 sessions, separated by 1 week. They received one of 3 different beverages (alcohol, placebo, and told‐no‐alcohol) in each session. Electrocardiogram data were recorded during pre–beverage consumption and post–beverage consumption baselines, and then during 4 picture cue tasks (neutral, positive, negative, and alcohol‐related). Generalized estimating equations were used to examine differences in cardiovascular reactivity (changes in HR and HRV power at ~ 0.1 Hz) across FH groups, beverage conditions, and picture cue tasks.

Results

A significant beverage condition × cue task × FH interaction effect on HRV was observed. The FH+ group, compared to the FH− group, showed (a) significantly less HRV suppression in specific cue contexts following alcohol, (b) a mixed pattern of more and less HRV suppression across cue contexts following placebo, and (c) a similar HRV reactivity pattern in the told‐no‐alcohol condition across cue tasks. For HR, there were no significant effects involving FH.

Conclusions

Diminished cardiovascular sensitivity to oral alcohol in FH+ persons varied within a given drinking episode depending on emotional and alcohol‐related features of the context, suggesting that environmental characteristics play a role in the expression of low sensitivity to alcohol among FH+ individuals.

Convergent Evidence From Humans and Drosophila melanogaster Implicates the Transcription Factor MEF2B/Mef2 in Alcohol Sensitivity

BACKGROUND

Self-Rating of the Effects of Alcohol (SRE) measures level of response to ethanol (EtOH) in humans. Interestingly, there is a positive relationship between the SRE and risk for abusing alcohol, suggesting mechanistic connections between SRE and alcohol abuse.

METHODS

To identify candidate genes with a role in SRE and alcohol-related behavior more generally, we coupled human genetic analyses with studies in Drosophila melanogaster. We first performed a gene-based analysis of Genomewide association studies (GWAS) summary statistics for SRE in the Avon Longitudinal Study of Parents and Children sample. Based on prior findings in humans, orthology to fly genes, and the availability of genetic reagents, we selected a subset of these genes for studies on EtOH behavior in Drosophila.

RESULTS

We found 37 genes with nominal associations in our SRE GWAS. We explored the role of 6 orthologous genes in Drosophila EtOH sedation and rapid tolerance. We found that the transcription factor Mef2 is required for normal EtOH sedation in flies. Pan-neuronal expression of 2 independent Mef2 RNAi transgenes significantly reduced Mef2 expression and made flies resistant to EtOH sedation. Additionally, flies with multiple independent mutant alleles of Mef2 were also resistant to EtOH sedation, confirming a role for Mef2 in this behavior. Altered expression of Mef2 did not change EtOH rapid tolerance or cause a net change in internal EtOH concentrations.

CONCLUSIONS

Our studies indicate that MEF2B influences SRE in humans and that Mef2 impacts EtOH sedation in Drosophila.

Meta-Analysis of Genetic Influences on Initial Alcohol Sensitivity

BACKGROUND

Previous studies indicate that low initial sensitivity to alcohol may be a risk factor for later alcohol misuse. Evidence suggests that initial sensitivity is influenced by genetic factors, but few molecular genetic studies have been reported.

METHODS

We conducted a meta-analysis of 2 population-based genome-wide association studies of the Self-Rating of the Effects of Alcohol scale. Our final sample consisted of 7,339 individuals (82.3% of European descent; 59.2% female) who reported having used alcohol at least 5 times. In addition, we estimated single nucleotide polymorphism (SNP)-based heritability and conducted a series of secondary aggregate genetic analyses.

RESULTS

No individual locus reached genome-wide significance. Gene and set based analyses, both overall and using tissue-specific expression data, yielded largely null results, and genes previously implicated in alcohol problems and consumption were overall not associated with initial sensitivity. Only 1 gene set, related to hormone signaling and including core clock genes, survived correction for multiple testing. A meta-analysis of SNP-based heritability resulted in a modest estimate of h SNP 2  = 0.19 (SE = 0.10), though this was driven by 1 sample (N = 3,683, h SNP 2  = 0.36, SE = 0.14, p = 0.04). No significant genetic correlations with other relevant outcomes were observed.

CONCLUSIONS

Findings yielded only modest support for a genetic component underlying initial alcohol sensitivity. Results suggest that its biological underpinnings may diverge somewhat from that of other alcohol outcomes and may be related to core clock genes or other aspects of hormone signaling. Larger samples, ideally of prospectively assessed samples, are likely necessary to improve gene identification efforts and confirm the current findings.

Alcohol-related blackouts among college students: impact of low level of response to alcohol, ethnicity, sex, and environmental characteristics

Objective:

To explore how a genetically-influenced characteristic (the level of response to alcohol [LR]), ethnicity, and sex relate to environmental and attitudinal characteristics (peer drinking [PEER], drinking to cope [COPE], and alcohol expectancies [EXPECT]) regarding future alcohol-related blackouts (ARBs).

Methods:

Structural equation models (SEMs) were used to evaluate how baseline variables related to ARB patterns in 462 college students over 55 weeks. Data were extracted from a longitudinal study of heavy drinking and its consequences at a U.S. university.

Results:

In the SEM analysis, female sex and Asian ethnicity directly predicted future ARBs (beta weights 0.10 and -0.11, respectively), while all other variables had indirect impacts on ARBs through alcohol quantities (beta weights ~ 0.23 for European American ethnicity and low LR, 0.21 for cannabis use and COPE, and 0.44 for PEER). Alcohol quantities then related to ARBs with beta = 0.44. The SEM explained 23% of the variance.

Conclusion:

These data may be useful in identifying college students who are more likely to experience future ARBs over a 1-year period. They enhance our understanding of whether the relationships of predictors to ARBs are direct or mediated through baseline drinking patterns, information that may be useful in prevention strategies for ARBs.

The natural expression of individual differences in self-reported level of response to alcohol during ecologically assessed drinking episodes

RATIONALE

Low sensitivity to alcohol is a well-established risk factor for alcohol use disorder (AUD). However, little is known about how the low sensitivity phenotype is expressed on a fine-grained, momentary level in drinkers' daily experience.

OBJECTIVES

The objective of the study is to evaluate individual differences in subjective states and appraisals of alcoholic beverages during the ascending limb of real-world drinking episodes.

METHODS

Social drinkers (N = 398) with varying degrees of alcohol sensitivity as indexed by the Self-Rating of the Effects of Alcohol form (SRE; Schuckit et al. in Addiction 92:979-988, 1997a) recorded diary entries over a 3-week monitoring period (2576 drinking episodes containing 6546 moments). Hierarchical linear modeling was used to evaluate whether individual differences in alcohol sensitivity predicted differing intra-episode estimated blood alcohol concentration (eBAC) trajectories, ratings of subjective states, and drink appraisals.

RESULTS

Lower self-reported alcohol sensitivity was associated with consuming "too much, too fast," as indicated by a steeper slope of ascending eBAC. In models adjusted for momentary eBAC level, participants reporting lower alcohol sensitivity at baseline showed blunted subjective intoxication and drink-contingent punishment.

CONCLUSIONS

The results suggest that low sensitivity to alcohol is associated with a blunting of some forms of subjective feedback (i.e., perceptions of intoxication and punishment) that might typically encourage drinking restraint. This may 'tip the scales' toward excess consumption and could help to explain why a low alcohol sensitivity forecasts AUD.

A prospective longitudinal model predicting early adult alcohol problems: evidence for a robust externalizing pathway

BACKGROUND

Risk factors for alcohol problems (AP) include biological and environmental factors that are relevant across development. The pathways through which these factors are related, and how they lead to AP, are optimally considered in the context of a comprehensive developmental model.

METHOD

Using data from a prospectively assessed, population-based UK cohort, we constructed a structural equation model that integrated risk factors reflecting individual, family and peer/community-level constructs across childhood, adolescence and young adulthood. These variables were used to predict AP at the age of 20 years.

RESULTS

The final model explained over 30% of the variance in liability to age 20 years AP. Most prominent in the model was an externalizing pathway to AP, with conduct problems, sensation seeking, AP at age 17.5 years and illicit substance use acting as robust predictors. In conjunction with these individual-level risk factors, familial AP, peer relationships and low parental monitoring also predicted AP. Internalizing problems were less consistently associated with AP. Some risk factors previously identified were not associated with AP in the context of this comprehensive model.

CONCLUSIONS

The etiology of young adult AP is complex, influenced by risk factors that manifest across development. The most prominent pathway to AP is via externalizing and related behaviors. These findings underscore the importance of jointly assessing both biologically influenced and environmental risk factors for AP in a developmental context.

Onset to First Alcohol Use in Early Adolescence: A Network Diffusion Model

A novel version of Snijders's stochastic actor-based modeling (SABM) framework is applied to model the diffusion of first alcohol use through middle school-wide longitudinal networks of early adolescents, aged approximately 11-14 years. Models couple a standard SABM for friendship network evolution with a proportional hazard model for first alcohol use. Meta-analysis of individual models for 12 schools found significant effects for friendship selection based on the same alcohol use status, and for an increased rate of onset to first use based on exposure to already-onset peers. Onset rate was greater at higher grades and among participants who spent more unsupervised time with friends. Neither selection nor exposure effects interacted with grade, adult supervision, or gender.

Sex differences in how a low sensitivity to alcohol relates to later heavy drinking

INTRODUCTION AND AIMS

A low level of response (LR), or low sensitivity, to alcohol is a genetically influenced characteristic that predicts future heavy drinking and alcohol problems. While previous analyses of how LR relates to heavier drinking reported the process is similar in males and females, some potential sex differences have been identified. This difference is further explored in these analyses.

DESIGN AND METHODS

Prospective structural equation models (SEMs) were evaluated for 183 young adult females and 162 males, none of Asian background, from the Collaborative Study on the Genetics of Alcoholism. Invariance analyses and SEM evaluations by sex were used to compare across females and males for these primarily Caucasian (75%), non-Asian young (mean age 19) subjects.

RESULTS

The prospective SEM for the full set of 345 subjects had good fit characteristics and explained 37% of the variance. While the initial invariance analyses identified few sex differences, comparisons of correlations and direct evaluations of path coefficients across males and females indicated that only females showed a link between a low LR and future alcohol problems that was partially mediated by more positive alcohol expectancies and drinking to cope. These sex differences were reflected in the different structures of the SEM results for female versus male subjects.

DISCUSSION AND CONCLUSIONS

These prospective results indicate that there might be some important sex differences regarding how a lower LR relates to alcohol outcomes that should be considered in protocols focusing on preventing the impact of LR on future drinking problems.

The relationship between childhood depressive symptoms and problem alcohol use in early adolescence: findings from a large longitudinal population-based study

AIMS

Depressive symptomatology can increase risk of development of alcohol problems in young people. Tension reduction and family interactional theories may explain the relationship between depression and problematic alcohol use in youth. This study addresses the nature of the longitudinal relationship between these two behaviours. The available literature is currently inconclusive about whether there are gender differences in these relationships; this is also examined.

DESIGN

The association between childhood depressive behaviours and adolescence problematic alcohol use was examined using ordered logistic regression models. Evidence of gender differences and the impact of relevant covariates on these relations were examined. Missing data were imputed using a Multiple Imputation by Chained Equation (MICE) approach.

SETTINGS

The Avon Longitudinal Study of Parents and Children (ALSPAC), a large UK population-based birth cohort.

PARTICIPANTS

A total of 4220 British boys and girls.

MEASUREMENTS

Depressive symptomatology was assessed in childhood (mean age = 10.6, SD = 0.2) using the Short Mood and Feelings Questionnaire (SMFQ). Problematic alcohol use was assessed from several questions queried in adolescence (mean age = 13.8, SD = 0.2).

FINDINGS

Childhood depressive symptoms were associated with increased risk of problematic alcohol use in early adolescence for girls [odds ratio (OR) = 1.14, P = 0.016] but not boys. This association for girls weakened (OR = 1.12, P = 0.058) when a priori selected covariates were taken into account, particularly the family and greater social environment.

CONCLUSIONS

Problematic alcohol use in girls (but not boys) is associated with prior depressive symptoms. This association may be attributable to several family and social environment factors, suggesting that a family interactional theoretical model may explain these findings.

Testing a level of response to alcohol-based model of heavy drinking and alcohol problems in 1,905 17-year-olds

BACKGROUND

The low level of response (LR) to alcohol is one of several genetically influenced characteristics that increase the risk for heavy drinking and alcohol problems. Efforts to understand how LR operates through additional life influences have been carried out primarily in modest-sized U.S.-based samples with limited statistical power, raising questions about generalizability and about the importance of components with smaller effects. This study evaluates a full LR-based model of risk in a large sample of adolescents from the United Kingdom.

METHODS

Cross-sectional structural equation models were used for the approximate first half of the age 17 subjects assessed by the Avon Longitudinal Study of Parents and Children, generating data on 1,905 adolescents (mean age 17.8 years, 44.2% boys). LR was measured with the Self-Rating of the Effects of Alcohol Questionnaire, outcomes were based on drinking quantities and problems, and standardized questionnaires were used to evaluate peer substance use, alcohol expectancies, and using alcohol to cope with stress.

RESULTS

In this young and large U.K. sample, a low LR related to more adverse alcohol outcomes both directly and through partial mediation by all 3 additional key variables (peer substance use, expectancies, and coping). The models were similar in boys and girls.

CONCLUSIONS

These results confirm key elements of the hypothesized LR-based model in a large U.K. sample, supporting some generalizability beyond U.S. groups. They also indicate that with enough statistical power, multiple elements contribute to how LR relates to alcohol outcomes and reinforce the applicability of the model to both genders.

A prospective evaluation of how a low level of response to alcohol predicts later heavy drinking and alcohol problems

BACKGROUND AND OBJECTIVES

Evaluations of how a genetically influenced characteristic, such as the low level of response (a low LR) to alcohol, relates to later heavy drinking and alcohol problems usually include environmental contributors. The best way to understand how LR works in the context of these additional characteristics is to study the process prospectively, but such analyses tend to be complex and the papers are sometimes cluttered with jargon. This report attempts to offer a more straightforward description of the results from such a prospective model of how a lower LR at age 20 relates to alcohol outcomes at age 40.

METHODS

A structural equation model of LR at age ∼20, outcomes of heavy drinking and problems at age ∼40, and additional characteristics at age ∼35 were tested in 378 men from the San Diego Prospective Study.

RESULTS

The results support both direct effects of age-20 LR on age-40 heavy drinking and alcohol problems, as well as indirect effects of LR through characteristics of these men at age 35. The latter include using alcohol to cope with stress and heavier drinking among peers.

CONCLUSIONS

A low LR to alcohol is an example of how both genes and environment can contribute to the risk for adverse alcohol outcomes. The identification of mechanisms through which LR impacts on later heavy drinking and problems can be approached in cross-sectional studies, but those may not be as sensitive as longitudinal models for identifying additional potential mediators of the LR-to-outcome relationship.

Self-Rating of the Effects of Alcohol (SRE): Predictive utility and reliability across interview and self-report administrations

The Self-Rating of the Effects of Alcohol (SRE) is a widely used and well-established measure of the level of response to alcohol. Although the SRE has been successfully used in studies of alcoholism etiology, including genetics, studies to date have not compared the self-report and interview formats. The objectives of this study are to: (a) test the predictive utility of the subscales of the SRE in relation to alcohol problems; and (b) test the reliability of the SRE in interview versus self-report formats. A sample of college drinkers (n=446) completed the SRE in a self-report format along with the Alcohol Use Disorders Identification Test (AUDIT). A subset of participants (n=34) returned to the laboratory and completed the SRE in a face-to-face interview format. All subscales of the SRE were robust predictors of alcohol problems accounting for as much as 25% of the variance in AUDIT scores. In addition, scores obtained via self-report and interview-based SRE were highly correlated (r=.70 to .80). Results support the predictive utility of the SRE and provide initial evidence that the self-report and interview formats produce reliable results and may be combined and/or used interchangeably.

Utilization of residential alcoholism treatment in bipolar disorder

Despite the high prevalence rate of comorbid alcohol dependence and bipolar disorder, little is known about how many bipolar patients are actively engaged in addiction treatment or the alcohol consumption characteristics of this group. This retrospective study reviewed the medical records from patients with alcohol dependence admitted to residential treatment at our institution (n = 588). The analyses focused on alcoholism severity measures and discharge clinical diagnoses. Patients with alcoholism + bipolar disorder compromised only 5% of the total study group. The number of drinking years was lower for patients with alcoholism + bipolar disorder (23.1 ± 17.7) than for those with alcoholism + depression (26.8 ± 13.9) or alcoholism alone (28.1 ± 13.2). A trend of higher mean lifetime maximum daily drinks was observed for patients with alcoholism + bipolar disorder; this was because of the significantly higher maximum drinks for women with bipolar disorder (21.0 ± 11.5) than for women in other diagnostic groups. Despite high rates of comorbidity in community-based studies, this retrospective study suggests that patients with bipolar disorder are not highly represented in residential alcoholism addiction treatment. Future studies are encouraged to better understand utilization rates of addiction treatment among patients with bipolar disorder and to identify clinical correlates that predispose bipolar women to high-dose drinking. 

Acute ethanol effects on brain activation in low- and high-level responders to alcohol

BACKGROUND

A low level of response (LR) to alcohol is an important endophenotype associated with an increased risk of alcoholism. However, little is known about how neural functioning may differ between individuals with low and high LRs to alcohol. This study examined whether LR group effects on neural activity varied as a function of acute alcohol consumption.

METHODS

A total of 30 matched high- and low-LR pairs (N = 60 healthy young adults) were recruited from the University of California, San Diego, and administered a structured diagnostic interview and laboratory alcohol challenge followed by two functional magnetic resonance imaging (fMRI) sessions under placebo and alcohol conditions, in randomized order. Task performance and blood oxygen level-dependent response contrast to high relative to low working memory load in an event-related visual working memory (VWM) task were examined across 120 fMRI sessions.

RESULTS

Both LR groups performed similarly on the VWM task across conditions. A significant LR group by condition interaction effect was observed in inferior frontal and cingulate regions, such that alcohol attenuated the LR group differences found under placebo (p < 0.05). The LR group by condition effect remained even after controlling for cerebral blood flow, age, and typical drinking quantity.

CONCLUSIONS

Alcohol had differential effects on brain activation for low- and high-LR individuals within frontal and cingulate regions. These findings represent an additional step in the search for physiological correlates of a low LR and identify brain regions that may be associated with the low LR response.

An evaluation of the full level of response to alcohol model of heavy drinking and problems in COGA offspring

OBJECTIVE

The low level of response (LR) to alcohol is an endophenotype related to heavier drinking and alcohol problems. Structural equation models (SEMs) indicate LR affects alcohol outcomes (ALCOUT) both directly and through mediation by drinking in peers (PEER), alcohol expectancies (EXPECT), and drinking to cope with stress (COPE), with some variation depending on the sample tested. This article presents the first full test of this LR-based model in young subjects from the Collaborative Study on the Genetics of Alcoholism (COGA).

METHOD

Data were generated from 325 12- to 22-year-old (47.4% male) drinking offspring from COGA families, using the Self-Report of the Effects of Alcohol questionnaire to determine LR early in the drinking career and a validated, structured interview for demography and alcohol use/problem patterns. Standardized questionnaires were used to measure PEER, EXPECT, and COPE, with the model tested through the maximum likelihood estimation for analyses of the variance/covariance matrix using both Amos and Mplus.

RESULTS

The SEM yielded good fit characteristics and explained 59% of the variance, with LR relating both directly to ALCOUT and as partially mediated by PEER and COPE. Although GENDER related to both LR and ALCOUT in the model, and AGE related to ALCOUT, the SEM results were invariant across both AGE and GENDER, with generally similar invariant results regarding the presence or absence of an alcohol-use disorder diagnosis.

CONCLUSIONS

The results support the applicability of the LR-based model of heavy drinking and alcohol problems in the COGA offspring, a group with different demography compared with the two other samples of adolescents tested to date. The modest differences observed across samples will be evaluated in future research to enhance understanding of how the model operates across socioeconomic groups.

The relationships of the level of response to alcohol and additional characteristics to alcohol use disorders across adulthood: a discrete-time survival analysis

BACKGROUND

A low level of response (LR) to alcohol has been shown to relate to a higher risk for alcohol use disorders (AUDs). However, no previous research has examined the association between LR and the development of AUDs in the context of additional robust risk factors for AUDs. This study evaluated whether LR and other related characteristics predicted the occurrence of AUDs across adulthood using discrete-time survival analysis (DTSA).

METHODS

A total of 297 probands from the San Diego Prospective Study reported on the LR to alcohol, a family history (FH) of AUDs, the typical drinking quantity, the age of drinking onset, the body mass index and the age at the baseline (T1) assessment. Alcohol use disorders (AUDs) were evaluated at the 10-year (T10), T15, T20, and T25 follow-ups.

RESULTS

A low LR to alcohol predicted AUD occurrence over the course of adulthood even after controlling for the effects of other robust risk factors. Interaction effects revealed that the impact of FH on AUDs was only observed for subjects with high T1 drinking levels, and probands with high T1 drinking were at high risk for AUDs regardless of their age of onset.

CONCLUSIONS

The findings illustrate that LR is a unique risk factor for AUDs across adulthood, and not simply a reflection of a broader range of risk factors. The continued investigation of how LR is related to AUD onset later in life will help inform treatment providers about this high-risk population, and future longitudinal evaluations will utilize DTSA to assess rates of AUD remission as well as the onset of drinking outcomes in adolescent samples.

The overlap in predicting alcohol outcome for two measures of the level of response to alcohol

BACKGROUND

Two different measures have been used to establish a person's level of response (LR) to alcohol as a risk factor for alcohol use disorders. LR values established by the alcohol challenge protocol and the Self-Report of the Effects of Ethanol (SRE) questionnaire usually correlate at 0.3 to 0.4, up to 0.6. However, it is not clear how this correlation relates to the ability of each measure to predict alcohol outcomes. This paper evaluates that overlap.

METHODS

Sixty-six Caucasian males (mean age = 22 years) from 2 protocols participated in alcohol challenges with 0.75 ml/kg of ethanol, filled out the SRE, and were followed with a structured interview approximately 5 years later. The relationship between the subjective feelings of intoxication at the time of peak breath alcohol levels from the alcohol challenge and the SRE score for a time early in the drinking career were evaluated regarding predicting the drinks per occasion in the 6 months prior to follow-up.

RESULTS

Cross-sectional correlations between alcohol challenge and SRE LR's ranged from -0.25 (p < 0.05) to -0.32 (p = 0.02) for the full sample, and the 2 LR measures correlated with drinking at follow-up (-0.26 and 0.41, respectively). The SRE measure was more robust than the challenge in a regression analysis predicting the outcome in the context of other baseline predictors (e.g., drinking at baseline). As much as 60% of the ability of the more well established (gold standard) alcohol challenge LR to predict outcome was shared with the SRE. The alcohol challenge accounted for as much as 44% of the ability of the SRE to predict outcome.

CONCLUSIONS

The SRE-generated LR overlapped considerably with the alcohol challenge LR in the ability to predict future heavier drinking.

The self-rating of the effects of alcohol questionnaire as a predictor of alcohol-related outcomes in 12-year-old subjects

AIMS

A low level of response (LR), or low sensitivity, to alcohol as established by alcohol challenges has been shown to predict future heavier drinking, alcohol-related problems and alcohol use disorders. To date, only one study has evaluated the predictive validity of a second measure of LR as determined by the Self-Report of the Effects of Alcohol (SRE) Questionnaire. The current analyses evaluate the ability of SRE scores as determined at age 12 to predict heavier drinking and alcohol-related problems 2 years later in a sample from the United Kingdom.

METHODS

The subjects were 156 boys (54.5%) and girls from the Avon Longitudinal Study of Parents and Children (ALSPAC) who had reported consuming one or more standard drinks by age 12 and who were followed up 2 years later.

RESULTS

The age 12 SRE scores correlated with the number of drinks per week, maximum drinks and the number of alcohol problems both at baseline and at age 14 follow-ups. In these evaluations, a larger number of drinks required for effects on the SRE (i.e. a lower LR per drink consumed) related to heavier intake and alcohol-related difficulties. Simultaneous entry multiple regression analyses revealed that the age 12 SRE score maintained a significant relationship with age 14 higher number of drinks per week and the number of alcohol problems even when the age 12 values for alcohol intake and problems were used as covariates.

CONCLUSION

The SRE scores appear to have value in predicting future heavier drinking and alcohol problems in 12-year olds that go beyond the information offered by the earlier drinking pattern alone.