Stimulant alcohol effects prime within session drinking behavior

Dynamic relations among simultaneous alcohol and cannabis use, subjective responses, and problem drinking during naturally occurring drinking episodes

BACKGROUND

Simultaneous alcohol and cannabis use (SAM) is associated with riskier drinking. However, little is known regarding mechanisms of risk during drinking episodes. The current study tested whether subjective responses to simultaneous vs. alcohol-only use (i.e., high arousal positive/reward, high arousal negative/aggression, low arousal positive/relaxation, low arousal negative/impairment) were mechanisms through which SAM use was associated with daily drinking.

METHODS

Emerging adults who co-use alcohol and cannabis (N=85) completed 21 days of ecological momentary assessment with drink-contingent reports during drinking episodes. Participants reported on their simultaneous use and current subjective effects during drink reports and past-night total drinks consumed and negative consequences experienced the next morning. Three-level multilevel models (momentary, daily, person level) tested whether SAM use predicted subjective responses, and whether subjective responses mediated associations between SAM use, heavier drinking and negative consequences.

RESULTS

At the momentary and day-level, SAM (vs. alcohol-only) use predicted increased high arousal positive/rewarding, low arousal positive/relaxing, and low arousal negative/impairing subjective effects. SAM use indirectly predicted heavier day-level drinking and further negative consequences through high arousal positive/rewarding response. SAM use also indirectly predicted day-level negative consequences through low arousal negative/impairing response. At the person-level, more frequent SAM use predicted higher person-average high arousal positive/rewarding and low arousal positive/relaxing responses, and high arousal positive/rewarding response mediated relation between SAM frequency and heavier drinking.

CONCLUSIONS

Simultaneous use was associated with reward, relief, and impairment, and reward and impairment were mechanisms of risk between SAM use and riskier drinking. Findings may inform theory and just-in-time interventions seeking to reduce alcohol misuse.

Differential effects of UPPS-P impulsivity on subjective alcohol response and craving: An experimental test of acquired preparedness

Recent studies have extended the acquired preparedness model to experimental data, finding that impulsivity predicts subjective alcohol response, a related yet distinct construct from expectancies. However, studies have not tested whether specific facets of impulsivity predict subjective response, or whether impulsivity indirectly predicts alcohol craving through subjective response. Young adults who reported past-month binge drinking (N = 448) participated in a placebo-controlled alcohol administration study. Mediation models tested whether UPPS-P impulsivity facets indirectly predicted alcohol craving through subjective response on the ascending and descending limbs of the blood alcohol content (BAC). High arousal positive (e.g., sociable), low arousal positive (e.g., relaxed), high arousal negative (e.g., rude), and low arousal negative (e.g., dizzy) subjective effects were measured across limbs. Moderation by beverage condition was not detected, so models were collapsed across beverage condition. Sensation seeking indirectly predicted craving through high arousal positive subjective response on both limbs, whereas positive and negative urgency directly predicted craving. When controlling for baseline subjective response and craving, effects of sensation seeking and negative urgency on subjective response and craving became nonsignificant. The effects of positive urgency on craving remained, and an effect of positive urgency on high arousal positive effects emerged on the ascending limb. Findings suggest that relations among impulsivity, subjective response, and craving are contingent upon the specific facet of impulsivity. Interventions targeting predrink cue exposure and/or positive emotionality may be most effective for sensation seekers, whereas targeting subjective response and/or expectancies may be most efficacious for individuals high in positive urgency. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

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.

Momentary subjective responses to alcohol as predictors of continuing to drink during daily-life drinking episodes

PURPOSE

Subjective response to alcohol's stimulating and sedating effects is a person-level risk factor for heavy drinking and alcohol use disorder. Longitudinal and laboratory studies have demonstrated that at-risk individuals experience greater stimulation and lower sedation while drinking. While between-person subjective responses inform risk and etiology, in-the-moment assessments during daily-life drinking may elucidate the within-person processes by which stimulation and sedation may lead to heavier drinking. We aimed to characterize these momentary processes by testing momentary stimulation and sedation during drinking as predictors of subsequently continuing to drink during densely sampled, daily-life drinking episodes.

PROCEDURES

113 adults (54 with borderline personality disorder and 59 community participants; 77.9% female) completed ecological momentary assessment for 21 days, reporting momentary subjective stimulation and sedation throughout drinking episodes and momentary alcohol use after drink initiation (i.e., continued drinking).

FINDINGS

GLMMs demonstrated that greater day-level stimulation (OR=1.48, 95% CI=[1.20, 1.82], p<.001), greater person-level stimulation (OR=1.63, 95% CI=[1.05, 2.53], p=.031), and lower momentary sedation (OR=0.54, 95% CI=[0.41, 0.71], p<.001) predicted continued drinking.

CONCLUSIONS

Although greater stimulation and lower sedation have been conceptualized as individual-level risk factors for heavy drinking, our findings suggest that these associations are accompanied by processes that operate within person. Our results suggest that greater stimulation may confer risk for heavy drinking at the level of the drinking episode, possibly acting as positive reinforcement that may contribute to heavier drinking during future episodes. In contrast, lower sedation may primarily confer in-the-moment risk by contributing to momentary decisions to keep drinking within an episode.

The neurobiological markers of acute alcohol's subjective effects in humans

The ingestion of alcohol yields acute biphasic subjective effects: stimulation before sedation. Despite their predictive relevance to the development of alcohol use disorders (AUD), the neurobiological markers accounting for the biphasic effects of alcohol remain poorly understood in humans. Informed by converging lines of evidence, this study tested the hypothesis that alcohol ingestion acutely increases gamma-aminobutyric acid (GABA)-mediated inhibition, which would positively and negatively predict the feeling of stimulation and sedation, respectively. To do so, healthy participants (n = 20) ingested a single dose of 94% ABV alcohol (males: 1.0 ml/kg; females: 0.85 ml/kg) in a randomized placebo-controlled cross-over design. The alcohol's biphasic effects were assessed with the Brief-Biphasic Alcohol Effects Scale, and non-invasive neurobiological markers were measured with transcranial magnetic stimulation, before and every 30 min (up to 120 min) after the complete ingestion of the beverage. Results showed that acute alcohol ingestion selectively increased the duration of the cortical silent period (CSP) as compared to placebo, suggesting that alcohol increases non-specific GABAergic inhibition. Importantly, CSP duration positively and negatively predicted increases in the feeling of stimulation and sedation, respectively, suggesting that stimulation emerges as GABAergic inhibition increases and that sedation emerges as GABAergic inhibition returns to baseline values. Overall, these results suggest that modulations of GABAergic inhibition are central to the acute biphasic subjective effects of alcohol, providing a potential preventive target to curb the progression of at-risk individuals to AUD.

Changes in affect and alcohol craving during naturally occurring drinking episodes: The role of day-level drinking motives

Day-level drinking motives are associated with intensity of drinking and occurrence of negative consequences. However, little is known about how day-level drinking motives relate to alcohol craving, an approach-oriented motivational state proximal to continued drinking. This study tested whether day-level (and between-person) drinking motives were associated with craving during drinking episodes and whether this effect varied by drinking-induced changes in negative/positive affect (PA). Emerging adults (N = 114) took part in up to two waves of 21-day ecological momentary assessments. Participants reported positive/negative affect (NA) prior to and during drinking episodes, drinking motives at beginning of episodes, and craving during all drink reports. Analyses tested whether day-level and between-person (aggregated) drinking motives were associated with heightened craving and whether any effects on craving were moderated by drinking-induced changes in affect. A significant interaction emerged for day-level coping by negative affect, such that higher-than-average coping was associated with less drinking-induced craving when negative affect decreased relative to predrinking levels. However, interactions of between-person coping by negative and positive affect also emerged, such that higher person-level coping was associated with more drinking-induced craving when negative affect and positive affect increased. Day-level and between-person conformity motives by negative affect interactions were also detected, such that higher day-level and between-person conformity motives were associated with more drinking-induced craving when negative affect decreased. Relations between day-level motivation and craving may be sensitive to changes in negative/positive affect while drinking. Future research is needed to differentiate mechanisms through which person-level versus day-level motives relate to craving. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The prospective interactive effects of alcohol expectancies and subjective response on future drinking behavior

Although alcohol expectancies and subjective response are independent predictors of drinking, social-cognitive theory suggests that expectancies may distort one's subjective response, creating discrepancies between expected and actual alcohol effects. A recent cross-sectional study found that unmet expectancies (using difference scores) were associated with heavier drinking. However, cross-sectional data cannot establish temporal precedence, and using difference scores ignores important conditional main effects. As such, the current study sought to evaluate how expectancy-subjective response discrepancies predict future drinking using prospective data and an interaction approach. Participants (N = 258) were randomly assigned to consume alcohol (target BAC = .08%) within a placebo-controlled alcohol administration session. Alcohol expectancies and subjective response were assessed across the full valence by arousal affective space using parallel measures. Results indicated a significant high arousal positive (HIGH+) interaction, such that, as HIGH+ expectancies increased, individuals at low and mean levels of HIGH+ subjective response drank more heavily 12 months later. There was also a significant high arousal negative (HIGH-) interaction with a similar pattern of moderated effects. No interactions were found for low arousal effects. These results indicate that individuals with unmet HIGH+ and HIGH- expectancies drink more heavily 12 months later, controlling for prior drinking. This suggests that clinicians may consider recommending specific interventions (e.g., expectancy challenges vs. pharmacotherapy) based upon an individual's levels of expectancies and subjective response to optimize intervention efficacy. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

An Experimental Test of the Relationship between Electronic Nicotine Delivery System Use and Alcohol Consumption

BACKGROUND

Increasing research shows that the use of electronic nicotine delivery systems (ENDS) is associated with a higher rate and quantity of alcohol consumption.

METHODS

The present study used a 2-session, within-subjects design to experimentally examine the relationship between ENDS use and laboratory ad libitum alcohol consumption. A total of N = 31 (mean age = 28.71, SD = 11.17; 45.2% women; 54.8% White/Caucasian) healthy adults from the community who use ENDS and endorsed liking beer completed the study, which included a beer consumption taste-test task that assessed the volume of beer consumed by the participants across 2 counterbalanced sessions: 1 in which concurrent ENDS use was allowed and 1 in which it was not. All analyses controlled for age, race, and gender.

RESULTS

The effect of ENDS condition on the volume of beer consumed was not statistically significant, F(1, 30) = 0.03, p = 0.86). Results of linear mixed modeling showed that ENDS puffs were significantly related to alcohol sips (estimate = 0.23, SE = 0.07, p = 0.002) across the ad libitum session.

CONCLUSIONS

Overall, ENDS use did not increase alcohol consumption; however, the data suggest that ENDS puffs might act as a prime for beer sips or that these 2 behaviors are linked through habit. Future studies should more fully measure and compare global and event-level data on ENDS and alcohol use as they might show disparate patterns of relationships.

Subjective Effects of Alcohol Predict Alcohol Choice in Social Drinkers

INTRODUCTION

Alcohol is among the most commonly used psychoactive drugs, yet it can produce markedly different subjective effects in different people. Certain effects, including both heightened stimulatory effects and lesser sedative effects, are thought to predict repeated or excessive use. However, we do not fully understand the nature of these individual differences or their relationships to alcohol consumption. This controlled laboratory study examined subjective and physiologic responses to a moderate dose of alcohol in social drinkers in relation to the subjects' decision to consume alcohol.

METHODS

Healthy adult volunteers (N = 95) participated in a 5-session double-blind alcohol choice study. On the first 4 sessions, they received alcohol (0.8 g/kg) and placebo in alternating order, and on the fifth session, they chose and consumed whichever of the 2 they preferred. During each session, participants completed the Profile of Mood States (POMS) and Biphasic Alcohol Effects Scale (BAES) questionnaires and had their vitals recorded every 30 minutes. We compared subjective and physiologic response to alcohol during the sampling sessions in participants who chose alcohol or placebo on session 5.

RESULTS

Of the 95 participants, 55 chose alcohol (choosers) and 40 chose placebo (nonchoosers). In the full sample, alcohol produced its expected effects (e.g., increased friendliness, elation, and vigor (POMS), and stimulation and sedation (BAES)). The chooser and nonchooser groups did not differ in demographic characteristics, blood alcohol levels, or cardiovascular measures. However, the choosers experienced greater alcohol-induced increases in positive mood (POMS) and liked the drug more, whereas the nonchoosers experienced greater anger, anxiety (POMS), and sedation (BAES) after alcohol.

CONCLUSION

Both greater positive mood effects and lesser sedative effects after alcohol predicted preference under controlled conditions, suggesting that both factors can predict future consumption of alcohol.

The Feasibility, Tolerability, and Safety of Administering a Very High Alcohol Dose to Drinkers with Alcohol Use Disorder

INTRODUCTION

There remains a paucity of research quantifying alcohol's effects in drinkers with alcohol use disorder (AUD), particularly responses to very high alcohol doses (≥0.8 g/kg). As drinkers with AUD frequently engage in very heavy drinking (8 to 10 drinks/occasion), doses of ≤0.8 g/kg may lack ecological validity. The present study examined the feasibility, tolerability, and safety of administering a very high alcohol dose (1.2 g/kg) to non-treatment-seeking AUD participants.

METHODS

Sixty-one young adult AUD drinkers enrolled in the Chicago Social Drinking Project and completed 3 laboratory sessions at which they consumed a beverage with 1.2, 0.8, and 0.0 g/kg alcohol. Physiological responses (vital signs, nausea and vomiting, breath alcohol concentrations [BrAC]) were monitored throughout the sessions. After each session, participants completed a next-day survey of substance use, engagement in risky behaviors, and related consequences.

RESULTS

Overall, the sample demonstrated good compliance with study procedures; 93% of participants adhered to presession alcohol abstinence requirements (indicated by BrAC < 0.003 g/dl), with no participants exhibiting serious alcohol withdrawal symptoms at arrival to study visits. The 1.2 g/kg alcohol dose achieved an expected mean peak BrAC of 0.13 g/dl at 60 minutes after drinking, which was well tolerated; the majority of the sample did not experience nausea (70%) or vomiting (93%), and dose effects on vital signs were not clinically significant. Finally, we demonstrated that the 1.2 g/kg alcohol dose is safe and not associated with postsession consequences, including reduced sleep time, atypical substance use, accidents or injuries, and severe hangovers.

CONCLUSION

Results support the feasibility, tolerability, and safety of administering a very high alcohol dose to young adult drinkers with AUD within the context of a well-validated laboratory alcohol challenge paradigm. Utilizing an alcohol dose more consistent with naturalistic drinking patterns may foster greater ecological validity of laboratory paradigms for persons with moderate to severe AUD.

To Infuse or Ingest in Human Laboratory Alcohol Research

Human alcohol laboratory studies use two routes of alcohol administration: ingestion and infusion. The goal of this paper was to compare and contrast these alcohol administration methods. The work summarized in this report was the basis of a 2019 Research Society on Alcoholism Roundtable, "To Ingest or Infuse: A Comparison of Oral and Intravenous Alcohol Administration Methods for Human Alcohol Laboratory Designs." We review the methodological approaches of each and highlight strengths and weaknesses pertaining to different research questions. We summarize methodological considerations to aid researchers in choosing the most appropriate method for their inquiry, considering exposure variability, alcohol expectancy effects, safety, bandwidth, technical skills, documentation of alcohol exposure, experimental variety, ecological validity, and cost. Ingestion of alcohol remains a common and often a preferable, methodological practice in alcohol research. Nonetheless, the main problem with ingestion is that even the most careful calculation of dose and control of dosing procedures yields substantial and uncontrollable variability in the participants' brain exposures to alcohol. Infusion methodologies provide precise exposure control but are technically complex and may be limited in ecological validity. We suggest that alcohol ingestion research may not be the same thing as alcohol exposure research; investigators should be aware of the advantages and disadvantages that the choice between ingestion and infusion of alcohol invokes.

Evidence for incentive salience sensitization as a pathway to alcohol use disorder

The incentive salience sensitization (ISS) theory of addiction holds that addictive behavior stems from the ability of drugs to progressively sensitize the brain circuitry that mediates attribution of incentive salience (IS) to reward-predictive cues and its behavioral manifestations. In this article, we establish the plausibility of ISS as an etiological pathway to alcohol use disorder (AUD). We provide a comprehensive and critical review of evidence for: (1) the ability of alcohol to sensitize the brain circuitry of IS attribution and expression; and (2) attribution of IS to alcohol-predictive cues and its sensitization in humans and non-human animals. We point out gaps in the literature and how these might be addressed. We also highlight how individuals with different alcohol subjective response phenotypes may differ in susceptibility to ISS as a pathway to AUD. Finally, we discuss important implications of this neuropsychological mechanism in AUD for psychological and pharmacological interventions attempting to attenuate alcohol craving and cue reactivity.

Predictors of quickly progressing from initiating alcohol use to engaging in binge drinking among adolescents

Background

A short delay to first intoxication confers alcohol-related risk, but risk factors for a short delay have yet to be examined.

Methods

230 high school students (55.7% male; age 16.52 [1.19] years; 70.9% White) were surveyed about alcohol use. We examined whether sex, race, parental history of alcohol problems, age of onset, type of alcohol consumed, drinking company, and subjective response to alcohol were associated with 1) delay to first binge episode and 2) binge drinking status (i.e., never bingers, individuals who binge drank on their first drinking occasion, and individuals who binge drank at a later date). Finally, we examined whether first-occasion bingers reported heavier drinking and alcohol-related problems than later-occasion and never bingers.

Results

Overall, a shorter delay was associated with being male an older age of onset, and, during one's first drinking experience, consuming liquor, drinking with friends or alone, and experiencing high arousal negative alcohol effects. First-occasion bingers were more likely to be male, consume liquor, and experience stronger high arousal positive and negative alcohol effects than never bingers and to have a later age of onset, experience stronger high arousal negative, and weaker low arousal negative alcohol effects than later-occasion bingers. First-occasion bingers also reported heavier current drinking and more alcohol-related problems.

Conclusions

Characteristics of underage drinkers that confer risk for a shorter delay and first-occasion binging may provide fruitful targets for intervention, as efforts to delay binge drinking may mitigate alcohol-related risk associated with underage alcohol use.

Role Reversal: The Influence of Slot Machine Gambling on Subsequent Alcohol Consumption

Experimental studies examining the relationship between alcohol use and gambling have focused predominantly on alcohol's influence on gambling behavior. There has been little consideration of the reverse pathway: whether gambling influences subsequent alcohol use. Two experiments examined whether gambling and gambling outcomes (i.e. profits during a gambling session) influenced subsequent alcohol consumption. Experiment 1 (n = 53) used an ad libitum consumption test, in which participants could request beverages during a 30 min window. Experiment 2 (n = 29) used a beer taste test procedure, in which participants were asked to rate a series of beers. In both studies, male regular gamblers were assigned to watch a television show or play a modern slot machine for 30 min, before being provided with access to alcohol. On the ad libitum procedure, gambling significantly increased the number of alcoholic drinks ordered, the volume of alcohol consumed, the participants' speed of drinking, and their intention to drink alcohol. These effects were not corroborated using the taste test procedure. Across both studies, gambling outcomes were not associated with alcohol consumption. In conjunction with prior findings, the observation that gambling can promote alcohol consumption under certain conditions highlights a possible feedback loop whereby gambling and alcohol reinforce one another. However, the divergent results between the ad libitum and taste test experiments point to boundary conditions for the effect and raise methodological considerations for future work measuring alcohol consumption in gambling environments.

Preliminary Evidence That Real World Sleep Timing and Duration are Associated With Laboratory-Assessed Alcohol Response

BACKGROUND

Sleep timing and evening chronotype have been implicated in alcohol use problems but research has yet to study them in relation to theory-driven laboratory-based measures of alcohol use disorder risk. The current study examined (i) whether chronotype, sleep timing, and/or sleep duration are associated with alcohol response (subjective stimulation, sedation, and behavioral disinhibition) and (ii) if sex and race moderate these associations.

METHODS

Adult drinkers (N = 144; 46 female participants) completed 2 counterbalanced beverage administration sessions (alcohol and nonalcohol) during which they rated stimulation/sedation and completed a cued go/no-go task. They reported bed and waketimes over 10 days.

RESULTS

Later sleep timing was associated with greater increases in alcohol stimulation, but among male and White participants only. Later sleep timing (among male participants) and greater eveningness (examined among White male participants only) were associated with greater overall stimulation on average in the alcohol session relative to the nonalcohol session, irrespective of alcohol consumption. More variable sleep duration was associated with greater increases in sedation.

CONCLUSIONS

These findings offer preliminary, but novel evidence that sleep characteristics may relate to the relative stimulating and sedating effects of alcohol, thereby influencing the risk for alcohol problems.

Striatal activity correlates with stimulant-like effects of alcohol in healthy volunteers

Individuals who experience greater stimulation and less sedation from alcohol are at increased risk for alcohol-related problems. However, little is known regarding the neurobiological mechanisms underlying subjective response to alcohol. The current study examined the degree to which alcohol-induced brain activation correlates with ratings of stimulation and sedation, using a within-subjects, double-blind, placebo-controlled design. Participants (N = 34 healthy adults with no history of alcohol use disorder) completed three sessions: a calibration session to determine the duration of infusion needed to bring the breath alcohol to 80 mg/dl for each subject, and two counterbalanced fMRI sessions with placebo and alcohol administration. During the fMRI sessions, participants underwent 50 min scans, which included a 10 min baseline period, the IV infusion period needed to bring breath alcohol concentration (BrAC) to a peak 80 mg/dl (on the alcohol session), followed by a post-peak decline period. Participants rated their subjective stimulation and sedation at regular intervals throughout the scan. A priori VOI analyses showed that the time course of stimulation correlated with BOLD signal in the striatum. The time course of sedation did not correlate with BOLD signal in any VOIs. There were no correlations in primary visual cortex, which served as a control. These findings are the first to show that alcohol effects in the striatum are linked to the positive, stimulant-like effects of the drug and advance our understanding of the neurobiological mechanisms underlying individual differences in subjective responses to alcohol, and more broadly, risk for alcohol use disorders.

Using Placebo Beverages in Group Alcohol Studies

BACKGROUND

Placebo beverage conditions remain a key element in the methodological toolkit for alcohol researchers interested in evaluating pharmacological and nonpharmacological factors influencing the effects of alcohol consumption. While interest in experimentally examining alcohol in social context is on the rise, there has been little research examining the effectiveness of placebo manipulations in group settings, when just 1 suspicious participant could potentially jeopardize the effect of the placebo on group members. Moreover, research has rarely considered the association between individual difference factors (e.g., gender) and placebo manipulation effectiveness. The present study, using an uncommonly large sample of placebo-consuming participants, was well suited to investigate fundamental questions regarding placebo efficacy that have not been assessed previously. Specifically, we aimed to examine placebo efficacy and general processes of placebo functioning in a group context. We also assessed potential associations between a variety of individual difference factors and placebo response.

METHODS

A total of 240 participants (50% male) consumed placebo beverages during a triadic drinking period (across 80 three-person groups). Participants reported their subjective intoxication, stimulation, and sedation 8 minutes following drink consumption and estimated the alcohol content of their drink at the end of the study.

RESULTS

Participants consuming placebo beverages in groups were nearly universal in reporting that they had consumed alcohol (>99%) and had experienced an increase in feelings of intoxication [t(239) = 22.03, p < 0.001] and stimulation [t(239) = 5.53, p < 0.001], levels that were similar to those observed in prior studies conducted with participants drinking placebos in isolation. Further, participants' placebo responses were independent of their 2 group members and were largely unaffected by a variety of individual difference factors.

CONCLUSIONS

Placebo response generally operated independently of group-member influences, suggesting that researchers can successfully conduct placebo beverage studies utilizing group drinking designs.

The effects of alcohol intoxication and sexual interest on men's sexual persistence and hostility in a dating simulation

Perpetrators of sexual assault are often intoxicated; however, few experimental studies evaluate alcohol's "in the moment" effects on sexual aggression. This study extends past theory and research by examining the acute effects of alcohol on men's decisions about how to respond to sexual refusals in a dating simulation. Men (N = 62) ages 21-29 were randomly assigned to consume alcohol (target breath alcohol level 0.080%) or no alcohol. Participants were encouraged to talk to a simulated woman and act as they would on an actual date. They made choices from a list which included nonsexual and sexual options. The female agent was programmed to engage in some sexual activities but refuse others. Refusals became more intense if participants persisted. Negative binomial regression analysis was used to test a path analytic model. As predicted, participants' self-reported desire to have sex was positively associated with choosing more consensual sexual activities during the simulation (i.e., activities in which the woman willingly engaged). Consensual sexual activities were positively associated with the number of times participants persisted after the woman refused. Alcohol moderated this relationship such that it was stronger for intoxicated men than sober men. The more sexual refusals participants received, the more hostile verbal comments they made to the woman. Contrary to our predictions, this relationship was not moderated by alcohol condition. Because participants had multiple opportunities to escalate their aggression or desist, this paradigm provides new insights into the mechanisms through which intoxication enhances the likelihood of sexual aggression in dating situations.

Relationships of Impulsivity and Subjective Response to Alcohol Use and Related Problems

OBJECTIVE

Impulsivity and subjective response to alcohol are predictors of alcohol use disorder. The purpose of this study was to replicate and extend prior research examining relationships between impulsivity and subjective response patterns. In addition, impulsivity and initial subjective response patterns were examined in relation to current heavy episodic drinking and alcohol-related problems.

METHOD

Data were cross-sectional, retrospective self-reports, obtained from baseline assessments from five studies affiliated with the Yale Center for the Translational Neuroscience of Alcoholism. Analyses were conducted in a sample restricted to nondependent, young adults (n = 186) and in a larger, more heterogeneous sample (n = 363). Data were analyzed using hierarchical regression in three separate types of models.

RESULTS

In the young adult, nondependent sample, impulsivity was a statistically significant predictor of lower recent sedative subjective response. Impulsivity and initial sedative subjective response patterns were statistically significant predictors of past-year heavy drinking. Impulsivity, but not initial subjective response patterns, was a statistically significant predictor of past-year alcohol-related problems. Findings in the larger sample were similar.

CONCLUSIONS

More-impulsive individuals may perceive less sedation from alcohol, which is associated with increased heavy drinking. However, higher levels of impulsivity may be more responsible than diminished subjective response for poor decision making that results in negative drinking consequences. These results suggest that high impulsivity and certain subjective response patterns are worthy intervention targets.

Effects of acute alcohol and driving complexity in older and younger adults

RATIONALE

Our previous work demonstrated differential neurobehavioral effects of low-dose alcohol consumption on older and younger adults in a driving simulator. However, the ability to enhance or suppress a response in such context has yet to be examined.

OBJECTIVES

The current study contrasted older and younger drivers' responses to specific stimuli (i.e., relevant, irrelevant) in scenarios of differing complexity following low-dose acute alcohol administration.

METHODS

Healthy older (55-70) and younger (25-35) adults completed two driving scenarios (i.e., country and metropolis) both before and after consuming beverages targeted to reach peak BrACs of 0.00, 0.04, or 0.065%. Throughout the simulation, participants encountered relevant stimuli (e.g., pedestrians walking into the street) and irrelevant stimuli (e.g., pedestrians walking parallel). Peak deceleration, range of steering, and distance until brake application were assessed within a 450-ft window preceding each stimulus.

RESULTS

Following low-dose alcohol consumption, older adults shifted from a strategy using both deceleration and steering to relying solely on deceleration in responding to relevant stimuli in the country. Older adults under both low and moderate alcohol conditions displayed an inability to withhold responses to irrelevant stimuli in the metropolis.

CONCLUSION

These findings are consistent with our prior work showing differential effects of low-dose alcohol on older, relative to younger, adults. The interactive effects of age and alcohol, however, depend on stimulus type and environmental complexity. Continued investigation of neurobehavioral mechanisms in ecologically valid paradigms is necessary for understanding the implications of the combined impairing effects of alcohol and older age.

Naltrexone moderates the relationship between cue-induced craving and subjective response to methamphetamine in individuals with methamphetamine use disorder

RATIONALE

Reductions in cue-induced craving and subjective response to drugs of abuse are commonly used as initial outcome measures when testing novel medications for the treatment of addiction. Yet neither the relationship between these two measures at the individual level nor the moderating effects of pharmacotherapies on this relationship has been examined.

OBJECTIVE

This secondary data analysis sought to examine (1) the predictive relationship between cue-induced craving and subsequent acute subjective response to methamphetamine (MA) and (2) whether the opioid-receptor antagonist naltrexone moderated this association in a sample of non-treatment-seeking individuals who met DSM-IV criteria for MA use disorder (abuse or dependence).

METHODS

Participants (n = 30) completed two 4-day medication regimens (oral naltrexone 50 mg or placebo, in a randomized, counterbalanced, and double-blind fashion). On day 4 of each medication regimen, participants completed a cue-reactivity paradigm followed by intravenous MA administration. Methamphetamine craving was assessed after the cue-reactivity paradigm, and subjective response to MA was assessed during MA infusion.

RESULTS

Cue-induced craving for MA was positively associated with post-infusion subjective MA effects, including positive (i.e., stimulation, good effects, feel drug, high), negative (i.e., anxious and depressed), and craving-related (i.e., want more, would like access to drug, crave) responses. Naltrexone, vs. placebo, significantly reduced the association between cue-induced craving and positive subjective response to MA.

CONCLUSIONS

The findings indicate that naltrexone moderates the predictive relationship between cue-induced craving and positive subjective effects of MA, thereby suggesting a behavioral mechanism by which naltrexone may be efficacious in treating MA use disorder.

Subjective Response to Alcohol as a Research Domain Criterion

BACKGROUND

Individual differences in the subjective experience of the pharmacological effects of alcohol have long been implicated in the likelihood that one will drink heavily and develop alcoholism. The theme of this conceptual review and perspective article is to synthesize the literature on subjective responses to alcohol and to set an agenda for the next generation of research in the area. Specifically, we contend that in order for subjective response to alcohol to play a prominent role in alcoholism research, it is critical that it be studied as a multimodal phenotype.

METHODS

First, we review the human research on subjective response to alcohol measured under controlled laboratory conditions and draw recommendations for the application of these findings to understanding alcoholism neurobiology in humans. Second, we highlight multimodal approaches, including studies of the genetic and neural substrates of individual differences in subjective response to alcohol. Third, we review treatment implications with a focus on subjective response to alcohol as an intervention target. Upon review of the research on subjective response to alcohol across levels of analyses, we provide recommendations for leveraging these phenotypes in a systematic and methodologically rigorous fashion that can address central questions about alcoholism etiology, disease progression, and personalized treatment.

DISCUSSION

The approach recommended herein is largely consistent with the Research Domain Criteria (RDoC) initiative across the National Institute of Mental Health. The defining feature of such domains is that they inform behavior yet be amenable to examination through multiple units of analysis, such as molecular, genetic, circuit-level, and behavioral measurements. To that end, we contend that subjective response to alcohol represents a behaviorally and biologically plausible phenotype upon which to build using the RDoC framework for understanding alcohol use disorder.

Acute subjective response to alcohol as a function of reward and punishment sensitivity

Individual differences in subjective response to alcohol play a crucial role in the development of heavy drinking and related problems. In light of this, a growing focus of research has been identifying factors that contribute to differences in response. The aim of the present study was to determine whether individual differences in the subjective experience of rewarding and aversive effects of alcohol are a specific manifestation of general differences in reward and punishment sensitivity. Eighty-nine participants (M age=22.4, SD=1.9; 47.2% women) consumed a moderate dose of alcohol, i.e., peak breath alcohol concentration (BrAC)≈0.080g%, and rated their level of stimulation and sedation at seven timepoints over the BrAC curve. Sensitivity to reward and punishment were assessed by a self-report questionnaire prior to consumption. Multilevel growth models showed that post-consumption changes in stimulation ratings varied as a function of participants' level of reward and punishment sensitivity. Drinkers more sensitive to reward reported feeling more stimulated shortly after drinking and exhibited an attenuated rate of decline in stimulation over the blood alcohol curve, relative to drinkers with less strong reward sensitivity. Reward sensitivity was not related to subjective ratings of sedation, and punishment sensitivity was not related to either stimulation or sedation ratings. Findings suggest that reward sensitivity may increase risk for alcohol misuse among young adult social drinkers by increasing their subjective feelings of stimulation while drinking.

Current insights into the mechanisms and development of treatments for heavy drinking cigarette smokers

There is a strong association between cigarette smoking and alcohol use at the epidemiological, behavioral, and molecular levels, and this co-use creates substantial impediments to smoking cessation among smokers who are also heavy drinkers. Compared with individuals who only smoke, those who both drink and smoke heavily experience more severe health consequences and have greater difficulty in quitting smoking. During smoking abstinence, greater alcohol use is associated with decreased odds of smoking cessation, and smokers are substantially more likely to experience a smoking lapse during drinking episodes. As heavy drinking smokers are less responsive to the currently available pharmacological treatments, this subgroup of high-risk substance users possesses a unique clinical profile and treatment needs. Thus, treatment development for heavy drinking smokers represents a significant and understudied research area within the field of smoking cessation. This review will briefly describe findings from epidemiological, behavioral, and molecular studies illustrating alcohol and tobacco co-use and identify how the behavioral and neurobiological mechanisms underlying the interaction of alcohol and nicotine may inform the development of targeted treatments for this unique population of smokers.

A multilevel structural equation model of within- and between-person associations among subjective responses to alcohol, craving, and laboratory alcohol self-administration

Subjective responses to alcohol are important determinants of drinking behavior and have been linked with risk for alcohol use disorders. However, few attempts have been made to examine proximal within-person associations among state changes in subjective responses and ongoing alcohol self-administration in the laboratory. This study disaggregated within- and between-person associations among subjective responses and alcohol self-administration, while also examining the mediating role of craving and the moderating role of trait impaired control over alcohol. Sixty young heavy drinkers (mean age = 19.90, SD = 0.86) completed self-report measures including the Impaired Control Scale, then participated in a 2-hr intravenous alcohol self-administration session using the Computer-Assisted Self-infusion of Ethanol (CASE) paradigm. Repeated assessments of subjective stimulation, subjective sedation, and craving were examined in relation to ongoing in-session self-administration, as indexed by breath alcohol concentration (BrAC) assessed 15 min later. Multilevel structural equation modeling was used to isolate within-person and between-person associations. The results showed few significant associations at the between-person level, except for a direct negative association between sedation and BrAC. At the within-person level, state fluctuations in stimulation were positively associated with both craving and subsequent BrAC, whereas state changes in sedation were negatively associated with craving and positively associated with BrAC. Within-person indirect associations from subjective stimulation and sedation to subsequent BrAC mediated via craving were statistically significant. Also, participants higher on impaired control showed stronger within-person associations between craving and greater subsequent BrAC. The results suggest that subjective responses to alcohol and craving have proximal associations with self-administration behavior, the strength of which is linked with trait impaired control over alcohol.

Factor Structure of Subjective Responses to Alcohol in Light and Heavy Drinkers

BACKGROUND

Subjective responses (SRs) to alcohol have been implicated in alcoholism etiology, yet less is known about the latent factor structure of alcohol responses. The aim of this study was to examine the factor structure of SR using a battery of self-report measures during a controlled alcohol challenge.

METHODS

Nontreatment seeking drinkers (N = 242) completed an intravenous alcohol challenge including the following SR measures: Biphasic Alcohol Effects Scale, Subjective High Assessment Scale, Profile of Mood States, Alcohol Urge Questionnaire, and single items assessing alcohol "Liking" and "Wanting." Ascending limb target breath alcohol concentrations were 0.02, 0.04, and 0.06, and descending limb target was 0.04 g/dl. Exploratory factor analyses were conducted separately on estimates of mean and dose responses on the ascending limb and on descending limb data. To examine the generalizability of this factor structure, these analyses were repeated in heavy drinkers (≥14 drinks/wk for men, ≥7 for women; n = 132) and light drinkers (i.e., nonheavy drinkers; n = 110).

RESULTS

In the full sample, a 4-factor solution was supported for ascending limb mean and dose responses and descending limb data representing the following SR domains: Stimulation/Hedonia, Craving/Motivation, Sedation/Motor Intoxication, and Negative Affect. This 4-factor solution was replicated in heavy drinkers. In light drinkers, however, SR was better summarized by a 3-factor solution where ascending mean and descending limb responses consisted of Stimulation/Hedonia, Craving/Motivation, and a general negative valence factor, and dose responses consisted of a general positive valence factor, Sedation/Motor Intoxication, and Negative Affect.

CONCLUSIONS

These findings suggest that SR represents a multifaceted construct with consistent factor structure across both ascending and descending limbs. Further, as drinking levels escalate, more defined Craving/Motivation and negative valence dimensions may emerge. Longitudinal studies examining these constructs are needed to further our understanding of SR as potentially sensitive to alcohol-induced neuroadaptation.

Subjective response as a consideration in the pharmacogenetics of alcoholism treatment

Currently available pharmacological treatments for alcoholism have modest efficacy and high individual variability in treatment outcomes, both of which have been partially attributed to genetic factors. One path to reducing the variability and improving the efficacy associated with these pharmacotherapies may be to identify overlapping genetic contributions to individual differences in both subjective responses to alcohol and alcoholism pharmacotherapy outcomes. As acute subjective response to alcohol is highly predictive of future alcohol related problems, identifying such shared genetic mechanisms may inform the development of personalized treatments that can effectively target converging pathophysiological mechanisms that convey risk for alcoholism. The focus of this review is to revisit the association between subjective response to alcohol and the etiology of alcoholism while also describing genetic contributions to this relationship, discuss potential pharmacogenetic approaches to target subjective response to alcohol in order to improve the treatment of alcoholism and examine conceptual and methodological issues associated with these topics, and outline future approaches to overcome these challenges.

Energy drinks mixed with alcohol: what are the risks?

Energy drinks are popular beverages that typically include high levels of caffeine and other ingredients such as taurine, or caffeine-containing herbs, such as guarana. While energy drinks are often consumed alone, they are also frequently used as mixers for alcoholic beverages. This review summarizes what is known about the scope of use of alcohol mixed with energy drinks, the risks associated with such mixtures, and the objective laboratory data examining how the effects of their consumption differ from consuming alcohol alone. The weight of the evidence reveals that consuming alcohol mixed with energy drinks is riskier than consuming alcohol alone and constitutes a public health concern. Consumption of these mixed beverages is frequent, especially in young and underage drinkers, and compared with alcohol alone, their use is associated with elevated rates of binge drinking, impaired driving, risky sexual behavior, and risk of alcohol dependence. Laboratory research (human and animal) has demonstrated that consuming alcohol mixed with energy drinks leads to altered subjective states including decreased perceived intoxication, enhanced stimulation, and increased desire to drink/increased drinking compared to consuming alcohol alone. Possible underlying mechanisms explaining these observations are highlighted in this review.

Can energy drinks increase the desire for more alcohol?

Energy drinks, the fastest growing segment in the beverage market, have become popular mixers with alcohol. The emerging research examining the use of alcohol mixed with energy drinks (AmEDs) indicates that the combination of caffeine-containing energy drinks with alcohol may be riskier than the use of alcohol alone. The public health concerns arising from AmED use are documented in different research domains. Epidemiologic studies reveal that the consumption of AmEDs is frequent among young and underage drinkers, demographic groups that are more likely to experience the harms and hazards associated with alcohol use. In addition, for all consumers, elevated rates of binge drinking and risk of alcohol dependence have been associated with AmED use when compared to alcohol alone. Results from laboratory studies help explain why AmED use is associated with excessive intake of alcohol. When an energy drink (or caffeine) is combined with alcohol, the desire (or urge) to drink more alcohol is more pronounced in both humans and animals than with the same dose of alcohol alone. The experience of drinking alcohol appears to be more rewarding when combined with energy drinks. Given that caffeine in other foods and beverages increases preference for those products, further research on AmEDs may elucidate the underlying mechanisms that contribute to alcohol dependence.

Influence of sensation seeking on response to alcohol versus placebo: implications for the acquired preparedness model

OBJECTIVE

Previous research has identified several aspects of behavioral undercontrol that are associated with heavy drinking and problems. Further, research on the acquired preparedness model (Smith and Anderson, 2001) has identified biased learning as a potential mechanism of these effects. Traits like sensation seeking have been linked to stronger positive and weaker negative expectancies, which, in turn, contribute to increased risk for heavy drinking and problems. Although expectancies are thought to represent potentially biased expectations about drinking outcomes, they may also reflect individual differences in alcohol response. The present study examined the strength of associations between sensation seeking and both expectancies (response to placebo) and subjective response under alcohol.

METHOD

Using a between-subjects design, young adult social drinkers (N = 236) were randomly assigned to receive alcohol (target breath alcohol concentration of .08%) or placebo, after which they reported on subjective experiences of stimulation and sedation.

RESULTS

Sensation seeking was significantly related to stimulant response, and the strength of this association did not differ by beverage condition (alcohol vs. placebo).

CONCLUSIONS

The findings argue against a pharmacological explanation for results of prior studies of the acquired preparedness model and support a biased learning interpretation of relations between sensation seeking and positive expectancies. Results also extend the findings on the acquired preparedness model to an implicit measure of positive alcohol expectancies (subjective response to placebo). Future studies using additional measures of implicit expectancies (e.g., Implicit Association Test) would be helpful in determining the relative strength of implicit and explicit expectancies as mediators within the acquired preparedness model.

Relationships between impulsivity and subjective response in an IV ethanol paradigm

RATIONALE

Impulsivity and individual differences in subjective response to alcohol are risk factors for alcohol problems and possibly endophenotypes for alcohol dependence. Few prior studies have addressed relationships between the two constructs.

OBJECTIVES

To predict subjective responses to ethanol, we tested self-reported impulsiveness, ethanol dose condition (high dose, low dose, or placebo), and time (seven time points) along with interactions among these variables.

METHODS

The present study is a secondary analysis of data from a within-subject, placebo-controlled, dose-ranging ethanol administration study using IV infusion with a clamping technique to maintain steady-state breath alcohol concentration. The sample consisted of healthy, non-alcohol dependent social alcohol drinkers between the ages of 21 and 30 (N=105). Participants at varying levels of impulsivity were compared with regard to stimulant and subjective responses to three ethanol dose conditions over time.

RESULTS

Individuals with higher impulsivity reported elavated stimulant and dampened sedative response to alcohol, particularly at the higher dose. Higher impulsivity was associated with a steeper increase in stimulant effects during the first half of clamped ethanol infusion with the higher dose.

CONCLUSIONS

These results suggest that impulsive individuals may experience enhanced reinforcing, stimulant effects, and relatively muted aversive sedative effects from alcohol. These subjective responses may relate to enhanced risk of alcohol problems among more impulsive individuals.

Anxiety, sedation, and simulated driving in binge drinkers

The current study evaluated the relationships among trait anxiety, subjective response to alcohol, and simulated driving following a simulated alcohol binge. Sixty drinkers with a binge history completed the State Trait Anxiety Inventory (STAI), the Alcohol Use Questionnaire, and subsequently completed a driving simulation. Participants were then administered 0.2 g/kg ethanol at 30-min intervals (cumulative dose 0.8 g/kg). Following alcohol consumption, the Biphasic Alcohol Effects Scale (BAES) and visual analog scales of subjective impairment and driving confidence were administered, after which simulated driving was reassessed. Due to the emphasis on simulated driving after drinking in the current study, subjective response to alcohol (i.e., self-reported sedation, stimulation, impairment, and confidence in driving ability) was assessed once following alcohol consumption, as this is the time when drinkers tend to make decisions regarding legal driving ability. Alcohol increased driving speed, speeding tickets, and collisions. Sedation following alcohol predicted increased subjective impairment and decreased driving confidence. Subjective impairment was not predicted by sensitivity to stimulation or trait anxiety. High trait anxiety predicted low driving confidence after drinking and this relationship was mediated by sedation. Increased speed after alcohol was predicted by sedation, but not by trait anxiety or stimulation. Anxiety, combined with the sedating effects of alcohol, may indicate when consumption should cease. However, once driving is initiated, sensitivity to sedation following alcohol consumption is positively related to simulated driving speed.

A human alcohol self-administration paradigm to model individual differences in impaired control over alcohol use

We developed an alcohol self-administration paradigm to model individual differences in impaired control. The paradigm includes moderate drinking guidelines meant to model limits on alcohol consumption, which are typically exceeded by people with impaired control. Possible payment reductions provided a disincentive for excessive drinking. Alcohol use above the guideline, despite possible pay reductions, was considered to be indicative of impaired control. Heavy-drinking 21- to 25-year-olds (n = 39) were randomized to an experimental condition including the elements of the impaired control paradigm or to a free-drinking condition without these elements. Alcohol self-administration was compared between these two conditions to establish the internal validity of the experimental paradigm. In both conditions, participants self-administered beer and nonalcoholic beverages for 3 hours in a bar setting with 1-3 other participants. Experimental condition participants self-administered significantly fewer beers and drank to lower blood-alcohol concentrations (BACs) on average than those in the free-drinking condition. Experimental condition participants were more likely than free-drinking condition participants to intersperse nonalcoholic beverages with beer and to drink at a slower pace. Although experimental condition participants drank more moderately than those in the free-drinking condition overall, their range of drinking was considerable (BAC range = .024-.097), with several participants drinking excessively. A lower initial subjective response to alcohol and earlier age of alcohol use onset were associated with greater alcohol self-administration in the experimental condition. Given the variability in response, the impaired control laboratory paradigm may have utility for preliminary tests of novel interventions in future studies and for identifying individual differences in problem-drinking risk.

Differences in acute response to alcohol between African Americans and European Americans

BACKGROUND

Response to alcohol is a widely studied risk factor and potential endophenotype for alcohol use disorders. Research on African American response to alcohol has been limited despite large differences in alcohol use between African Americans and European Americans. Extending our previous work on the African American portion of this sample, the current study examined differences in acute subjective response to alcohol between African Americans and European Americans. Additionally, we tested whether the association between response to alcohol and past month drinking behavior and alcohol-related problems differed across race.

METHODS

One hundred and seventy-eight participants (mean age = 21.87, SD = 1.23; 57% African American) who were moderate to heavy social drinkers completed an alcohol administration study in a laboratory setting, receiving a moderate dose of alcohol (0.72 g/kg alcohol for men, 0.65 g/kg for women). Acute alcohol response was measured at 8 time points (i.e., baseline, 15, 30, 45, 60, 90, 120, and 150 minutes).

RESULTS

Latent growth curve models showed that African Americans experienced sharper increases in stimulation on the ascending limb compared to European Americans. African American women experienced sharper increases in sedation on the ascending limb compared to European American women. Change in sedation on the ascending limb was associated with past month drinking behavior. Stimulation on the ascending limb was related to alcohol problems for African Americans but not European Americans.

CONCLUSIONS

We found differences in response to alcohol across racial groups: African Americans showed a stronger response to alcohol. Future studies are needed to incorporate response to alcohol into a larger model of African American alcohol use.

The amphetamine response moderates the relationship between negative emotionality and alcohol use

BACKGROUND

Considerable evidence suggests that sensitivity to the stimulant effects of alcohol and other drugs is a risk marker for heavy or problematic use of those substances. A separate body of research implicates negative emotionality. The goal of the present study was to evaluate the independent and interactive effects of the stimulant response, assessed with an amphetamine challenge, and negative emotionality on alcohol and drug use.

METHODS

Healthy young women and men completed the Multidimensional Personality Questionnaire (MPQ) and an inventory assessing alcohol and other drug use. Subsequently, the effects of 10-mg d-amphetamine were determined in the laboratory using the Stimulant scale of the Biphasic Alcohol Effects Scale. Hierarchical regression analyses evaluated the effects of amphetamine response and the MPQ factor Negative Emotionality on measures of substance use.

RESULTS

The amphetamine response moderated relationships between negative emotionality and alcohol use: in combination with a robust amphetamine response (i.e., enhanced stimulant effects as compared with baseline), negative emotionality predicted greater alcohol consumption, more episodes of binge drinking, and more frequent intoxication in regression models. A strong stimulant response independently predicted having used an illicit drug, and there was a trend for it to predict having used alcohol. Negative emotionality alone was not associated with any measure of alcohol or drug use.

CONCLUSIONS

Consistent with the idea that emotion-based behavioral dysregulation promotes reward seeking, a high level of negative emotionality was associated with maladaptive alcohol use when it co-occurred with sensitivity to drug-based reward. The findings contribute to our understanding of how differences in personality may interact with those in drug response to affect alcohol use.

Initial development of a measure of expectancies for combinations of alcohol and caffeine: the Caffeine + Alcohol Combined Effects Questionnaire (CACEQ)

Caffeinated alcoholic beverage (CAB) consumption is widespread among young adults in the United States and is associated with increased negative consequences from alcohol. In addition to the direct pharmacological effects of adding caffeine to alcohol, another possible risk mechanism is via socially learned expectancies, which has received very little consideration. The current study conducted an initial psychometric validation of a measure of CAB expectancies to facilitate research in this area. Participants were 409 undergraduate regular drinkers (71% female) who were assessed for alcohol and CAB use, alcohol use/misuse, and expectancies about CABs. The majority (62%) of participants reported CAB experience and 48% reported CAB use in the past month. Participants primarily consumed spontaneously-prepared as opposed to premixed-CABs. More frequent CAB use was significantly positively correlated with levels of alcohol use and misuse. For the expectancy items, exploratory factor analysis revealed two factors that were labeled "Intoxication Enhancement" and "Avoid Negative Consequences." The patterns of expectancies reflected beliefs that CABs enhanced intoxication, but did not protect against negative consequences. The measure was titled the Caffeine + Alcohol Combined Effects Questionnaire (CACEQ). Intoxication enhancement scores were significantly associated with frequency of CAB use, even after adjusting for the role of weekly drinking and alcohol misuse, supporting the convergent validity of the CACEQ. These data provide initial support for the CACEQ and suggest it may be useful for clarifying the role of expectancies in CAB use. Applications for studying the risks associated with CAB use and methodological considerations are discussed.

Differentiating the contribution of pharmacological from alcohol expectancy effects to changes in subjective response and priming over successive drinks

BACKGROUND

Alcohol consumption can prime motivation to continue drinking and may contribute to excessive drinking. Most alcohol administration research assesses the effect of a single alcohol dose on outcome measures; however, this differs from typical drinking occasions in which several drinks are consumed over time. This research tracks priming measures (alcohol urge, latency to first sip, and consumption time) and subjective effects (intoxication, stimulation, and sedation) across consumption of 5 drinks, over a period of 2.5 hours. Alcohol, placebo, and no-alcohol (i.e., soft drink) conditions are compared with isolate the effects of alcohol expectancies and differentiate these from alcohol's pharmacological effects.

METHODS

Alcohol urge and subjective state were measured before and after an initial drink was consumed (preload: alcohol, placebo, or no-alcohol). Four additional drinking phases followed whereby participants had access to 2 drinks (alcohol/no-alcohol, or placebo/no-alcohol). Experimental priming (urge, latency to first sip, consumption time) and subjective effect (intoxication, stimulation, and sedation) outcomes were recorded after each drink.

RESULTS

The pattern of alcohol urge following placebo drinks differed compared with alcohol and no-alcohol consumption, Fs(1, 90) > 4.10, ps < 0.003. There was a linear decrease in urge in the no-alcohol condition, while in the alcohol condition urge increased after the first few drinks before decreasing. Urge ratings showed the opposite pattern in the placebo condition (a decrease followed by an increase). Alcohol produced the highest ratings of lightheadedness, F(5, 440) = 2.8, p < 0.02, but both alcohol and placebo produced increased sedated feelings, Fs ≥ 19.05, ps ≤ 0.001. After placebo, urge was positively related to liking and enjoying the "alcoholic" drinks and feeling more stimulated (rs ≥ 0.31, ps ≤ 0.01).

CONCLUSIONS

In social drinkers, different factors may affect priming during different stages of a drinking episode. For example, the pharmacological effects of alcohol appear involved in priming during the initial stages of drinking. When alcohol expectancies are activated, blocking access to alcohol can increase urge, supporting Tiffany's cognitive processing model of craving.

Alternative substance paradigm: effectiveness of beverage blinding and effects on acute alcohol responses

A fundamental goal of double-blind alcohol challenge studies is to reduce alcohol expectancies, though there is little research on the effectiveness of blinding procedures and their relationship to acute alcohol responses. This study examined social drinkers' perception of beverage content and related alcohol response during 3 separate double-blind experimental sessions with placebo, low-dose alcohol (0.4 g/kg), and high-dose alcohol (0.8 g/kg). Using the alternative substance paradigm, participants (N = 182) were informed that the beverage they consumed might contain alcohol, a stimulant, a sedative, or a placebo. At several time points, subjective and objective measures were obtained, and participants were asked to identify which substance they received. During both placebo and low-dose alcohol sessions, 33% and 50% of participants, respectively, did not correctly identify the beverage content; during the high-dose alcohol session, 20% did not correctly identify the beverage. Although correct and incorrect identifiers at any dose level did not differ on major background variables, drinking characteristics, or psychomotor performance during these sessions, they did differ on self-reported subjective responses, with greater sedation reported by incorrect identifiers in the placebo and high-dose conditions. In summary, results suggest that the alternative substance paradigm may be a viable option for alcohol laboratory studies, particularly for repeated sessions in within-subject designs and in cases in which the experimenter wants to reduce expectancy by not revealing a priori that alcohol is being administered.

Mixing an energy drink with an alcoholic beverage increases motivation for more alcohol in college students

BACKGROUND

There has been a dramatic rise in the consumption of alcohol mixed with energy drinks (AmEDs) in social drinkers. It has been suggested that AmED beverages might lead individuals to drink greater quantities of alcohol. This experiment was designed to investigate whether the consumption of AmEDs would alter alcohol priming (i.e., increasing ratings of wanting another drink) compared with alcohol alone.

METHODS

Participants (n = 80) of equal gender attended 1 session where they were randomly assigned to receive 1 of 4 doses (0.91 ml/kg vodka, 1.82 ml/kg energy drink, 0.91 ml/kg vodka mixed with 1.82 ml/kg energy drink [AmED], or a placebo beverage). Alcohol-induced priming of the motivation to drink was assessed by self-reported ratings on the Desire for Drug questionnaire.

RESULTS

The priming dose of alcohol increased the subjective ratings of "desire" for more alcohol, consistent with previous research that small doses of alcohol can increase the motivation to drink. Furthermore, higher desire ratings over time were observed with AmEDs compared with alcohol alone. Finally, ratings of liking the drink were similar for the alcohol and AmED conditions.

CONCLUSIONS

An energy drink may elicit increased alcohol priming. This study provides laboratory evidence that AmED beverages may lead to greater motivation to drink versus the same amount of alcohol consumed alone.

Human laboratory paradigms in alcohol research

BACKGROUND

Human laboratory studies have a long and rich history in the field of alcoholism. Human laboratory studies have allowed for advances in alcohol research in a variety of ways, including elucidating neurobehavioral mechanisms of risk, identifying phenotypically distinct subtypes of alcohol users, investigating the candidate genes underlying experimental phenotypes for alcoholism, and testing mechanisms of action of alcoholism pharmacotherapies on clinically relevant translational phenotypes, such as persons exhibiting positive-like alcohol effects or alcohol craving. Importantly, the field of human laboratory studies in addiction has progressed rapidly over the past decade and has built upon earlier findings of alcohol's neuropharmacological effects to advancing translational research on alcoholism etiology and treatment.

METHODS AND RESULTS

To that end, the new generation of human laboratory studies has focused on applying new methodologies, further refining alcoholism phenotypes, and translating these findings to studies of alcoholism genetics, medication development, and pharmacogenetics. The combination of experimental laboratory approaches with the recent developments in neuroscience and pharmacology has been particularly fruitful in furthering our understanding of the impact of individual differences in alcoholism risk and in treatment response.

CONCLUSIONS

This review of the literature focuses on human laboratory studies of subjective intoxication, alcohol craving, anxiety, and behavioral economics. Each section discusses opportunities for phenotype refinement under laboratory conditions, as well as its application to translational science of alcoholism. A summary and recommendations for future research are also provided.

Subjective response to alcohol challenge: a quantitative review

BACKGROUND

Individual differences in subjective response to alcohol, as measured by laboratory-based alcohol challenge, have been identified as a candidate phenotypic risk factor for the development of alcohol-use disorders (AUDs). Two models have been developed to explain the role of subjective response to alcohol, but predictions from the 2 models are contradictory, and theoretical consensus is lacking.

METHODS

This investigation used a meta-analytic approach to review the accumulated evidence from alcohol-challenge studies of subjective response as a risk factor. Data from 32 independent samples (total N = 1,314) were aggregated to produce quantitative estimates of the effects of risk-group status (i.e., positive family history of AUDs or heavier alcohol consumption) on subjective response.

RESULTS

As predicted by the Low Level of Response Model (LLRM), family history-positive groups experienced reduced overall subjective response relative to family history-negative groups. This effect was most evident among men, with family history-positive men responding more than half a standard deviation less than family history-negative men. In contrast, consistent with the Differentiator Model (DM), heavier drinkers of both genders responded 0.4 standard deviations less on measures of sedation than did the lighter drinkers but nearly half a standard deviation more on measures of stimulation, with the stimulation difference appearing most prominent on the ascending limb of the blood alcohol concentration curve.

CONCLUSIONS

The accumulated results from 3 decades of family history comparisons provide considerable support for the LLRM. In contrast, results from typical consumption comparisons were largely consistent with predictions of the DM. The LLRM and DM may describe 2 distinct sets of phenotypic risk, with importantly different etiologies and predictions for the development of AUDs.

Rewarding, stimulant, and sedative alcohol responses and relationship to future binge drinking

CONTEXT

Excessive consumption of alcohol is a major problem in the United States and abroad. Despite many years of study, it is unclear why some individuals drink alcohol excessively while others do not. It has been postulated that either lower or greater acute responses to alcohol, or both, depending on the limb of the breath alcohol concentration curve, contribute to propensity for alcohol misuse.

OBJECTIVE

To prospectively assess the relationship of acute alcohol responses to future binge drinking.

DESIGN

Within-subject, double-blind, placebo-controlled, multidose laboratory alcohol challenge study with intensive follow-up. Each participant completed 3 randomized sessions examining responses to a high (0.8 g/kg) and low (0.4 g/kg) alcohol dose and placebo, followed by quarterly assessments for 2 years examining drinking behaviors and alcohol diagnoses.

SETTING

Participants recruited from the community.

PARTICIPANTS

High-risk heavy social drinkers aged 21 to 35 years who habitually engage in weekly binge drinking (n = 104) and light drinker controls (n = 86).

INTERVENTION

We conducted 570 laboratory sessions with a subsequent 99.1% follow-up (1506 of 1520).

MAIN OUTCOME MEASURES

Biphasic Alcohol Effects Scale, Drug Effects Questionnaire, cortisol response, Timeline Follow-Back, Drinker Inventory of Consequences-Recent, and DSM-IV alcohol abuse and dependence.

RESULTS

Alcohol produced greater stimulant and rewarding (liking and wanting) responses and lower sedative and cortisol responses in heavy vs light drinkers. Among the heavy drinkers, greater positive effects and lower sedative effects after alcohol consumption predicted increased binge drinking frequency during follow-up. In turn, greater frequency of binge drinking during follow-up was associated with greater likelihood of meeting diagnostic criteria for alcohol abuse and dependence.

CONCLUSIONS

The widely held low level response theory and differentiator model should be revised: in high-risk drinkers, stimulant and rewarding alcohol responses even at peak breath alcohol concentrations are important predictors of future alcohol problems.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00961792.

Predictors and outcomes of variability in subjective alcohol intoxication among college students: an event-level analysis across 4 years

BACKGROUND

Individual differences in subjective alcohol intoxication, as measured by laboratory-based alcohol challenge, have been identified as a phenotypic risk factor for alcohol use disorders. Further, recent evidence indicates that subjective alcohol response is also associated with event-level physiological consequences among college students, including blackouts and hangovers.

METHODS

The current investigation tested predictors of and outcomes associated with subjective intoxication in the natural drinking environment. In a preliminary laboratory alcohol-challenge study (n = 53), we developed a brief measure of subjective alcohol intoxication for use in event-level research. Participating students in the principal study (n = 1,867; 63% women; 54% Caucasian) completed 30 days of Web-based self-monitoring in each of the 4 college years.

RESULTS

In the principal study, generalized estimating equation analyses revealed that both lighter drinking and a family history of alcohol problems predicted greater subjective intoxication after accounting for estimated blood alcohol concentration (eBAC). Moreover, greater subjective intoxication during a given drinking episode was associated with negative alcohol-related consequences, illicit drug use, and unsafe sex, and at higher eBACs, was associated with aggression, sex, and property crime. Students who on average experienced greater subjective intoxication were also more likely to experience negative consequences and engage in illicit drug use, sex, unsafe sex, and aggression.

CONCLUSIONS

These findings suggest that both within-person variability and between-person individual differences in subjective intoxication may be risk factors for adverse drinking outcomes at the event level. Intervention efforts aimed at reducing problems associated with collegiate drinking may benefit from consideration both of who experiences greater subjective intoxication and of the situations in which they are more likely to do so.

Ethanol consumption: how should we measure it? Achieving consilience between human and animal phenotypes

There is only modest overlap in the most common alcohol consumption phenotypes measured in animal studies and those typically studied in humans. To address this issue, we identified a number of alcohol consumption phenotypes of importance to the field that have potential for consilience between human and animal models. These phenotypes can be broken down into three categories: (1) abstinence/the decision to drink or abstain; (2) the actual amount of alcohol consumed; and (3) heavy drinking. A number of suggestions for human and animal researchers are made in order to address these phenotypes and enhance consilience. Laboratory studies of the decision to drink or to abstain are needed in both human and animal research. In human laboratory studies, heavy or binge drinking that meets cut-offs used in epidemiological and clinical studies should be reported. Greater attention to patterns of drinking over time is needed in both animal and human studies. Individual differences pertaining to all consumption phenotypes should be addressed in animal research. Lastly, improved biomarkers need to be developed in future research for use with both humans and animals. Greater precision in estimating blood alcohol levels in the field, together with consistent measurement of breath/blood alcohol levels in human laboratory and animal studies, provides one means of achieving greater consilience of alcohol consumption phenotypes.