Binge Drinking, Cognitive Performance and Mood in a Population of Young Social Drinkers

Acute alcohol decreases performance of an instrumental response to avoid aversive consequences in social drinkers

BACKGROUND

Recent studies demonstrated that alcohol impairs inhibitory control of behavioural responses.

AIMS

We questioned whether alcohol via its disinhibiting effects would also impair the inhibition of an instrumental avoidance response in the presence of a safety signal.

DESIGN

Thirty-six moderate social drinkers were randomly allocated to receiving either alcohol (0.8 g/kg) or placebo before performing an instrumental avoidance procedure. White noise of 102 db was used as aversive outcome presented at a variable interval schedule in S+ trials, while no noise was presented in S- trials. An instrumental response (repeated space bar presses to avoid the noise presented at a variable interval) abolished the noise. The Stop Signal task and the affective Go/No-Go task were administered as inhibitory control tasks.

RESULTS

Alcohol did not change the avoidance response rate in the presence of S- (safety signal). However, participants under alcohol performed the avoidance response to a lower extent than placebo subjects in S+ trials. Alcohol impaired performance in the Stop Signal task and increased the number of commission errors in the affective Go/No-Go task. Conditioned attentional and emotional responses to the S+ as well as knowledge of stimulus-response outcome contingencies were not affected by alcohol.

CONCLUSIONS

Acute alcohol may decrease the motivation to avoid negative consequences and thus might contribute to risky behaviour and binge drinking.

Intermittent access to beer promotes binge-like drinking in adolescent but not adult Wistar rats

Teenagers are more likely than adults to engage in binge drinking and could be more vulnerable to long-term brain changes following alcohol abuse. We investigated the possibility of excessive adolescent drinking in a rodent model in which beer (4.44% ethanol vol/vol) is presented to adult and adolescent male Wistar rats. Experiment 1 tracked ad libitum beer and water consumption in group-housed rats from postnatal day (PND) 28-96. Rats consumed an average of 7.8 g/kg/day of ethanol during adolescence (PND 34-55) and this gradually declined to a lower level of intake in adulthood (PND 56-93) of 3.9 g/kg/day. In Experiment 2, beer was made available to both adolescent (PND 29+) and adult (PND 57+) rats for 2h each day in a custom-built "lickometer" apparatus over 75 days. Access to beer was provided either 1 day out of every 3 ("intermittent" groups) or every day ("daily" groups). Relative to body weight, adolescent rats consumed more beer than adult rats in these limited access sessions. Adolescents with intermittent access consumed more than adolescents with daily access, a "binge"-like effect that was not observed in adult groups and that disappeared in adulthood. After 3 months of daily or intermittent alcohol consumption, the preference for beer versus sucrose was assessed. Rats previously kept under an intermittent schedule displayed a higher preference for beer relative to 3% sucrose, but only when testing occurred after 2 days of abstinence. In Experiment 3, adolescent (PND 30-37) and adult (PND 58-65) rats were given 20-min access to beer and their blood alcohol concentrations (BACs) were assessed. Adolescent groups consumed more alcohol than adults and showed higher BACS that were typical of human "binge" drinking (>80 mg/dL). Despite this, the correlation between BAC and beer intake was similar in both age groups. Together these results show that the intermittent presentation of alcohol itself appears to have subtle long-lasting effects on the motivation to consume alcohol. The findings support the use of beer solutions in modeling binge-like patterns of human alcohol consumption in adolescent rats.

Binge drinking in young adults: Data, definitions, and determinants

Binge drinking is an increasingly important topic in alcohol research, but the field lacks empirical cohesion and definitional precision. The present review summarizes findings and viewpoints from the scientific binge-drinking literature. Epidemiological studies quantify the seriousness of alcohol-related problems arising from binge drinking, with a growing incidence reported in college-age men over the last 2 years. Experimental studies have found neurocognitive deficits for frontal lobe processing and working memory operations in binge-drinking compared with nonbinge alcohol drinkers. The findings are organized with the goals of providing a useful binge-drinking definition in the context of the empirical results. Theoretical implications are discussed on how binge drinking may alter neurophysiological and neurocognitive function.

Biochemical and neurotransmitter changes implicated in alcohol-induced brain damage in chronic or 'binge drinking' alcohol abuse

The brain damage, which occurs after either chronic alcoholization or binge drinking regimes, shows distinct biochemical and neurotransmitter differences. An excessive amount of glutamate is released into specific brain regions during binge drinking (in excess of 4- to 5-fold of the normal basal concentration) that is not evident during periods of excessive alcohol consumption in chronic alcohol abusers. Increases in glutamate release are only observed during the initial stages of withdrawal from chronic alcoholism ( approximately 2- to 3-fold) due to alterations in the sensitivities of the NMDA receptors. Such changes in either density or sensitivity of these receptors are reported to be unaltered by binge drinking. When such excesses of glutamate are released in these two different models of alcohol abuse, a wide range of biochemical changes occur, mediated in part by increased fluxes of calcium ions and/or activation of various G-protein-associated signalling pathways. Cellular studies of alveolar macrophages isolated from these two animal models of alcohol abuse showed enhanced (binge drinking) or reduced (chronic alcoholization) lipopolysaccharide (LPS)-stimulated NO release. Such studies could suggest that neuroadaptation occurs with the development of tolerance to alcohol's effects in both neurotransmitter function and cellular processes during chronic alcoholization that delay the occurrence of brain damage. In contrast, 'binge drinking' induces immediate and toxic effects and there is no evidence of an increased preference for alcohol as seen after withdrawal from chronic alcoholization.

Review. Cognitive and emotional consequences of binge drinking: role of amygdala and prefrontal cortex

Binge drinking is an increasingly recognized problem within the UK. We have studied the relationship of binge drinking to cognitive and emotional functioning in young adults, and have found evidence for increased impulsivity, impairments in spatial working memory and impaired emotional learning. Since in human studies it is difficult to understand whether such behavioural changes pre-date or are a consequence of binge drinking, we have also studied parallel behaviours in a rodent model, in which rats are exposed to intermittent episodes of alcohol consumption and withdrawal. In this model, and in parallel with our findings in human binge drinkers, and alcoholic patients who have undergone multiple episodes of detoxification, we have found evidence for impairments in aversive conditioning as well as increased impulsivity. These behavioural changes are accompanied by facilitated excitatory neurotransmission and reduced plasticity (long-term potentiation (LTP)) in amygdala and hippocampus. The impaired LTP is accompanied by both impaired associative learning and inappropriate generalization of previously learned associations to irrelevant stimuli. We propose that repeated episodes of withdrawal from alcohol induce aberrant neuronal plasticity that results in altered cognitive and emotional competences.

Light to moderate alcohol consumption is associated with S100beta and amyloid beta levels in healthy older adults

Heavy alcohol consumption has been associated with several adverse neurocognitive outcomes in older adults, though little is known about lower consumption levels. No study has investigated the associations between S100beta and amyloid beta (Abeta) serum levels (biomarkers that provide evidence of neurological pathology) and light to moderate alcohol consumption in healthy older adults without neurological conditions. Thirty-five healthy older adults underwent neuropsychological testing and fasting blood draw with subsequent serum S100beta and Abeta 1-40 level quantification. Increased S100beta levels were associated with increased frequency of alcohol consumption and increased total monthly consumption of alcohol. Increased Abeta levels were associated with increased quantity of alcohol consumption. Further work investigating possible mechanisms is needed, particularly longitudinal studies and studies employing neuroimaging.

Early alcohol experiences and adolescent mental health: a population-based study in Taiwan

In this study, we examine whether adolescent emotional and behavior problems vary by history of early alcohol experiences. A national sample of 6974 alcohol-naïve and 4337 alcohol-experienced youths aged 15-18 years were identified within the 2004 National Survey of Illegal Drug Use among Adolescents in Taiwan. Four alcohol experience groups were created based on recency and frequency of alcohol use: (1) naïve; never drank alcohol, (2) trial use; first and only consumption of alcohol occurred more than 6 months preceding the assessment, (3) past use; alcohol used on more than one occasion but had not had a drink in the 6 months prior to the assessment, and (4) current use; consumed alcohol more than once and drank within the 6 months preceding the interview. A Chinese adaptation of the Youth Self-Report (YSR) assessed eight behavior syndromes: withdrawn, anxious/depressed, somatic complaints, social problems, thought problems, attention problems, rule-breaking behavior, and aggressive behavior. Multivariate response models (GLM/GEE) were used to examine the relationship of alcohol experiences with emotional and behavior problems. Alcohol-using youth were more likely to experience several specific emotional or behavioral syndromes than their alcohol-naïve counterparts. For example, youth with a history of alcohol use had an estimated 30-60% increase in the odds of experiencing items within the aggressive behavior syndrome as compared with alcohol-naïve youth. The type of early alcohol involvement in adolescence may exert differential effects on emotions and behaviors expressed across and within syndromes; these may warrant distinctions in informing etiological research and preventive efforts.

Neurocognitive effects of alcohol hangover

Alcohol hangover is characterized by adverse physical and mental effects that occur the next morning after the intake of toxic doses of alcohol. One of the more relevant functional consequences of hangover is the cognitive and subjective impairment, which could be related to the high socioeconomic costs of alcohol consumption. Nevertheless, few studies have addressed the study of neurocognitive and subjective effects of hangover. The systematic and exhaustive study of neurocognitive and subjective effects has not been done. In the present work we briefly review the hangover impact, not only in the objective execution of attention, psychomotricity and memory tasks, but in the subjective state of the subjects as well. Moreover, we also highlight the methodology difficulties to study neurocognitive effects of hangover and suggest several aspects to take into account in future investigations.

The influence of alcohol on basic motoric and cognitive disinhibition

It has been proposed that alcohol weakens control processes, which in turn supports the occurrence of disinhibited behaviours. Two studies were run, in parallel (both with 32 participants) using a between-subject design to investigate any disinhibiting effects of a moderate dose of alcohol (0.6 g/kg compared to placebo), previously found to trigger increased desire for alcohol. Disinhibiting effects were tested on basic motoric and cognitive control processes, using a go/no-go (GNG) and the Stroop task (ST) respectively. Although a higher proportion of participants wanted more alcohol under the alcohol preload (priming effect), this effect was not found to be significant. In the GNG task, correct response latency (RL) decreased from baseline [P = 0.008] while number of incorrect hits increased [P = 0.030] irrespective of treatment, indicating the formation of a habit-like response and motoric disinhibition. Although error rate did not differ between groups, an interaction occurred with regard to erroneous RL: participants under alcohol became quicker, while those under placebo became slower [P = 0.014]. In the ST, those preloaded with alcohol made significantly more errors [P = 0.021] and were quicker to complete the task [P = 0.044] compared with those preloaded with placebo, indicating a strong alcohol effect on cognitive disinhibition. The data suggest that a moderate dose of alcohol, which induces priming to want more alcohol, had disinhibiting effects both on a basic motoric and a cognitive inhibitory task. Thus the idea that priming may be mediated by the disinhibitory effects of alcohol is supported.

The relationship between non-acute adolescent cannabis use and cognition

Research indicates that cannabis continues to be a popular illegal drug internationally. Furthermore, adolescent rates of use appear to be significant. Whilst the non-acute effect of cannabis use on adult cognition has been extensively researched, there has been less examination of adolescents. This study aimed to investigate the non-acute relationship between cannabis and cognitive function in a sample of adolescents with a continuum of cannabis use, taking into account additional predictor variables (psychiatric functioning, general functioning, demographics and other drug use). Seventy adolescents were recruited from clinical and community sources as well as through newspaper advertisements. After 12 hours abstinence from cannabis, adolescents completed a two-hour interview covering: demographics; alcohol and drug use history; drug use in the past 28 days; depression; further psychiatric functioning (including ADHD and Conduct Disorder); and cognitive functioning as measured by computerised tasks (CANTAB) and traditional pen and paper tests. Adolescents who were regular cannabis users (more than once a week) had a significantly poorer performance on four measures of cognitive function reflecting attention, spatial working memory and learning. Cannabis use remained an independent predictor of performance on the working memory and strategy measures after additional predictor variables were included in a multivariate regression analysis. The results suggest that aspects of adolescent cognitive function are independently related to the frequency of cannabis use beyond acute intoxication.

Effects of alcohol and combined marijuana and alcohol use during adolescence on hippocampal volume and asymmetry

BACKGROUND

Converging lines of evidence suggest that the hippocampus may be particularly vulnerable to deleterious effects of alcohol and marijuana use, especially during adolescence. The goal of this study was to examine hippocampal volume and asymmetry in adolescent users of alcohol and marijuana.

METHODS

Participants were adolescent (aged 15-18) alcohol (ALC) users (n=16), marijuana and alcohol (MJ+ALC) users (n=26), and demographically similar controls (n=21). Extensive exclusionary criteria included prenatal toxic exposure, left handedness, and psychiatric and neurologic disorders. Substance use, cognitive, and anatomical measures were collected after at least 2 days of abstinence from all substances.

RESULTS

Adolescent ALC users demonstrated a significantly different pattern of hippocampal asymmetry (p<.05) and reduced left hippocampal volume (p<.05) compared to MJ+ALC users and non-using controls. Increased alcohol abuse/dependence severity was associated with increased right>left (R>L) asymmetry and smaller left hippocampal volumes while marijuana abuse/dependence was associated with increased L>R asymmetry and larger left hippocampal volumes. Although MJ+ALC users did not differ from controls in asymmetry, functional relationships with verbal learning were found only among controls, among whom greater right than left hippocampal volume was associated with superior performance (p<.05).

CONCLUSIONS

Aberrations in hippocampal asymmetry and left hippocampal volumes were found for adolescent heavy drinkers. Further, the functional relationship between hippocampal asymmetry and verbal learning was abnormal among adolescent substance users compared to healthy controls. These findings suggest differential effects of alcohol and combined marijuana and alcohol use on hippocampal morphometry and the relationship between hippocampal asymmetry and verbal learning performance among adolescents.

Effects of dose and time on the ability of alcohol to prime social drinkers

Interoceptive drug cues, through associations with the drug's reinforcing properties, may act as conditioned stimuli and elicit conditioned responses. For instance, a dose of alcohol, given to alcohol-experienced people, can lead to an enhancement of alcohol drinking, a phenomenon known as the priming effect. The present study aimed to investigate the alcohol priming effect in non-dependent social drinkers with respect to the dose of alcohol preload and the time of testing after preload. Fifteen social drinkers participated in five daily consecutive sessions. On days 1 and 2 (training sessions), participants consumed a 500 ml beverage of either 0.6 g/kg of alcohol or placebo (50 ml aliquots) presented in 10 colour-coded cups. During days 3, 4 and 5 (testing sessions), a preload of placebo, 0.3 or 0.6 g/kg of alcohol was given (in randomized sequence) in 10 opaque colourless cups. Thirty, 60 and 90 min following the preload, participants responded to an imagery script referring to the drinks sampled at training including a question on the number of aliquots participants would consume from each of the drinks if given the opportunity (hypothetical choice). Participants completed questionnaires evaluating mood and alcohol desires at baseline (before the beverages were given) and after the hypothetical choice. The hypothetical choice showed significant interactions between dose and time: the greatest number of alcohol aliquots were wanted 30 min following the 0.6 g/kg dose of alcohol preload. Ratings from the Desires for Alcohol Questionnaire also showed that alcohol desires peaked 30 min following the 0.6 g/kg of alcohol preload. These data support previous evidence that priming with alcohol can occur and indicate that dose of, and time after preload might affect the strength of, the priming effect for alcohol-related behaviours.

Repeated withdrawal from ethanol spares contextual fear conditioning and spatial learning but impairs negative patterning and induces over-responding: evidence for effect on frontal cortical but not hippocampal function?

Repeated exposure of rats to withdrawal from chronic ethanol reduces hippocampal long-term potentiation and gives rise to epileptiform-like activity in hippocampus. We investigated whether such withdrawal experience also affects learning in tasks thought to be sensitive to hippocampal damage. Rats fed an ethanol-containing diet for 24 days with two intermediate 3-day withdrawal episodes, resulting in intakes of 13-14 g/kg ethanol per day, showed impaired negative patterning discrimination compared with controls and animals that had continuous 24-day ethanol treatment, but did not differ from these animals in the degree of contextual freezing 24 h after training or in spatial learning in the Barnes maze. Repeatedly withdrawn animals also showed increased numbers of responses in the period immediately before reinforcement became available in an operant task employing a fixed-interval schedule although overall temporal organization of responding was unimpaired. Thus, in our model of repeated withdrawal from ethanol, previously observed changes in hippocampal function did not manifest at the behavioural level in the tests employed. The deficit seen after repeated withdrawal in the negative patterning discrimination and over-responding in the fixed-interval paradigm might be related to the changes in the functioning of the cortex after withdrawal.

Gender differences in associations between depressive symptoms and patterns of substance use and risky sexual behavior among a nationally representative sample of U.S. adolescents

OBJECTIVE

This study uses a cluster analysis of adolescents, based on their substance use and sexual risk behaviors, to 1) examine associations between risk behavior patterns and depressive symptoms, stratified by gender, and 2) examine gender differences in risk for depression.

METHODS

Data are from a nationally representative survey of over 20,000 U.S. adolescents. Logistic regression was used to examine the associations between 16 risk behavior patterns and current depressive symptoms by gender.

RESULTS

Compared to abstention, involvement in common adolescent risk behaviors (drinking, smoking, and sexual intercourse) was associated with increased odds of depressive symptoms in both sexes. However, sex differences in depressive symptoms vary by risk behavior pattern. There were no differences in odds for depressive symptoms between abstaining male and female adolescents (OR = 1.07, 95% CI 0.70-1.62). There were also few sex differences in odds of depressive symptoms within the highest-risk behavior profiles. Among adolescents showing light and moderate risk behavior patterns, females experienced significantly more depressive symptoms than males.

CONCLUSIONS

Adolescents who engage in risk behaviors are at increased risk for depressive symptoms. Girls engaging in low and moderate substance use and sexual activity experience more depressive symptoms than boys with similar behavior. Screening for depression is indicated for female adolescents engaging in even experimental risk behaviors.

Previous experience of ethanol withdrawal increases withdrawal-induced c-fos expression in limbic areas, but not withdrawal-induced anxiety and prevents withdrawal-induced elevations in plasma corticosterone

RATIONALE

Increased anxiety is a characteristic of the acute ethanol withdrawal syndrome. Repeated exposure of rats to withdrawal from chronic ethanol increases sensitivity to seizures.

OBJECTIVES

We investigated whether repeated withdrawal experience increases withdrawal-induced anxiety and stress, and if it changes withdrawal-induced activation of related brain areas.

METHODS

Rats were chronically treated with an ethanol-containing liquid diet either for 24 days continuously (single withdrawal, SWD) or interspersed with 2x3-day withdrawal periods (repeated withdrawal, RWD), or with a control diet. Eight hours after ethanol withdrawal, anxiety-like behaviour was tested in the elevated plus-maze, blood corticosterone levels were measured, and expression level of markers of neuronal activity and plasticity, c-fos and zif268, was assessed.

RESULTS

Eight hours after ethanol withdrawal, SWD rats showed increased anxiety on the elevated plus-maze relative to control rats. Rats given previous withdrawal experiences did not show further increases in measures of anxiety. Corticosterone levels were elevated during withdrawal in SWD rats but not in RWD rats. RWD resulted in marked increases in c-fos expression in amygdala, hippocampus, nucleus accumbens and dorsolateral periaqueductal grey. In contrast, zif268 expression was not increased after RWD, and in central amygdala the marked increase in zif268 seen after SWD was absent after RWD.

CONCLUSIONS

The data suggest increased ability of withdrawal to activate neuronal circuits but reduced plasticity after RWD. We suggest parallels between the consequences of repeated ethanol withdrawal and repeated exposure to stress, and discuss implications of withdrawal for brain plasticity.

Repeated ethanol exposure and withdrawal impairs human fear conditioning and depresses long-term potentiation in rat amygdala and hippocampus

BACKGROUND

In rats, repeated episodes of alcohol consumption and withdrawal (RWD) impair fear conditioning to discrete cues.

METHODS

Fear conditioning was measured in human binge drinkers as the increased startle response in the presence of a CS+ conditioned to aversive white noise. Secondly, the ability of tone CSs, paired with footshock, to induce c-fos expression, a marker of neuronal activity, in limbic structures subserving emotion was studied in rats. Additionally, consequences of RWD on subsequent induction of long term potentiation (LTP) in external capsule/lateral amygdala and Schaffer collateral/hippocampus CA1 pathways were studied in rat brain slices.

RESULTS

Fear conditioning was impaired in young human binge drinkers. The ability of fear-conditioned CSs to increase c-fos expression in limbic brain areas was reduced following RWD, as was LTP induction. Rats conditioned prior to RWD, following RWD showed generalization of conditioned fear from the tone CS+ to a neutral control stimulus, and a novel tone.

CONCLUSIONS

Binge-like drinking impairs fear conditioning, reduces LTP, and results in inappropriate generalization of learned fear responses. We propose a mechanism whereby RWD-induced synaptic plasticity reduces capacity for future learning, while allowing unconditioned stimuli access to neuronal pathways underlying conditioned fear.