The influence of alcohol on basic motoric and cognitive disinhibition

Latent classes of alcohol and cannabis use among adults with binge-spectrum eating disorders: Associations with eating disorder symptom severity and personality features

OBJECTIVE

Alcohol and cannabis use are prevalent among individuals with binge-spectrum eating disorders (B-ED) and vary in terms of frequency and associated problems. The current study aimed to identify latent classes of alcohol and cannabis use patterns among B-ED and examine associations between latent classes and demographic characteristics, eating disorder symptoms, and personality features.

METHODS

Participants (N = 236) were treatment-seeking adults with B-ED who completed a clinical interview of eating pathology and self-report measures of alcohol and cannabis use in the past 3 months, alcohol and cannabis-related problems, and personality features (i.e., impulsivity, affect lability).

RESULTS

Latent class analysis identified three heterogeneous classes, labelled as (a) Low Alcohol, (b) Moderate Drinking and Problems with Occasional Cannabis Use, and (c) No Alcohol and Cannabis Use. Latent classes significantly differed in terms of substance use engagement and problems, demographic characteristics, dietary restraint, impulsive personality features, and affect lability.

CONCLUSIONS

Study findings support heterogeneity in alcohol and cannabis use among B-ED and suggest patient characteristics and clinical severity associated with specific substance use presentations. Future research should replicate results using larger, diverse samples engaging in a broader range of alcohol and cannabis use symptoms.

Alcohol First, Cannabis Last: Identification of an Especially Risky Use Pattern among Individuals Who Co-Use Alcohol and Cannabis

Background: Alcohol and cannabis co-use is common and confers increased risk for potential harms, such as negative consequences and substance dependence. The existing evidence suggests that factors such as dose of delta-9-tetrahydrocannabinol (THC) consumed and order of use of each substance (i.e., using alcohol or cannabis first or last when co-using) may impact co-use outcomes. Existing co-use research has focused primarily on college-samples or young adults, and few studies have explored these nuanced relations among community samples. Methods: We examined survey data from 87 community members (mean age 32.9 years, 49.4% female) recruited from legal market cannabis dispensaries. Using a combination of regression techniques (i.e., OLS, negative binomial, censor-inflated) we modeled relations among co-use ordering patterns, THC dose and cannabis outcomes as well as interactions with sex assigned at birth and age. Results: Individuals who endorsed co-use reported significantly higher CUDIT scores than those who had never co-used (p < 0.01). Using alcohol first and cannabis last (a pattern we refer to as "AFCL") was more common among females than males (p < 0.01). In the context of typical substance use weeks, more frequently engaging in the AFCL pattern was associated with significantly higher CUDIT scores (p < 0.001) and negatively predicted positive consequences (p < 0.001). Other patterns predicted higher CUDIT scores during heavy use weeks. Conclusions: Results indicate that co-use ordering patterns are related to substance use outcomes. Further research leveraging within-subjects, longitudinal designs is needed to test causal relations between these variables.

Sexual alcohol expectancies moderate the relation between alcohol use and sexual behavior among men who have sex with men

BACKGROUND

HIV transmission remains a significant health concern for men who have sex with men (MSM) in the United States. Heavy episodic drinking (HED) is related to increased rates of condomless anal intercourse (CAI) among MSM, though evidence suggests that this association may vary by individual difference factors. The present secondary analysis tested whether sexual alcohol expectancies (SAEs) moderate the associations between frequency of HED and anal intercourse (AI) with and without a condom among moderate-to-heavy drinking HIV- MSM.

METHODS

Two hundred and forty-eight moderate-to-heavy drinking MSM completed self-report questionnaires including the Sexual Behavior Questionnaire, the Modified Daily Drinking Questionnaire, and the Sexual Alcohol Expectancies Questionnaire.

RESULTS

Negative binomial regressions indicated that SAEs moderated the association between frequency of HED and AI with a condom, but not between the frequency of HED and condomless AI (CAI).

CONCLUSIONS

These results suggest that stronger SAEs play a role in alcohol-related sexual behavior among MSM, but do not provide evidence that SAEs are associated with increased risk for HIV transmission through CAI.

The impact of sensation seeking personality trait on acute alcohol-induced disinhibition

BACKGROUND

Acute alcohol-related behavioral disinhibition has been well studied. But whether individual differences in the personality trait sensation seeking affect alcohol-induced behavioral disinhibition remains uncertain.

METHODS

The present study used functional near-infrared spectroscopy (fNIRS) technique and a response inhibition task (i.e., Go/No-Go) to determine the impact of the sensation seeking trait on the relationship between acute alcohol administration and inhibitory control capacity, and further investigate the neural mechanisms underlying this behavioral effect. Twenty-five high-sensation seekers and twenty-six low-sensation seekers were enrolled in this study. These participants attended two sessions: once for alcohol intake (0.5g/kg) and once for placebo intake (0g/kg).

RESULTS

Our results showed that high-sensation seekers relative to low-sensation seekers showed a significant decrease in inhibition accuracy under alcohol versus the placebo condition. Moreover, reduced prefrontal activity following acute alcohol consumption was more pronounced in high-sensation seekers compared with low-sensation seekers.

CONCLUSIONS

These findings showed that alcohol-induced behavioral disinhibition was affected by the personality trait sensation seeking and that recruitment of the prefrontal cortex contributed to the observed behavioral effect.

The association of alcohol use and positive and negative urgency to same day objective binge eating in emerging adults

Introduction

Objective binge eating and problematic alcohol use often co-occur and are common behaviors in emerging adults. Both behaviors are thought to be driven by affect regulation processes. Objective binge eating often occurs in the context of increasing or acute negative affect, and often occurs in solitude. Alcohol use in emerging adults can also be associated with negative affect regulation. However, in contrast to objective binge eating, a large body of research indicates that there are positively valenced pathways to alcohol use in this age group. Emerging adults often drink socially, to enhance enjoyment, and in the context of positive mood. We propose that one pathway to objective binge eating in this developmental period is through alcohol use itself, such that emerging adults who consume alcohol and who are more likely to act impulsively in the context of positive emotion (i.e., have high levels of positive urgency) may be more likely to binge eat following drinking.

Methods

We collected data using ecological momentary assessment in 106 undergraduates on positive and negative affect, motives for drinking and eating, and alcohol use and objective binge eating, in addition to baseline questionnaires of impulsivity.

Results

There were no significant changes in affect prior to drinking in this sample. Alcohol use at one time point significantly increased odds of objective binge eating at a later time point in the same day. Individual differences in positive urgency, the tendency to act rashly while experiencing positive affect, were also associated with increased odds of objective binge eating that occurred after alcohol use. Individual differences in negative urgency, the tendency to act rashly after experiencing negative affect, did not have a main effect on objective binge episodes, but did interact with alcohol use to increase the odds of objective binge eating following drinking. The vast majority of drinking episodes prior to objective binge eating were social drinking episodes, and participants most commonly endorsed "to have fun" as a reason for drinking.

Discussion

Results suggest that alcohol consumption may increase risk for objective binge eating in emerging adults.

Cognitive preoccupation with drinking and behavioral effects of alcohol as predictors of current consumption patterns

BACKGROUND

Acute alcohol responses such as tolerance to alcohol-induced motor impairment and heightened sensitivity to alcohol-induced disinhibition are associated with heavier drinking. Additionally, certain cognitive characteristics may also indicate problem-drinking. For example, cognitive and emotional preoccupation (CEP) with alcohol is associated with heavier drinking. However, it is not clear if cognitive markers have value as predicators of heavier drinking beyond that of well-established alcohol response markers. The current study sought to test the predictive potential of CEP in the context of two well-documented alcohol response markers of heavy drinking.

METHODS

Data aggregated from three studies comprised a sample of 94 young adult drinkers with no history of alcohol use disorder. Participants' motor coordination (grooved pegboard) and behavioral disinhibition (cued go/no-go) were assessed following consumption of 0.65g/kg alcohol and a placebo. CEP was measured via the Temptation and Restraint Inventory (TRI).

RESULTS

Drinkers who expressed both alcohol response markers reported drinking higher doses regardless of their level of CEP. Among drinkers who expressed low sensitivity to both disinhibition and motor impairment, higher CEP was associated with higher typical quantities. Low sensitivity to motor impairment functioned as a standalone marker of heavier drinking.

CONCLUSIONS

The findings suggest that a combination of tolerance to motor impairment and high alcohol-induced disinhibition may be sufficient to promote heavier consumption even in the absence of cognitive markers associated with problem drinking. Results also suggest that cognitive characteristics may drive early drinking and contribute to the development of tolerance to acute alcohol effects.

The impact of alcohol priming on craving and motivation to drink: a meta-analysis

BACKGROUND AND AIMS

An initial dose of alcohol can motivate-or prime-further drinking and may precipitate (re)lapse and bingeing. Lab-based studies have investigated the alcohol priming effect; however, heterogeneity in designs has resulted in some inconsistent findings. The aims of this meta-analysis were to (i) determine the pooled effect size for motivation to drink following priming, measured by alcohol consumption and craving, and (ii) examine whether design characteristics influenced any priming effect.

METHODS

Literature searches of PsycINFO, PubMed and Scopus in October 2020 (updated October 2021) identified lab-based alcohol priming studies that assessed effect of priming on motivation to drink. A tailored risk-of-bias tool assessed quality of lab-based studies. Random effects meta-analyses were computed on outcome data from 38 studies comparing the effect of a priming dose of alcohol against control on subsequent alcohol consumption/self-reported craving. Study characteristics that might have affected outcomes were design type (within/between-participant), dose of prime, time of motivation assessment, type of control drink (placebo alcohol/soft drink).

RESULTS

Relative to control, alcohol had a small-to-moderate priming effect on subsequent alcohol consumption (standardised mean difference [SMD] = 0.336 [95% CI, 0.171, 0.500]) and craving (SMD = 0.431 [95% CI, 0.306, 0.555]). Aspects of study design differentially affected consumption and craving. The size of the priming dose had no effect on consumption, but larger doses were sometimes associated with greater craving (with craving generally following the blood alcohol curve). Alcohol priming effects for consumption, but not craving, were smaller when compared with placebo, relative to soft drink, control.

CONCLUSIONS

Lab-based alcohol priming studies are a valid paradigm from which to investigate the impact of acute intoxication on alcohol motivation. Designs are needed that assess the impact of acute consumption on motivation to drink in more varied and realistic ways.

Central nervous system effects of TAK-653, an investigational alpha-amino-3-hydroxy-5-methyl-4-isoxazole receptor (AMPAR) positive allosteric modulator in healthy volunteers

TAK-653 is a novel AMPA receptor positive allosteric modulator in clinical development for the treatment of major depressive disorder (MDD). This study aimed to measure the functional pharmacodynamic central nervous system (CNS) effects of TAK-653. A randomised, double-blind, placebo-controlled, three-way crossover (placebo, TAK-653 0.5 mg and 6 mg) study with 24 healthy volunteers was performed. NeuroCart tests consisting of body sway (BS), saccadic peak velocity (SPV), smooth pursuit eye movements (SP), adaptive tracking (AT), Bowdle and Bond and Lader Visual Analogue Scales (B-VAS and BL-VAS) and Stroop test were performed pre-dose and 3.5 and 4 h post-dose. Data were analysed using a mixed model analysis of covariance with baseline as covariate. It was found that TAK-653 did not affect BS and subjective drug effects as measured by B-VAS and BL-VAS at either dose level. TAK-653 0.5 mg increased SPV (degrees/second) (19.49 [5.98, 32.99], P = 0.02) and affected Stroop difference in reaction time between correct congruent and correct incongruent answers and number of correct responses in incongruent trials (22.0 [4.0, 40.0], P = 0.05 and -0.3 [-0.5, -0.1], P = 0.02, respectively). TAK-653 6 mg improved AT (%) (1.68 [0.51, 2.84], P = 0.02) and increased SPV (degrees/s) (15.40 [1.91, 28.90], P = 0.06) and SP (%) (2.32 [0.37, 4.27], P = 0.05). Based on these findings it can be concluded that TAK-653 demonstrated a psychostimulant-like pharmacodynamic profile on the NeuroCart consistent with previously reported increase of cortical excitability following Transcranial Magnetic Stimulation (TMS) of the human motor cortex.

Neurobiological mechanisms of control in alcohol use disorder - moving towards mechanism-based non-invasive brain stimulation treatments

Alcohol use disorder (AUD) is characterized by excessive habitual drinking and loss of control over alcohol intake despite negative consequences. Both of these aspects foster uncontrolled drinking and high relapse rates in AUD patients. Yet, common interventions mostly focus on the phenomenological level, and prioritize the reduction of craving and withdrawal symptoms. Our review provides a mechanistic understanding of AUD and suggests alternative therapeutic approaches targeting the mechanisms underlying dysfunctional alcohol-related behaviours. Specifically, we explain how repeated drinking fosters the development of rigid drinking habits and is associated with diminished cognitive control. These behavioural and cognitive effects are then functionally related to the neurobiochemical effects of alcohol abuse. We further explain how alterations in fronto-striatal network activity may constitute the neurobiological correlates of these alcohol-related dysfunctions. Finally, we discuss limitations in current pharmacological AUD therapies and suggest non-invasive brain stimulation (like TMS and tDCS interventions) as a potential addition/alternative for modulating the activation of both cortical and subcortical areas to help re-establish the functional balance between controlled and automatic behaviour.

Acute alcohol does not impair attentional inhibition as measured with Stroop interference scores but impairs Stroop performance

RATIONALE

Inhibition is a core executive function and refers to the ability to deliberately suppress attention, behavior, thoughts, and/or emotions and instead act in a specific manner. While acute alcohol exposure has been shown to impair response inhibition in the stop-signal and Go/NoGo tasks, reported alcohol effects on attentional inhibition in the Stroop task are inconsistent. Notably, studies have operationalized attentional inhibition variably and there has been intra- and inter-individual variability in alcohol exposure.

OBJECTIVE

This study aimed to examine the acute effects of alcohol on attentional inhibition, considering previous limitations.

METHODS

In a single-blind, cross-over design, 40 non-dependent participants with a medium-to-high risk drinking behavior performed a Counting Stroop task (CST) under a baseline and an arterial blood alcohol concentration (aBAC) clamp at 80 mg%. Attentional inhibition was assessed as the alteration of reaction times (RT), error rates (ER), and inverse efficiency scores (IES) between incongruent and congruent trials (interference score). Stroop performance was also assessed regardless of trial-type.

RESULTS

Compared to saline, acute alcohol exposure via an aBAC clamp did not affect CST interference scores but increased RTs and IES in both incongruent and congruent trials.

CONCLUSIONS

Attentional inhibition (Stroop interference score) was not impaired by clamped moderate alcohol exposure. Acute alcohol impaired Stroop performance evidenced by a general increase in response times. Our findings suggest that response and attentional inhibition do not share the same neurocognitive mechanisms and are affected differently by alcohol. Results could also be explained by automated behaviors known to be relatively unaffected by acute alcohol.

Binge Drinking, Alone or With Cannabis, During Adolescence Triggers Different Effects on Immediate Visual Memory in Men and Women

Background: This study examines the interaction between a history of binge drinking (BD), alone or with cannabis consumption, and the effects of acute alcohol exposure on immediate visual memory (IVM) (faces memory task, scenes memory task and IVM-IQ) in adolescents of both sexes. Method: Two hundred and ninety adolescents, grouped into refrainers, binge drinkers and subjects with a history of simultaneous BD/Cannabis co-use, received a risk dose of alcohol or a control drink. Results: Consumption Pattern (refrainers vs. binge drinkers vs. BD/Cannabis consumers) was not significant, while Treatment (acute alcohol vs. control drink) was significant in both sexes. Also, male binge drinkers' performance in the faces memory task was poorer than that of refrainers and BD/Cannabis consumers who consumed the control drink. BD/Cannabis consumers performed this task as capably as refrainers. In women, binge drinkers performed better than refrainers in scene memory and IVM-IQ tests when given alcohol, and binge drinkers performed worse than refrainers after consuming the control drink. Conclusions: Acute alcohol consumption worsens IVM. Cannabis exerts a buffering effect in men. A cognitive tolerance effect is observed in women. Exposure during adolescence to alcohol, alone or with cannabis, can trigger different cognitive effects in men and women that could endure into adulthood.

Effect of alcohol on the sense of agency in healthy humans

Even at low to moderate doses, ingestion of the widely used recreational drug alcohol (ethanol) can impact cognitive and emotional processing. Recent studies show that the sense of agency (SoA; ie, the subjective experience of voluntary control over actions) can be modulated by specific pharmacological manipulations. The SoA, as quantified by the intentional binding (IB) paradigm, is enhanced by direct or indirect dopaminergic agonists in patients with Parkinson's disease and by ketamine (an N-methyl-D-aspartate (NMDA) receptor antagonist) in healthy individuals. These findings implicate dopaminergic and glutamatergic neurotransmission in mechanisms underlying SoA. Alcohol has a complex set of actions, including disinhibition of dopaminergic neurotransmission and allosteric antagonism at NMDA receptors. Here, we tested the hypothesis that low to moderate doses of alcohol would enhance SoA, and impact impulsivity and subjective emotional state. We conducted two experiments in 59 healthy male and female social drinkers, who ingested either a placebo "vehicle," or one of two doses of ethanol: 0.4 and 0.6 g/kg. In both experiments, we observed increased SoA/IB at both doses of alcohol exposure, relative to the placebo condition. We found no correlation between the effects of alcohol on IB and on impulsivity or subjective emotional state. Our findings might have implications for social and legal responsibility related to alcohol use, particularly in states prior to overt intoxication. Further studies are necessary to investigate the effects of alcohol and other addictive substances on the SoA.

"Free won't" after a beer or two: chronic and acute effects of alcohol on neural and behavioral indices of intentional inhibition

BACKGROUND

Response inhibition can be classified into stimulus-driven inhibition and intentional inhibition based on the degree of endogenous volition involved. In the past decades, abundant research efforts to study the effects of alcohol on inhibition have focused exclusively on stimulus-driven inhibition. The novel Chasing Memo task measures stimulus-driven and intentional inhibition within the same paradigm. Combined with the stop-signal task, we investigated how alcohol use affects behavioral and psychophysiological correlates of intentional inhibition, as well as stimulus-driven inhibition.

METHODS

Experiment I focused on intentional inhibition and stimulus-driven inhibition in relation to past-year alcohol use. The Chasing Memo task, the stop-signal task, and questionnaires related to substance use and impulsivity were administered to 60 undergraduate students (18-25 years old). Experiment II focused on behavioral and neural correlates acute alcohol use on performance on the Chasing Memo task by means of electroencephalography (EEG). Sixteen young male adults (21-28 years old) performed the Chasing Memo task once under placebo and once under the influence of alcohol (blood alcohol concentration around 0.05%), while EEG was recorded.

RESULTS

In experiment I, AUDIT (Alcohol Use Disorder Identification Test) total score did not significantly predict stimulus-driven inhibition or intentional inhibition performance. In experiment II, the placebo condition and the alcohol condition were comparable in terms of behavioral indices of stimulus-driven inhibition and intentional inhibition as well as task-related EEG patterns. Interestingly, a slow negative readiness potential (RP) was observed with an onset of about 1.2 s, exclusively before participants stopped intentionally.

CONCLUSIONS

These findings suggest that both past-year increases in risky alcohol consumption and moderate acute alcohol use have limited effects on stimulus-driven inhibition and intentional inhibition. These conclusions cannot be generalized to alcohol use disorder and high intoxication levels. The RP might reflect processes involved in the formation of an intention in general.

Acute alcohol exposure dose-dependently alleviates social avoidance in adolescent mice and inhibits social investigation in adult mice

BACKGROUND

Motivations for alcohol consumption often focus on ethanol's purported prosocial effects: social enhancement and reduction of socially focused anxiety. Despite substantial research supporting prosocial effects, contrary research exists demonstrating alcohol-elicited antisocial and asocial behaviours. Additionally, evidence typically fails to delineate whether alcohol-induced prosocial effects are due to alcohol expectancies or pharmacological actions of ethanol. Studies exploring ethanol's pharmacological effects on social behaviour and factors that modulate apparent contradictory prosocial versus asocial effects are lacking.

OBJECTIVES

This study investigated whether factors of age, ethanol dose and social fear modulate ethanol-induced pharmacological effects on sociability and social anxiety-like avoidance.

METHODS

Experiments examined the acute effects of ethanol doses (0, 0.25, 0.8, 1.6 g/kg; i.p.) in adult (10-week-old) and adolescent (PND 31-33) C57BL/6J male mice on social interaction using a social fear conditioning paradigm. Control experiments assessed whether ethanol-induced effects were social-specific.

RESULTS

In adult mice, no specific effects of ethanol on social avoidance were observed at any dose. However, high-dose ethanol (1.6 g/kg) suppressed social approach in all adult mice. In contrast, low-dose ethanol (0.25 g/kg) alleviated social avoidance in adolescent mice and no social suppression was observed at higher ethanol doses. Thus, higher doses of ethanol impair social behaviour in adult mice, whereas lower doses specifically alleviate social anxiety-like avoidance in adolescent mice.

CONCLUSIONS

Age, dose and social fear are critical modulators of acute ethanol-induced pharmacological effects on social behaviour. Inconsistencies in ethanol-induced social consequences appear at least partly mediated by pharmacological interactions-not solely alcohol expectancies.

Effects of Acute Alcohol Consumption on the Human Brain: Diffusional Kurtosis Imaging and Arterial Spin-Labeling Study

BACKGROUND AND PURPOSE

Brain function and microstructure are affected by alcohol consumption. Until recently, the effect of alcohol on neural mechanisms has not been fully elucidated. Our aim was to explore the acute effects of alcohol on healthy human brains by diffusional kurtosis imaging and 3D arterial spin-labeling and elucidate structural and functional changes in the brain on acute alcohol intake.

MATERIALS AND METHODS

Conventional MR imaging, diffusional kurtosis imaging, and 3D arterial spin-labeling were performed on 24 healthy volunteers before and 0.5 and 1 hour after drinking alcohol. Participants were divided into 2 groups according to the response to alcohol: blushing (n = 12) and unblushing (n = 12) groups. Twenty brain regions were analyzed.

RESULTS

Diffusional kurtosis imaging revealed an increase in mean kurtosis and fractional anisotropy at 0.5 hour post-alcohol intake in most brain regions, whereas mean diffusion was decreased in several brain regions at 1 hour after drinking. 3D arterial spin-labeling showed increased cerebral blood flow in most brain regions, particularly in the frontal regions. However, perfusion in the anterior commissure decreased. Regional changes in the brain correlated with various behavioral performances with respect to blush response and sex. In general, blushing individuals and men are more sensitive to alcohol with acute effects.

CONCLUSIONS

Physiologic and microstructural alterations in the brain on alcohol consumption were examined. Brain areas with blood flow alteration detected by 3D arterial spin-labeling were highly consistent with susceptible areas detected by diffusional kurtosis imaging. The current study provides new insight into the effects of alcohol on the brain and behavioral performance in different blush response and sex populations.

Does Self-Reported or Behavioral Impulsivity Predict Subjective Response to Low-Dose Alcohol?

AIMS

Subjective response to alcohol and impulsivity are both independent predictors of alcohol use and may be related risk factors for alcohol use disorders (AUDs). Recent findings suggest that more impulsive individuals may experience higher risk subjective response patterns at moderate-to-high doses of alcohol. However, whether these relationships are observable early in a drinking occasion remains an open question. This study examined multiple measures of impulsivity in relation to subjective response following low-dose alcohol.

METHOD

Eighty-seven non-treatment-seeking heavy drinkers were enrolled in a placebo-controlled alcohol administration study testing the effects of NMDA receptor antagonist, Memantine. Baseline impulsivity assessments included the Cued Go/No-Go Task, Experiential Discounting Task, and Barratt Impulsiveness Scale, Version 11 (BIS-11). Following consumption of low-dose alcohol aimed to increase blood alcohol concentration (BAC) to 0.03%, subjective stimulation and sedation were measured using the Biphasic Alcohol Effects Scale. Models were tested to relate impulsivity measures to subjective response with a post hoc exploratory model exploring boredom as an alternate predictor.

RESULTS

Increases in stimulation and sedation were observed following low-dose alcohol, but were not predicted significantly by impulsivity measures. Although greater impulsivity on the BIS-11 was a trend-level predictor of increased sedation, post hoc analyses suggested these results were an artifact of boredom.

CONCLUSION

Although impulsivity did not predict subjective response to low-dose alcohol, the results suggest that small amounts of alcohol can produce a range of subjective effects, even among heavy drinkers. Future studies would benefit by examining subjective response across a range of BACs among both light and heavy drinkers.

On the Neurobiological Role of Oxidative Stress in Alcohol-Induced Impulsive, Aggressive and Suicidal Behavior

Objectives: Alcohol abuse is known to result in behavioral impairments (such as increased impulsivity, aggressive, and suicidal behavior), but the neurobiological basis for these behavioral impairments remains unknown. The objective of this review is to propose a neurobiological basis for alcohol-induced aggression, impulsivity, and suicidal behavior. Methods: Search was done by accessing PubMed/Medline, EBSCO, and PsycINFO databases. The search string used was "(Alcohol OR Alcoholism* OR Alcohol Abuse) AND (Behavior* OR Behavioral Impairment or Disorder) AND (Oxidative Stress OR Reactive Oxygen Species)." The electronic databases were searched for titles or abstracts containing these terms in all published articles between January 1, 1960, and May 31, 2019. The search was limited to studies published in English and other languages involving both animal and human subjects. Articles selected included randomized clinical trials (RCTs), observational studies, meta-analyses, and both systemic and narrative reviews, providing both quantitative and qualitative information with a measure of alcohol abuse or alcoholism as an outcome. Exclusion criteria were unpublished data of any form, including conference proceedings and dissertation. New key terms were identified (new term included: "Antioxidants, Neurotransmitters, Dopamine, Serotonin, GABA, Glutamate. Aggression, Impulsivity, Suicidal Behavior, hippocampus, prefrontal cortex, limbic system, psychiatric disorders, PTSD, Anxiety, Depression. These new terms were searched with Alcohol or Alcoholism or Alcohol Abuse and Oxidative Stress separately resulting in the identification of over 3000 articles. 196 were included in this article. Results: Multiple lines of evidence indicate that oxidative stress (OS) plays a critical underlying role in alcohol toxicity and behavioral impairments. Conclusions/Importance: People diagnosed with PTSD, anxiety disorder, depression, and those with a personality high in psychoticism as measured by the P Scale of the Eysenck Personality Questionnaire, with comorbid alcohol abuse or alcohol use disorder (AUD), may display increased impulsivity, aggression, and suicidal behavior because of the potentiating effect of alcohol-induced OS on their elevated brain oxidative status. Antioxidant therapy should be an integral part of acute alcohol intoxication and AUD treatment. Further research is necessary to fully understand the relationship between OS and alcohol-induced behavioral impairments.

The effect of alcohol cue exposure and acute intoxication on inhibitory control processes and ad libitum alcohol consumption

RATIONALE

Alcohol intoxication and alcohol cue exposure impair 'reactive' inhibitory control and increase motivation to drink. However, inhibitory control is a multi-component process that also comprises signal detection and proactive control. It is unknown whether intoxication and cue exposure selectively influence these subprocesses in heavy drinkers.

OBJECTIVES

In two pre-registered studies, we investigated whether exposure to alcohol-related cues (study 1) and alcohol priming (study 2) impair each of these subprocesses of inhibitory control and increase motivation to drink.

METHODS

In study 1, 64 heavy drinkers completed a modified stop-signal task in an alcohol context (with embedded alcohol cues) and a neutral context (with embedded neutral cues) followed by a subjective measure of craving and a bogus taste test to measure ad libitum alcohol consumption. In study 2, 36 heavy drinkers consumed an alcoholic beverage (0.6 g/kg body weight), an alcohol-placebo beverage, and water on a within-subjects basis, followed by the modified stop-signal task and a bogus taste test.

RESULTS

In study 1, alcohol cue exposure did not impair inhibitory control subprocesses. Reactive control was unexpectedly better following alcohol cue exposure (compared to neutral cue exposure). However, craving and ad libitum consumption increased as expected. In study 2, reactive control was significantly impaired following the alcohol and control primes, relative to the placebo, but there was no effect on proactive slowing or signal detection. As expected, intoxication increased motivation to drink and ad libitum consumption (compared to placebo and control).

CONCLUSIONS

Alcohol intoxication and cue exposure increase motivation to drink in the absence of impairments in subcomponents of inhibitory control.

The effect of beliefs about alcohol's acute effects on alcohol priming and alcohol-induced impairments of inhibitory control

Acute alcohol administration can lead to a loss of control over drinking. Several models argue that this 'alcohol priming effect' is mediated by the effect of alcohol on inhibitory control. Alternatively, beliefs about how alcohol affects behavioural regulation may also underlie alcohol priming and alcohol-induced inhibitory impairments. Here two studies examine the extent to which the alcohol priming effect and inhibitory impairments are moderated by beliefs regarding the effects of alcohol on the ability to control behaviour. In study 1, following a priming drink (placebo or .5g/kg of alcohol), participants were provided with bogus feedback regarding their performance on a measure of inhibitory control (stop-signal task; SST) suggesting that they had high or average self-control. However, the bogus feedback manipulation was not successful. In study 2, before a SST, participants were exposed to a neutral or experimental message suggesting acute doses of alcohol reduce the urge to drink and consumed a priming drink and this manipulation was successful. In both studies craving was assessed throughout and a bogus taste test which measured ad libitum drinking was completed. Results suggest no effect of beliefs on craving or ad lib consumption within either study. However, within study 2, participants exposed to the experimental message displayed evidence of alcohol-induced impairments of inhibitory control, while those exposed to the neutral message did not. These findings do not suggest beliefs about the effects of alcohol moderate the alcohol priming effect but do suggest beliefs may, in part, underlie the effect of alcohol on inhibitory control.

Alcohol effects on response inhibition: Variability across tasks and individuals

Considerable research has investigated the acute effects of alcohol on response inhibition, but a number of issues remain unresolved. Given that most studies use only a single laboratory task to assess inhibition, it is often difficult to determine whether alcohol's effects are task specific or generalize across measures of the same construct. Moreover, relatively few studies have directly compared effects of alcohol under ascending and descending blood alcohol concentrations (BACs), and those that have often failed to disentangle BAC limb effects from the effects of repeated testing. This study was intended to provide a test of alcohol's effects on behavioral inhibition using multiple laboratory measures in a relatively large sample and comparing effects under ascending and descending BAC. Young adults (N = 216) completed three commonly used inhibition tasks (Stroop, antisaccade, and stop-signal) at baseline and again 1-3 weeks later under one of three beverage conditions (alcohol, placebo or control) and one of two BAC limb conditions (ascending/descending or descending only). Findings indicated considerable specificity in alcohol's effects. Relative to control and placebo conditions, antisaccade performance suffered under both ascending and descending BAC and stop-signal reaction time (RT) suffered only under descending BAC. The Stroop RT interference effect was not affected by alcohol, though alcohol did impair response accuracy on incongruent Stroop trials. Baseline performance moderated effects of alcohol on both antisaccade accuracy and Stroop interference, suggesting the importance of individual differences. The current findings suggest that more specificity is required in characterizing acute effects of alcohol on inhibitory control. (PsycINFO Database Record

Acute alcohol effects on facial expressions of emotions in social drinkers: a systematic review

Background

As known from everyday experience and experimental research, alcohol modulates emotions. Particularly regarding social interaction, the effects of alcohol on the facial expression of emotion might be of relevance. However, these effects have not been systematically studied. We performed a systematic review on acute alcohol effects on social drinkers' facial expressions of induced positive and negative emotions.

Materials and methods

With a predefined algorithm, we searched three electronic databases (PubMed, PsycInfo, and Web of Science) for studies conducted on social drinkers that used acute alcohol administration, emotion induction, and standardized methods to record facial expressions. We excluded those studies that failed common quality standards, and finally selected 13 investigations for this review.

Results

Overall, alcohol exerted effects on facial expressions of emotions in social drinkers. These effects were not generally disinhibiting, but varied depending on the valence of emotion and on social interaction. Being consumed within social groups, alcohol mostly influenced facial expressions of emotions in a socially desirable way, thus underscoring the view of alcohol as social lubricant. However, methodical differences regarding alcohol administration between the studies complicated comparability.

Conclusion

Our review highlighted the relevance of emotional valence and social-context factors for acute alcohol effects on social drinkers' facial expressions of emotions. Future research should investigate how these alcohol effects influence the development of problematic drinking behavior in social drinkers.

Impairment of manual but not saccadic response inhibition following acute alcohol intoxication

BACKGROUND

Alcohol impairs response inhibition; however, it remains contested whether such impairments affect a general inhibition system, or whether affected inhibition systems are embedded in, and specific to, each response modality. Further, alcohol-induced impairments have not been disambiguated between proactive and reactive inhibition mechanisms, and nor have the contributions of action-updating impairments to behavioural 'inhibition' deficits been investigated.

METHODS

Forty Participants (25 female) completed both a manual and a saccadic stop-signal reaction time (SSRT) task before and after a 0.8g/kg dose of alcohol and, on a separate day, before and after a placebo. Blocks in which participants were required to ignore the signal to stop or make an additional 'dual' response were included to obtain measures of proactive inhibition as well as updating of attention and action.

RESULTS

Alcohol increased manual but not saccadic SSRT. Proactive inhibition was weakly reduced by alcohol, but increases in the reaction times used to baseline this contrast prevent clear conclusions regarding response caution. Finally, alcohol also increased secondary dual response times of the dual task uniformly as a function of the delay between tasks, indicating an effect of alcohol on action-updating or execution.

CONCLUSIONS

The modality-specific effects of alcohol favour the theory that response inhibition systems are embedded within response modalities, rather than there existing a general inhibition system. Concerning alcohol, saccadic control appears relatively more immune to disruption than manual control, even though alcohol affects saccadic latency and velocity. Within the manual domain, alcohol affects multiple types of action updating, not just inhibition.

Blood Alcohol Concentration-Related Lower Performance in Immediate Visual Memory and Working Memory in Adolescent Binge Drinkers

The binge drinking (BD) pattern of alcohol consumption is prevalent during adolescence, a period characterized by critical changes to the structural and functional development of brain areas related with memory and cognition. There is considerable evidence of the cognitive dysfunctions caused by the neurotoxic effects of BD in the not-yet-adult brain. Thus, the aim of the present study was to evaluate the effects of different blood alcohol concentrations (BAC) on memory during late adolescence (18–19 years old) in males and females with a history of BD. The sample consisted of 154 adolescents (67 males and 87 females) that were classified as refrainers if they had never previously drunk alcoholic drinks and as binge drinkers if they had drunk six or more standard drink units in a row for men or five or more for women at a minimum frequency of three occasions in a month, throughout the previous 12 months. After intake of a high acute dose of alcohol by binge drinkers or a control refreshment by refrainers and binge drinkers, subjects were distributed into four groups for each gender according to their BAC: BAC0-R (0 g/L, in refrainers), BAC0-BD (0 g/L, in binge drinkers), BAC1 (0.3 – 0.5 g/L, in binge drinkers) or BAC2 (0.54 – 1.1 g/L, in binge drinkers). The subjects’ immediate visual memory and working memory were then measured according to the Wechsler Memory Scale (WMS-III). The BAC1 group showed lower scores of immediate visual memory but not of working memory, while lower performance in both memories were found in the BAC2 group. Therefore, the brain of binge drinkers with moderate BAC could be employing compensatory mechanisms from additional brain areas to perform a working memory task adequately, but these resources would be undermined when BAC is higher (>0.5 g/L). No gender differences were found in BAC-related lower performance in immediate visual memory and working memory. In conclusion, immediate visual memory is more sensitive than working memory to the neurotoxic effects of alcohol in adolescent binge drinkers of both genders, being a BAC-related lower performance, and without obvious differences between males and females.

Resisting the urge to smoke: inhibitory control training in cigarette smokers

Impaired response inhibition is an important factor in tobacco dependence. We examined the effects of inhibitory control training (ICT) on inhibition, smoking resistance and cigarette use. Smokers (n = 55) abstained from smoking for 12 h prior to testing. On the test day, participants recorded cigarette use and completed pre-training measures of global and cue-specific (smoking-related) response inhibition. Participants were randomized to either an active or a control ICT group. The active group was required to repeatedly inhibit a response towards smoking cues (100%), while the control group was required to inhibit a response towards smoking and neutral cues with equal frequency (50%). Participants performed post-training measures of response inhibition, smoking resistance and cigarette use. Inhibition data did not indicate time (pre-training, post-training) × group (active training, control training) or time × group × cue (smoking, neutral) interactions. There was weak evidence that smokers in the active group were more likely to resist smoking than those in the control group. Cigarette use data did not indicate a time × group interaction. Our data suggest that ICT may enhance the ability to resist smoking, indicating that training may be a promising adjunct to smoking pharmacotherapy.

Binge drinking affects brain oscillations linked to motor inhibition and execution

INTRODUCTION

Neurofunctional studies have shown that binge drinking patterns of alcohol consumption during adolescence and youth are associated with anomalies in brain functioning. Recent evidence suggests that event-related oscillations may be an appropriate index of neurofunctional damage associated with alcoholism. However, there is no study to date that has evaluated the effects of binge drinking on oscillatory brain responses related to task performance. The purpose of the present study was to examine brain oscillations linked to motor inhibition and execution in young binge drinkers (BDs) compared with age-matched controls.

METHODS

Electroencephalographic activity was recorded from 64 electrodes while 72 university students (36 controls and 36 BDs) performed a visual Go/NoGo task. Event-related oscillations along with the Go-P3 and NoGo-P3 event-related potential components were analysed.

RESULTS

While no significant differences between groups were observed regarding event-related potentials, event-related oscillation analysis showed that BDs displayed a lower oscillatory response than controls in delta and theta frequency ranges during Go and NoGo conditions.

CONCLUSIONS

Findings are congruent with event-related oscillation studies showing reduced delta and/or theta oscillations in alcoholics during Go/NoGo tasks. Thus, BDs appear to show disruptions in neural oscillations linked to motor inhibition and execution similar to those observed in alcohol-dependent subjects. Finally, these results are the first to evidence that oscillatory brain activity may be a sensitive indicator of underlying brain anomalies in young BDs, which could complement standard event-related potential measures.

Alcohol drinking patterns in young people: A survey-based study

Binge drinking represents a major clinical and public health concern. Here, we investigated the prevalence of binge drinking and its related consequences, in a population of young adults. A questionnaire was administered to a sample of 4275 healthy subjects. In the overall sample, the percentage of binge drinkers was 67.6 per cent; among regular alcohol users, 79.5 per cent reported episodes of binge drinking. Among binge drinkers, several serious consequences were identified (staggering and stuttering, amnesia, loss of control, aggressiveness, sexual disinhibition). Raising awareness about the seriousness of binge drinking may help health care providers to identify cases early on and provide appropriate treatments.

The Association of Alcohol Use Disorders with Suicidal Ideation and Suicide Attempts in a Population-Based Sample with Mood Symptoms

Using population-based data, we examined associations between alcohol use disorders (AUD) and suicidality, assessing effect modification by mood disorders, and mediation by drinking level. Suicidality was assessed among current drinkers with 2-weeks of low mood (n = 9,173) in the National Epidemiologic Survey on Alcohol and Related Conditions. Independent of mood disorder, alcohol dependence, was associated with suicidal ideation (adjusted odds ratio [AOR] = 1.64; 95% confidence interval [CI] = 1.25-2.14), and suicide attempts (AOR = 2.02; CI = 1.43-2.85) relative to those without AUD. Findings indicate partial mediation by consumption. Associations between AUD and suicidality among those with low mood are not explained by comorbid mood disorder, but are partially mediated by drinking level. Future studies should evaluate transitions in suicidality with change in consumption.

Disinhibition of olfaction: human olfactory performance improves following low levels of alcohol

We hypothesize that true human olfactory abilities are obscured by cortical inhibition. Alcohol reduces inhibition. We therefore tested the hypothesis that olfactory abilities will improve following alcohol consumption. We measured olfaction in 85 subjects, 45 in a between-subjects design, and 40 in a repeated-measures within-subjects design before and after consumption of alcoholic or non-alcoholic beverages. Subjects were also assessed using neurocognitive measures of inhibition. Following alcohol consumption, blood alcohol levels ranged from 0.005% to 0.11%. Across subjects, before any consumption of alcohol, we found that individuals who were less inhibited had lower (better) olfactory detection thresholds (r=0.68, p<0.005). Moreover, after alcohol consumption, subjects with low alcohol levels could make olfactory discriminations that subjects with 0% alcohol could not make (chance=33%, alcohol=51.3±22.7%, control=34.7±31.6%, t(43)=2.03, p<0.05). Within subjects, we found correlations between levels of alcohol and olfactory detection (r=0.63, p<0.005) and discrimination (r=-0.50, p<0.05), such that performance was improved at low levels of alcohol (significantly better than baseline for detection) and deteriorated at higher levels of alcohol. Finally, levels of alcohol-induced improved olfactory discrimination were correlated with levels of alcohol-induced cognitive disinhibition (r=0.48, p<0.05). Although we cannot rule out alternative non-inhibitory alcohol-induced routes of influence, we conclude that improved olfaction at low levels of alcohol supports the notion of an inhibitory mechanism obscuring true olfactory abilities.

Alcohol: Pharmacology and Disposition

Alcohol is the most common drug detected in forensic cases, is often associated with increased aggression and other disinhibitory behaviors in criminal matters, and frequently contributes to the cause of death in medical examiner cases. Significant adverse effects of alcohol generally manifest at blood alcohol concentrations above 100 mg/dL. In postmortem cases, a number of factors can affect the accuracy of the blood measurement, including site of sampling and putrefactive formation. This paper provides an overview of the pharmacology, pharmacokinetics, and interpretation of alcohol and its concentrations in key specimens, with application to forensic medical cases.

Alcohol disinhibition of behaviors in C. elegans

Alcohol has a wide variety of effects on physiology and behavior. One of the most well-recognized behavioral effects is disinhibition, where behaviors that are normally suppressed are displayed following intoxication. A large body of evidence has shown that alcohol-induced disinhibition in humans affects attention, verbal, sexual, and locomotor behaviors. Similar behavioral disinhibition is also seen in many animal models of ethanol response, from invertebrates to mammals and primates. Here we describe several examples of disinhibition in the nematode C. elegans. The nematode displays distinct behavioral states associated with locomotion (crawling on land and swimming in water) that are mediated by dopamine. On land, animals crawl and feed freely, but these behaviors are inhibited in water. We found that additional behaviors, including a variety of escape responses are also inhibited in water. Whereas alcohol non-specifically impaired locomotion, feeding, and escape responses in worms on land, alcohol specifically disinhibited these behaviors in worms immersed in water. Loss of dopamine signaling relieved disinhibition of feeding behavior, while loss of the D1-like dopamine receptor DOP-4 impaired the ethanol-induced disinhibition of crawling. The powerful genetics and simple nervous system of C. elegans may help uncover conserved molecular mechanisms that underlie alcohol-induced disinhibition of behaviors in higher animals.

Effects of alcohol on attentional mechanisms involved in figure reversals

OBJECTIVE

The impairing effects of alcohol on attention are well documented and are thought to involve inhibitory mechanisms. We used ambiguous figures (Face-Vase and Necker cube) to test whether the intentional control mechanism is more vulnerable to the effects of alcohol than the automatic mechanism.

METHOD

Participants were assigned to an alcohol (Study 1, N = 15; Study 2, N = 18), placebo (Study 1, N = 15; Study 2, N = 20) or control (Study 1 only, N = 10) group. The doses of alcohol were 0.8 g/kg for men and 0.75 g/kg for women. Participants were shown the Face-Vase and Necker cube figures and two variants of each, which were biased in varying degrees towards one interpretation. Study 1 assessed the automatic control mechanism by asking participants to report spontaneous reversals. Study 2 assessed the intentional control mechanism by asking participants to increase reversal rate.

RESULTS

In Study 1, reversal rate was similar for all groups, whereas in Study 2, the alcohol group reported more reversals than the control group, although this was true only for the biased versions of the Face-Vase illusion.

CONCLUSIONS

The effect of alcohol on reversal rate is observed only during intentional reversals of semantically meaningful stimuli and only when the stimulus is biased.

Acute alcohol effects on subtypes of impulsivity and the role of alcohol-outcome expectancies

RATIONALE

It is well established that alcohol acutely impairs the ability to inhibit a pre-potent response (motor impulsivity), but its effects on cognitive impulsivity, including temporal (delayed gratification) and reflection (decision making) impulsivity, are not clear. An important factor contributing to the effects of alcohol is cognitive expectancies of alcohol-related outcomes.

OBJECTIVES

The current study investigated the effect of alcohol, and alcohol outcome expectancies, on subtypes of impulsivity.

METHODS

Impulsivity was tested using the Stop Signal, the Single Key Impulsivity and the Information Sampling Task for motor, temporal and reflection impulsivity, respectively. Participants (n = 48) received placebo, a low (0.4 g/kg) or high dose (0.8 g/kg) of alcohol, before completing the impulsivity measures.

RESULTS

Motor impulsivity was affected by alcohol dose; participants receiving a high dose displayed reduced inhibitory control. Reflection impulsivity was affected by cognitive alcohol expectancies, but not by alcohol condition; participants expecting greater cognitive and behavioural impairment by alcohol exhibited low impulsivity. Temporal impulsivity was not affected by either alcohol dose or outcome expectancies.

CONCLUSIONS

These data suggest that the effects of alcohol on the subtypes of impulsivity are dissociable. Motor impulsivity is sensitive to the pharmacological effects of alcohol, whereas the reflection subtype is affected by cognitive alcohol expectancies. The findings have implications for the understanding of impulsive behaviour under the influence of alcohol.

A comparison of the anticipated and pharmacological effects of alcohol on cognitive bias, executive function, craving and ad-lib drinking

Acute alcohol administration alters automatic processing of alcohol-related cues, impairs executive functions and increases alcohol seeking. Few studies have investigated the effects of expecting to receive alcohol on these measures. Thirty-one social drinkers completed three experimental sessions receiving either 0.65 g/kg alcohol, a placebo and a control beverage (which they knew was not alcoholic) before reporting craving and completing a test battery including a measure of automatic alcohol-approach tendencies (stimulus response compatibility task), a measure of executive function (Controlled Oral Word Association Task (COWAT)) and a taste test assessing ad-lib drinking. Results indicated that alcohol administration impaired performance on the COWAT and increased ad-lib drinking; however, there were no significant differences on these measures after administration of placebo versus control beverages. Craving was increased after alcohol and (to a lesser extent) after placebo. Automatic alcohol-approach tendencies were pronounced after both alcohol and placebo compared to the control beverage, with no difference between alcohol and placebo. Results suggest craving is sensitive to the anticipated and pharmacological effects of alcohol, alcohol-approach tendencies are particularly sensitive to the anticipated effects of alcohol, and measures of executive function and ad-lib drinking are affected by the pharmacological, but not the anticipated, effects of alcohol.

Effects of caffeine on alcohol-related changes in behavioural control and perceived intoxication in light caffeine consumers

RATIONALE

Caffeinated alcoholic beverages have been associated with increased risk of alcohol-related harms. However, few studies have examined these combined effects on behavioural control, which is believed to underlie many of the negative effects of alcohol consumption. In addition, studies have often omitted subjective measures, and none have directly assessed the role of caffeine consumer history.

OBJECTIVES

To examine the combined effects of alcohol and caffeine on measures of behavioural control and perceived intoxication in abstinent, light caffeine consumers.

METHODS

Participants (n = 28; 50% male) attended four sessions at which they consumed one of the following beverages in a randomised order: placebo, alcohol alone (0.6 g/kg), caffeine alone (2.0 mg/kg), and alcohol/caffeine. They completed measures of mood, intoxication, anxiety and alcohol craving before and after a task battery comprising measures of behavioural control and reaction time performance.

RESULTS

Caffeine attenuated alcohol-related performance deficits on stop-signal accuracy, had no effect on go-no-go performance deficits, and worsened accuracy on the Stroop task. Caffeine did not influence absolute changes in perceived intoxication but there was suggestion that caffeine may have changed the nature of intoxication with increases in stimulation.

CONCLUSIONS

Caffeine appears to have mixed effects on alcohol intoxication that are task-dependent. We found increased stimulation in the alcohol/caffeine condition, supporting the contention that caffeinated alcoholic beverages enable an individual to drink for longer. Future research should model real world drinking behaviour by examining how these effects change across multiple drink administrations.

Ethanol reduces the phase locking of neural activity in human and rodent brain

How the neuromolecular actions of ethanol translate to its observed intoxicating effects remains poorly understood. Synchrony of phase (phase locking) of event-related oscillations (EROs) within and between different brain areas has been suggested to reflect communication exchange between neural networks and as such may be a sensitive and translational measure of ethanol's effects. Using a similar auditory event-related potential paradigm in both rats and humans we investigated the phase variability of EROs collected from 38 young men who had participated in an ethanol/placebo challenge protocol, and 46 adult male rats given intraperitoneal injections of ethanol/saline. Phase locking was significantly higher in the delta frequencies in humans than in rats. Phase locking was also higher for the rare (target) tone than the frequent (non-target) tone in both species. Significant reductions in phase locking to the rare (target) tone in the delta, theta, alpha, beta and gamma frequencies, within and between brain sites, was found at 1h following ethanol as compared to placebo/saline administration in both rats and humans. Reductions in phase locking in the alpha frequencies in the parietal cortex were found to be correlated with blood ethanol concentrations. These findings are consistent with the hypothesis that ethanol's intoxicating actions in the brain include reducing synchrony within and between neuronal networks, perhaps by increasing the level of noise in key neuromolecular interactions.

Alcohol selectively impairs negative self-relevant associations in young drinkers

The stress-dampening effects of alcohol have been attributed to 'appraisal disruption'- decreased ability of stimuli to evoke threatening associations in memory. Appraisal disruption could apply to oneself as well as situational stimuli. This question was investigated in undergraduate drinkers (n=90/Gender) with low or high anxiety sensitivity (AS; n=90/AS Group), a trait linked with hyper-vigilance to threat. Subjects received alcohol (0.7 g/kg males; 0.63 g/kg females), placebo or soft drink and performed a speech about their appearance. Sequence of drink administration and speech advisory (threat) was manipulated between subjects: Threat before Drink, Threat after Drink, No-Threat Control. The Implicit Association Test measured self-relevant associations based upon time to classify positive and negative attribute words (e.g. Cute, Ugly) paired with self-relevant or non-self-relevant object words (e.g. Me, Them). Alcohol selectively slowed negative self-relevant decisions, regardless of other factors. Relative fluency of negative versus positive decisions (D) correlated inversely with state anxiety and systolic blood pressure immediately before speech performance, and correlated directly with severity of alcohol problems. These findings are consistent with the Appraisal Disruption hypothesis. Preferential impairment of negative self-relevant associations may decrease perceived vulnerability under alcohol and increase risk for alcohol problems in young drinkers.

Alcohol affects the emotional modulation of cognitive control: an event-related brain potential study

OBJECTIVE

The present study aimed to determine whether alcohol affects the emotional modulation of cognitive control and its underlying neural mechanisms, which is pivotal to an understanding of the socially maladaptive behaviors frequently seen in alcohol-intoxicated individuals.

METHOD

Event-related potentials (ERPs) were recorded in male participants receiving either a moderate dose of alcohol (0.65 g/kg alcohol; n = 32) or a non-alcoholic placebo beverage (n = 32) while performing an emotional Go/No-Go task that required response execution (Go trials) to pictures of a "target" emotional facial expression (angry, happy, neutral) and response inhibition (No-Go trials) to a different "non-target" expression.

RESULTS

Overall, N200 and P300 amplitudes were more enhanced during No-Go than Go trials. Interestingly, alcohol-intoxicated individuals displayed larger No-Go N200 amplitudes across all emotional conditions than controls, accompanied by decreased task performance (i.e., more errors), particularly in response to angry faces. P300 amplitude in the alcohol group was significantly reduced for both Go and No-Go trials, but only following angry and happy emotional expressions.

CONCLUSIONS

These results suggest that alcohol-intoxicated individuals need to effortfully activate more cognitive resources during the early inhibition process in order to regulate a response than controls. Moreover, alcohol affected the emotional modulation of both response inhibition and execution in the later stages of cognitive control. Alcohol dampened emotional responsiveness, which may restrict the availability of attentional resources for cognitive control. Yet, these findings may underlie the lack of control in alcohol-intoxicated individuals when faced with emotionally or socially challenging situations.

Conditioned tolerance to the effects of alcohol on inhibitory control in humans

AIMS

To test whether the repeated consumption of alcohol in a particular environment leads to the emergence of a context-specific conditioned compensatory response (CCR) that can counter alcohol's impairment of inhibitory processes.

METHODS

Twenty-four participants consumed an alcoholic drink (males: 0.65 g/kg; females: 0.57 g/kg) in one context on three sessions and a matched placebo drink in a different context on three other sessions. At test, participants were split into two groups and consumed a novel alcoholic drink either in the context previously paired with alcohol or the placebo-paired context. On all sessions, participants were tested on two computer-based tasks that measured response inhibition: an affective go/no-go task and a stop-signal task (SST).

RESULTS

Over the conditioning trials, tolerance developed to alcohol's disinhibitory effects on the go/no-go task; moreover, on the test for conditioned responding, performance was less impaired for participants in the alcohol-paired versus the placebo-paired context. No tolerance was evident on the SST, and no CCR.

CONCLUSION

Repeated consumption of alcohol in a particular environment can lead to the emergence of a context-specific CCR that counters some of alcohol's disinhibitory effects. Therefore, consuming alcohol in an unfamiliar context might produce stronger disinhibitory effects than would be apparent in a familiar drinking environment.

Pseudocontinuous arterial spin labeling reveals dissociable effects of morphine and alcohol on regional cerebral blood flow

We have examined sensitivity and specificity of pseudocontinuous arterial spin labeling (PCASL) to detect global and regional changes in cerebral blood flow (CBF) in response to two different psychoactive drugs. We tested alcohol and morphine in a placebo-controlled, double-blind randomized study in 12 healthy young men. Drugs were administered intravenously. Validated pharmacokinetic protocols achieved minimal intersubject and intrasubject variance in plasma drug concentration. Permutation-based statistical testing of a mixed effect repeated measures model revealed a widespread increase in absolute CBF because of both morphine and alcohol. Conjunction analysis revealed overlapping effects of morphine and alcohol on absolute CBF in the left anterior cingulate, right hippocampus, right insula, and left primary sensorimotor areas. Effects of morphine and alcohol on relative CBF (obtained from z-normalization of absolute CBF maps) were significantly different in the left putamen, left frontoparietal network, cerebellum, and the brainstem. Corroborating previous PET results, our findings suggest that PCASL is a promising tool for central nervous system drug research.

Central nervous system effects of haloperidol on THC in healthy male volunteers

In this study, the hypothesis that haloperidol would lead to an amelioration of Δ9-tetrahydrocannabinol (THC)-induced 'psychotomimetic' effects was investigated. In a double-blind, placebo-controlled, partial three-way crossover ascending dose study the effects of THC, haloperidol and their combination were investigated in 35 healthy, male mild cannabis users, measuring Positive and Negative Syndrome Scale, Visual Analogue Scales for alertness, mood, calmness and psychedelic effects, saccadic and smooth pursuit eye measurements, electroencephalography, Body Sway, Stroop test, Visual and Verbal Learning Task, hormone levels and pharmacokinetics. Compared with placebo, THC significantly decreased smooth pursuit, Visual Analogue Scales alertness, Stroop test performance, immediate and delayed word recall and prolactin concentrations, and significantly increased positive and general Positive and Negative Syndrome Scale score, Visual Analogue Scales feeling high, Body Sway and electroencephalography alpha. Haloperidol reversed the THC-induced positive Positive and Negative Syndrome Scale increase to levels observed with haloperidol alone, but not THC-induced 'high' feelings. Compared with placebo, haloperidol significantly decreased saccadic peak velocity, smooth pursuit, Visual Analogue Scales mood and immediate and delayed word recall and significantly increased Body Sway, electroencephalography theta and prolactin levels. THC-induced increases in positive Positive and Negative Syndrome Scale but not in Visual Analogue Scales feeling high were reversed by haloperidol. This indicates that psychotic-like effects induced by THC are mediated by dopaminergic systems, but that other systems are involved in 'feeling high'. Additionally, the clear reductions of psychotic-like symptoms by a clinically relevant dose of haloperidol suggest that THC administration may be a useful pharmacological cannabinoid model for psychotic effects in healthy volunteers.

A new test to measure attentional bias and cognitive disinhibition in drinkers, based on the Hayling task

AIMS

To generate and pilot unfinished sentences, based on the Hayling Task of disinhibition, which could be completed with alcohol or non-alcohol words. To determine whether drinking habits influenced responses on the new sentences, which may advance understanding of the cognitive processes underlying alcohol-related behaviours.

METHODS

Three phases: I-Generation of appropriate sentences (via email correspondence); II-Sentence completion to establish proportion of alcohol-related and non-alcohol-related responses; III-A Hayling-style task using the sentences (laboratory-based). During the Hayling task, sentences were completed with the first word that came to mind (initiation task), and with a word that did not make semantic sense (inhibition task). In Phase III, the alcohol use disorder identification test (AUDIT) was also completed to determine whether drinking habits were related to responses.

RESULTS

Fifteen sentences were generated and tested. Compared with low hazardous drinkers, higher hazardous drinkers gave more alcohol-related responses; persisted in giving alcohol responses in the inhibition task; and were slower to make non-alcohol-related responses. A positive correlation was found between AUDIT score and number of alcohol-related responses.

CONCLUSIONS

A new alcohol-related sentence-completion tool, based upon the Hayling disinhibition task, was developed and piloted. Responses on the task were associated with measures of alcohol use disorders. The task can be used in research investigating the processes underlying the acute and chronic effects of alcohol, such as attentional bias and disinhibition. In future, the task could be used in conjunction with non-alcohol-related sentence completion tasks to investigate general and alcohol-specific processes of disinhibition.

Performance measures of alcohol-induced impairment: towards a practical ignition-interlock system for motor vehicles

Performance-based alcohol screening devices may help reduce road traffic accidents, but there is a shortage of easy-to-use performance tests available. To address this issue, four recently developed rapid, computerized, easily implementable performance tests, Spiral for iPhone and Spiral for Mac (psychomotor tests), and the Modified Mental Rotation and Catch the Rabbit tests (cognitive tests), were assessed, testing participants at predrink baseline and then during three progressive amounts of alcohol intake. Analyses showed all tests were performed statistically significantly less accurately at 0.11% blood alcohol concentrations (BACs) than at 0.00% BAC, as were all tests except Spiral for iPhone at 0.06% BAC. These results indicate the suitability of all of these tests for measuring alcohol-induced impairment, and some potential for use as a practical performance-based alcohol screening device.

Identifying experimental methods to determine the effect of pain on attention: a review of pain, caffeine, alcohol and nicotine studies

OBJECTIVES

To review published studies of the effects that pain and common psychopharmacological substances have on the attentional performance of healthy adults. To identify which attentional tasks have the greatest potential to investigate the effect of pain on attention and provide recommendations for future research.

METHODS

A search was conducted for reports of experimental studies of attention in the context of pain. This was supplemented with studies on attention and caffeine, nicotine and alcohol. Studies were included if they used a healthy adult sample, used experimental or quasi-experimental methods, were relevant to the study of attention or interruption of pain and/or examined the acute effects of a substance on attention.

RESULTS

Thirty-two papers, with 49 different experimental studies were identified (12 pain, 21 nicotine, 7 caffeine, 9 alcohol). Fourteen different tasks were reviewed across six domains of attention. The most promising measures of attention were the continuous performance task, flanker task, endogenous pre-cuing task, n-back task, inhibition task and dual task.

CONCLUSIONS

There are reliable tasks that could be used to determine the effects of pain on attention. Future research is required that develops the utility of these tasks to improve our understanding of the effects pain and analgesia have on attentional performance.

Acute alcohol impairs conditioning of a behavioural reward-seeking response and inhibitory control processes--implications for addictive disorders

AIMS

To investigate whether acute alcohol would affect performance of a conditioned behavioural response to obtain a reward outcome and impair performance in a task measuring inhibitory control to provide new knowledge of how the acute effects of alcohol might contribute to the transition from alcohol use to dependence.

DESIGN

A randomized controlled between-subjects design was employed.

SETTINGS

The laboratory of experimental psychology at the University of Sussex.

PARTICIPANTS

Thirty-two light to moderate social drinkers recruited from the undergraduate and postgraduate population.

MEASUREMENTS

After the administration of alcohol (0.8 g/kg) or placebo participants underwent an instrumental reward-seeking procedure, with abstract stimuli serving as S+ (always predicting a win of 10 pence) and S- (always predicting a loss of 10 pence). In addition, a Stop Signal task was administered before and after the administration of alcohol.

FINDINGS

Participants of the alcohol group performed the behavioural response to obtain the reward outcome more often than placebo subjects in trials associated with loss of money. This finding was observed, although alcohol was not affecting explicit knowledge of stimulus-response outcome contingencies and acquisition of conditioned attentional and emotional responses. In addition, alcohol increased Stop Signal reaction time indicating disinhibiting effects of alcohol, and this was associated positively with response probability to the S-.

CONCLUSIONS

These results demonstrate that alcohol is affecting inhibitory control of behavioural responses to external signals even when associated with punishment, contributing in this way to the transition from alcohol use to dependence.

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.

Unintended consequences of smoke-free bar policies for low-SES women in three California counties

BACKGROUND

To amplify earlier studies of unintended consequences of public policies, this article illustrates both negative and positive unanticipated consequences of smoke-free workplace policies in California bars for women of low SES.

METHODS

The article relies on thematic analysis in 2008 of qualitative data gathered between 2001 and 2007 from three mixed-method studies of tobacco use in and around bars where indoor smoking is prohibited.

RESULTS

Unanticipated consequences primarily occurred when bars did comply with the law and smokers went outside the bar to smoke, particularly when smokers stood on the street outside the bar. Key negative consequences for women who smoked outside of bars included threats to their physical safety and their public image. For women living near bars, increased smoking on the street may have increased their exposure to secondhand smoke and disruptive noise. For some women, however, unanticipated negative consequences were identified with noncompliant bars. Smokers were conjectured to congregate in the smaller number of bars where smoking was still allowed, resulting in increased exposure to secondhand smoke for low-SES women working in these bars. A common positive unintended consequence of the tobacco control ordinance was increased social circulation and solidarity, as smokers gathered outside bars to smoke.

CONCLUSIONS

Smoke-free workplace laws in bars can have both negative and positive consequences for workers and smokers, and low-income women in particular.