Neural and genetic correlates of binge drinking among college women

Risk Factors for Binge Drinking in Young Adulthood: The Roles of Aggregate Genetic Liability and Impulsivity-Related Processes

OBJECTIVE

Binge drinking is characterized by excessive alcohol use and is widespread in youth. We explore the relationship between binge drinking's risk factors by considering (a) aggregate genetic liability (polygenic risk score [PGS]) for alcohol use and problems and (b) impulsivity-related processes. We examined whether the associations between PGS and binge drinking were mediated by impulsivity, with a possible shared genetic liability between alcohol phenotypes and impulsivity.

METHOD

Participants were from the Avon Longitudinal Study of Parents and Children (N = 2,545). We evaluated PGS for alcohol use and problems and impulsivity-related processes (sensation seeking at age 18 and inhibition at age 24) and measured binge drinking frequency (24 years old) as the outcome. Correlations and structural equation models were used to test a hypothesized model of the relationships among these variables.

RESULTS

Higher binge drinking frequency was related to higher aggregate genetic liability for alcohol use and problems in both models (standardized betas = .055-.064, all ps < .009). We found an association between binge drinking and sensation seeking (standardized beta = .224, p < .0001) but not inhibition (standardized beta = -.015, p = .437). Although the association between binge drinking and PGS for alcohol use and problems was mainly direct, a proportion of the association with alcohol problems was mediated by sensation seeking (14.61%).

CONCLUSIONS

Targeting sensation seeking at the end of adolescence may be means to prevent binge drinking in adulthood, whereas considering the role of genetic factors may improve our understanding of at-risk youth.

Association between alexithymia and substance use: A systematic review and meta-analysis

Alexithymia has been associated with substance use, but the magnitude of the association has not been evaluated and sub-group differences, if any, are unknown. The aim of this meta-analysis is to systematically review the association between alexithymia and substance use (alcohol or illicit drugs). We identified studies through a systematic review of PubMed and Web of Science and obtained a total of 52 publications using the Toronto Alexithymia Scale-20 scale. Random effects meta-analysis was used to evaluate the overall and sub-group associations. Of the studies, 50 were cross-sectional and two longitudinal. Alexithymia was associated with any substance use (Cohen's d = 0.62, 95% confidence interval [CI] 0.49-0.76), with little difference between estimates for use of alcohol or illicit drugs. A stronger association was observed for the alexithymia dimension "Difficulty in Identifying Feelings" (d = 0.64, 95% CI = 0.47-0.81) and "Difficulty in Describing Feelings" (d = 0.44, 95% CI = 0.32-0.55) than for "Externally Oriented Thinking" (d = 0.19, 95% CI = 0.09-0.28). The association was stronger in studies with clinical patient populations (d = 0.83, 95% CI = 0.62-1.05) than in those investigating general or student populations, and in studies with a majority of male rather than female participants. These findings suggest a strong overall association between alexithymia and substance use and a very strong association among clinical patient populations. The association may be stronger with the emotion-related dimensions than with the cognition-related dimension of alexithymia. As nearly all the studies were cross-sectional, more longitudinal studies are needed.

Time perception and alcohol use: A systematic review

Attentional, executive, and memory processes play a pivotal role in time perception. As acute or chronic alcohol consumption influences these processes, it should also modify time perception. We systematically reviewed and critically assessed all existing studies on time perception among alcohol drinkers, following the PICOS procedure and PRISMA guidelines. We selected 31 articles, distributed across four populations (i.e., alcohol intoxication, binge/heavy drinking, severe alcohol use disorder [SAUD], and Korsakoff syndrome). Several studies suggested the overestimation or underestimation of time during alcohol intoxication. No direct effect of binge/heavy drinking was observed on time perception, while studies on SAUD reported conflicting results. Participants with Korsakoff syndrome exhibited globally impaired time perception and marked deficits in associated cognitive abilities. This systematic review suggests that alcohol consumption affects time perception only when specific cognitive processes are depleted. However, due to the methodological limitations related to existing studies, no firm conclusion can be drawn. Guidelines and perspectives to advance the field are proposed.

What really matters in binge drinking: A dominance analysis of binge drinking psychological determinants among University students

Introduction

Binge drinking (BD) is a public health concern, especially in young people. Multiple individual factors referring to different level of analyses - positional, inter-individual and intra-individual - are associated to BD. As they have mainly been explored separately, little is known about the psychological variables most associated with BD. This study, based on an integrative model considering a large number of variables, aims to estimate these associations and possible dominance of some variables in BD.

Methods

A sample of university students (N = 2851) participated in an internet survey-based study. They provided information on alcohol related variables (AUDIT, BD score), positional factors (sex, age), inter-individual factors (subjective norm, social identity, external motivations), and intra-individual factors (internal motivations, meta-cognitions, impulsivity and personality traits). The data were processed via a backward regression analysis including all variables and completed with a dominance analysis on variables that are significantly associated with BD intensity.

Results

The strongest variables associated with BD intensity were enhancement motives and drinking identity (average ΔR ² = 21.81%), followed by alcohol subjective norm and social motives (average ΔR ² = 13.99%). Other associated variables (average ΔR ² = 2,84%) were negative metacognition on uncontrollability, sex, coping motives, lack of premeditation, positive metacognition on cognitive self-regulation, positive urgency, lack of perseverance, age, conformity motives and loneliness.

Conclusion

Results offer new avenues at the empirical level, by spotting particularly inter-individual psychological variables that should be more thoroughly explored, but also at the clinical level, to elaborate new prevention strategies focusing on these specific factors.

Electroencephalographic signatures of the binge drinking pattern during adolescence and young adulthood: A PRISMA-driven systematic review

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Controls and binge drinkers (BDs) do not differ in their behavioral performance.

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BDs show increased neural activity during attention, working memory and inhibition.

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Augmented P3 amplitude in BDs was the most solid electrophysiological finding.

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Evidence does not support specific gender vulnerabilities to the effects of BD.

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Memory, emotional processing and decision-making processes need further exploration.

Research on neurophysiological impairments associated with binge drinking (BD), an excessive but episodic alcohol use pattern, has significantly increased over the last decade. This work is the first to systematically review –following PRISMA guidelines- the empirical evidence regarding the effects of BD on neural activity –assessed by electroencephalography- of adolescents and young adults. A systematic review was conducted in 34 studies (N = 1723). Results indicated that binge drinkers (BDs) showed similar behavioral performance as non/low drinkers. The most solid electrophysiological finding was an augmented P3 amplitude during attention, working memory and inhibition tasks. This increased neural activity suggests the recruitment of additional resources to perform the task at adequate/successful levels, which supports the neurocompensation hypothesis. Similar to alcoholics, BDs also displayed increased reactivity to alcohol-related cues, augmented resting-state electrophysiological signal and reduced activity during error detection –which gives support to the continuum hypothesis. Evidence does not seem to support greater vulnerability to BD in females. Replication and longitudinal studies are required to account for mixed results and to elucidate the extent/direction of the neural impairments associated with BD.

High Alcohol-Preferring Mice Show Reaction to Loss of Ethanol Reward Following Repeated Binge Drinking

BACKGROUND

Beyond yielding high blood ethanol (EtOH) concentrations (BECs), binge-drinking models allow examination of drinking patterns which may be associated with EtOH's rewarding effects, including front-loading and consummatory successive negative contrast (cSNC), a decrease in intake when only water is available to subjects expecting EtOH. The goals of the current study were to broaden our understanding of these reward-related behaviors during binge EtOH access in high alcohol-preferring (HAP) replicate lines (HAP2 and HAP3) of mice selectively bred to prefer alcohol. We hypothesized that both lines would show evidence of front-loading during binge EtOH access and that we would find a cSNC effect in groups where EtOH was replaced with water, as these results have been shown previously in HAP1 mice.

METHODS

HAP replicate 2 and replicate 3 female and male mice were given 2 hours of EtOH or water access in the home cage for 15 consecutive days using "drinking in the dark" (DID) procedures. Mice received the same fluid (either 20% unsweetened EtOH or water) for the first 14 days. However, on the 15th day, half of the mice from these 2 groups were provided with the opposite assigned fluid (EtOH groups received water and vice versa). Intake was measured in 1-minute bins using specialized sipper tubes, which allowed within-session analyses of binge-drinking patterns.

RESULTS

EtOH front-loading was observed in both replicates. HAP3 mice displayed front-loading on the first day of EtOH access, whereas front-loading developed following alcohol experience in HAP2 mice, which may suggest differences in initial sensitivity to EtOH reward. Consummatory SNC, which manifests as lower water intake in mice expecting EtOH as compared to mice expecting water, was observed in both replicates.

CONCLUSIONS

These findings increase confidence that defined changes in home cage consummatory behavior are driven by the incentive value of EtOH. The presence of cSNC across HAP replicates indicates that this reaction to loss of reward is genetically mediated, which suggests that there is a biological mechanism that might be targeted.

Selective breeding for high alcohol consumption and response to nicotine: locomotor activity, dopaminergic in the mesolimbic system, and innate genetic differences in male and female alcohol-preferring, non-preferring, and replicate lines of high-alcohol drinking and low-alcohol drinking rats

RATIONALE

There is evidence for a common genetic link between alcohol and nicotine dependence. Rodents selectively bred for high alcohol consumption/responsivity are also more likely to self-administer nicotine than controls.

OBJECTIVES

The experiments examined the response to systemic nicotine, the effects of nicotine within the drug reward pathway, and innate expression of nicotine-related genes in a brain region regulating drug reward/self-administration in multiple lines of rats selectively bred for high and low alcohol consumption.

METHODS

The experiments examined the effects of systemic administration of nicotine on locomotor activity, the effects of nicotine administered directly into the (posterior ventral tegmental area; pVTA) on dopamine (DA) release in the nucleus accumbens shell (AcbSh), and innate mRNA levels of acetylcholine receptor genes in the pVTA were determined in 6 selectively bred high/low alcohol consuming and Wistar rat lines.

RESULTS

The high alcohol-consuming rat lines had greater nicotine-induced locomotor activity compared to low alcohol-consuming rat lines. Microinjections of nicotine into the pVTA resulted in DA release in the AcbSh with the dose response curves for high alcohol-consuming rats shifted leftward and upward. Genetic analysis of the pVTA indicated P rats expressed higher levels of α2 and β4.

CONCLUSION

Selective breeding for high alcohol preference resulted in a genetically divergent behavioral and neurobiological sensitivity to nicotine. The observed behavioral and neurochemical differences between the rat lines would predict an increased likelihood of nicotine reinforcement. The data support the hypothesis of a common genetic basis for drug addiction and identifies potential receptor targets.

The involuntary nature of binge drinking: goal directedness and awareness of intention

Binge drinking represents a public health issue and is a known risk factor in the development of alcohol use disorders. Previous studies have shown behavioural as well as neuroanatomical alterations associated with binge drinking. Here, we address the question of the automaticity or involuntary nature of the behaviour by assessing goal‐directed behaviour and intentionality. In this study, we used a computational two‐step task, designed to discern between model‐based/goal‐directed and model‐free/habitual behaviours, and the classic Libet clock task, to study intention awareness, in a sample of 31 severe binge drinkers (BD) and 35 matched healthy volunteers. We observed that BD had impaired goal‐directed behaviour in the two‐step task compared with healthy volunteers. In the Libet clock task, BD showed delayed intention awareness. Further, we demonstrated that alcohol use severity, as reflected by the alcohol use disorders identification test, correlated with decreased conscious awareness of volitional intention in BD, although it was unrelated to performance on the two‐step task. However, the time elapsed since the last drinking binge influenced the model‐free scores, with BD showing less habitual behaviour after longer abstinence. Our findings suggest that the implementation of goal‐directed strategies and the awareness of volitional intention are affected in current heavy alcohol users. However, the modulation of these impairments by alcohol use severity and abstinence suggests a state effect of alcohol use in these measures and that top‐down volitional control might be ameliorated with alcohol use cessation.

Do alcohol-dependent patients show different neural activation during response inhibition than healthy controls in an alcohol-related fMRI go/no-go-task?

RATIONALE

Alcohol dependence is associated with impaired response inhibition and heightened cue reactivity towards alcohol-related stimuli. Several brain areas, but mainly prefrontal structures, have been linked to response inhibition in addiction. This study aimed at combining both aspects: salience of drug-associated cues and response inhibition using a go/no-go task with alcohol-associated stimuli during functional magnetic resonance imaging (fMRI).

OBJECTIVES

Nineteen abstinent alcohol-dependent patients (ADP) and 21 healthy control subjects (HC) were compared on blood oxygen level-dependent (BOLD) responses during successful inhibition of no-go stimuli and successful reactions to go stimuli.

RESULTS

ADP and HC did not significantly differ in their behavioural performance in the task. However, both groups performed worse during the inhibition of alcoholic-associated stimuli compared to neutral stimuli. On the neural level, ADP displayed enhanced BOLD activity relative to HC during successful response inhibition in several areas involved in visual processing, cognitive and impulse control, including occipital structures, anterior cingulate gyrus, medial frontal gyrus and medial orbitofrontal cortex.

CONCLUSIONS

We interpret these findings as a possible compensation strategy for impaired cognitive processing. Furthermore, the results underline the impact of salience of alcohol-related stimuli on response inhibition, which seems to affect both ADP and HC.

Binge Drinking of Ethanol during Adolescence Induces Oxidative Damage and Morphological Changes in Salivary Glands of Female Rats

This study investigates morphological and biochemistry effects of binge ethanol consumption in parotid (PG) and submandibular (SG) salivary glands of rats from adolescence to adulthood. Female Wistar rats (n = 26) received ethanol at 3 g/kg/day (20% w/v) for 3 consecutive days/week from the 35th until the 62nd day of life. Animals were treated in two periods: 1 week (G1) and 4 weeks (G2), with a control (treated with distilled water) and an ethanol group to each period. In morphological analysis, morphometric and immunohistochemistry evaluation for smooth muscle actin (αSMA), cytokeratin-18 (CK-18), and vimentin (VIM) were made. Biochemical changes were analyzed by concentration of nitrites and levels of malondialdehyde (MDA). The difference between groups in each analysis was evaluated by Mann-Whitney U test or Student's t-test (p ≤ 0.05). PG showed, at one week of ethanol exposure, lower CK-18 and α-SMA expression, as well as MDA levels. After four weeks, lower CK-18 and higher MDA levels were observed in PG exposed to ethanol, in comparison to control group. SG showed lower α-SMA expression after 1 and 4 weeks of ethanol exposure as well as higher MDA levels after 1 week. Ethanol binge consumption during adolescence promotes tissue and biochemical changes with only one-week binge in acinar and myoepithelial PG cells.

Personality profile of binge drinking in university students is modulated by sex. A study using the Alternative Five Factor Model

BACKGROUND

The prevalence of binge drinking (BD), found especially among young people, is increasing worldwide and has become an important social and health concern. We studied, for the first time, the personality profile, using the Alternative Five Factor Model, among university students with BD and healthy controls, taking into account the possible influence of sex.

METHODS

70 participants with BD (30 men) and 70 healthy controls (30 men) were included, selected to control for characteristics that are known to be related to BD (physical and mental disorders, consumption of other drugs, circadian rhythms), completed the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ).

RESULTS

The scores on Neuroticism-Anxiety and Impulsive Sensation-Seeking were higher in the BD group compared to the controls (p<0.001 in both cases). The higher scores in the BD group in Neuroticism-Anxiety are due to higher scores in the women's group (p=0.014), while those in Impulsive Sensation-Seeking are due to higher scores in the men's group (p=0.009), both in the Impulsivity and in the Sensation-Seeking subscales (p<0.045).

CONCLUSIONS

Sex could be a factor that modulates the endophenotype of drug dependence (impulsive and anxious personality) and the prevention and/or treatment programs for BD should include not only the management of the personality risk factors but also different tailored approaches according to sex.

Relative fluid novelty differentially alters the time course of limited-access ethanol and water intake in selectively bred high-alcohol-preferring mice

BACKGROUND

The influence of previous alcohol (ethanol [EtOH])-drinking experience on increasing the rate and amount of future EtOH consumption might be a genetically regulated phenomenon critical to the development and maintenance of repeated excessive EtOH abuse. We have recently found evidence supporting this view, wherein inbred C57BL/6J (B6) mice develop progressive increases in the rate of binge EtOH consumption over repeated drinking-in-the-dark (DID) EtOH access sessions (i.e., "front loading"). The primary goal of this study was to evaluate identical parameters in high-alcohol-preferring (HAP) mice to determine whether similar temporal alterations in limited-access EtOH drinking develop in a population selected for high EtOH preference/intake under continuous (24-hour) access conditions.

METHODS

Using specialized volumetric drinking devices, HAP mice received 14 daily 2-hour DID EtOH or water access sessions. A subset of these mice was then given 1 day access to the opposite assigned fluid on day 15. Home cage locomotor activity was recorded concomitantly on each day of these studies. The possibility of behavioral/metabolic tolerance was evaluated on day 16 using experimenter-administered EtOH.

RESULTS

The amount of EtOH consumed within the first 15 minutes of access increased markedly over days. However, in contrast to previous observations in B6 mice, EtOH front loading was also observed on day 15 in mice that only had previous DID experience with water. Furthermore, a decrease in the amount of water consumed within the first 15 minutes of access compared to animals given repeated water access was observed on day 15 in mice with 14 previous days of EtOH access.

CONCLUSIONS

These data further illustrate the complexity and importance of the temporal aspects of limited-access EtOH consumption and suggest that previous procedural/fluid experience in HAP mice selectively alters the time course of EtOH and water consumption.

Assessing the Validity of Participant-Derived Compared to Staff-Derived Values to Compute a Binge Score

AIMS

This study examined the validity of two methods of classifying binge drinkers.

METHODS

Adult drinkers (n = 166) completed the Alcohol Use Questionnaire (AUQ) and a Timeline Followback (TLFB) interview to characterize drinking during the past 28 days. Using Townshend and Duka's (2005) recommendations, answers on three AUQ items (average drinks per hour, number of times drunk within the prior 6 months and percentage of times drunk when drinking) were used to derive a binge score that was then used to classify drinkers as Binge, Non-Binge and Unclassifiable. Two methods for calculating binge scores were compared: (a) Participant-derived, using participants' answers on the 3 AUQ items; and (b) Staff-derived, staff used TLFB interview information to answer the 3 AUQ items. Additionally, Participant- and Staff-derived classifications were used to predict future drinking behaviors assessed by a second TLFB interview.

RESULTS

Participant- and Staff-derived binge scores had a low concordance rate. Staff-derived classifications were better than Participant-derived classifications at predicting future binge drinking behavior and identifying group differences in drinking behavior reported during the second TLFB interview (average drinks per hour, number of times drunk within the prior 6 months, and percentage of times drunk when drinking).

CONCLUSIONS

Classifying drinkers using staff-guided TLFB interview methods instead of self-reported participant generalizations of typical drinking habits better relates to real-world drinking. Classification schemes that rely on dichotomous categorization of drinkers (Binge vs. Non-Binge) may be missing individuals who engage in harmful patterns of drinking. A continuous scale or index characterizing problematic drinking may be more useful.