Application of an alcohol clamp paradigm to examine inhibitory control, subjective responses, and acute tolerance in late adolescence

Association Between Fatty Acid Amide Hydrolase and Alcohol Response Phenotypes: A Positron Emission Tomography Imaging Study With [11C]CURB in Heavy-Drinking Youth

BACKGROUND

Reductions in fatty acid amide hydrolase (FAAH), the catabolic enzyme for the endocannabinoid anandamide, may play a role in drinking behavior and risk for alcohol use disorder. We tested the hypotheses that lower brain FAAH levels in heavy-drinking youth are related to increased alcohol intake, hazardous drinking, and differential response to alcohol.

METHODS

FAAH levels in the striatum, prefrontal cortex, and whole brain were determined using positron emission tomography imaging of [11C]CURB in heavy-drinking youth (N = 31; 19-25 years of age). C385A FAAH genotype (rs324420) was determined. Behavioral (n = 29) and cardiovascular (n = 22) responses to alcohol were measured during a controlled intravenous alcohol infusion.

RESULTS

Lower [11C]CURB binding was not significantly related to frequency of use but was positively associated with hazardous drinking and reduced sensitivity to the negative effects of alcohol. During alcohol infusion, lower [11C]CURB binding related to greater self-reported stimulation and urges and lower sedation (p < .05). Lower heart rate variability was related to both greater alcohol-induced stimulation and lower [11C]CURB binding (p < .05). Family history of alcohol use disorder (n = 14) did not relate to [11C]CURB binding.

CONCLUSIONS

In line with preclinical studies, lower FAAH in the brain was related to a dampened response to the negative, impairing effects of alcohol, increased drinking urges, and alcohol-induced arousal. Lower FAAH might alter positive or negative effects of alcohol and increase urges to drink, thereby contributing to the addiction process. Determining whether FAAH influences motivation to drink through increased positive/arousing effects of alcohol or greater tolerance should be investigated.

Holding your liquor: Comparison of alcohol-induced psychomotor impairment in drinkers with and without alcohol use disorder

BACKGROUND

Behavioral tolerance to alcohol underscores the widely accepted notion that individuals who regularly drink alcohol become less sensitive to its impairing effects. However, previous research assessing alcohol-induced impairment in humans has primarily focused on social drinkers. This has limited our understanding of the nature and extent of behavioral tolerance among heavier drinkers, such as those with alcohol use disorder (AUD).

METHODS

Data from three cohorts of the Chicago Social Drinking Project were evaluated to examine the acute effects of alcohol on psychomotor performance across the breath alcohol curve in light drinkers (LDs; n = 86), heavy drinkers (HDs; n = 208), and individuals with AUD (AUDs; n = 103). Before and at several intervals after ingesting either alcohol (0.8 g/kg, peak BrAC = 0.09 g/dL) or placebo in two random-order laboratory sessions, participants completed a test of fine motor coordination (Grooved Pegboard), a test of perceptual-motor processing (Digit Symbol Substitution Task), and a self-reported survey of perceived impairment. Sixty individuals with AUD completed a third session with a very high dose of alcohol (1.2 g/kg, peak BrAC = 0.13 g/dL).

RESULTS

The AUD and HD groups, relative to the LD group, perceived less impairment and demonstrated greater behavioral tolerance to an intoxicating dose of alcohol, exhibited by reduced peak impairment and a quicker return to baseline performance on psychomotor measures. Among individuals with AUD who consumed the very high dose, impairment was more than double that following the usual high dose, and it exceeded the impairment among LDs following the usual high dose.

CONCLUSIONS

In this sample of young adult drinkers, relative to the LD group, those with heavier drinking patterns (AUD and HD groups) showed greater behavioral tolerance to 0.8 g/kg alcohol, a dose typically associated with a binge drinking episode. However, when challenged with a very high alcohol dose commensurate with high-intensity drinking, individuals with AUD showed substantial psychomotor impairment.

Disentangling between- and within-person alcohol and expectancy effects on acute alcohol craving

OBJECTIVE

Alcohol craving is a predictor of continued drinking and a diagnostic criterion for alcohol use disorder. Rewarding subjective effects potentiate craving, but it remains unclear if relations are expectancy-driven vs. alcohol-induced. In addition, it remains unclear if relations operate solely at the person level, or if there is also within-person dynamic change.

METHODS

Participants (N = 448) come from a placebo-controlled alcohol administration study. Participants in the alcohol condition reported subjective effects and alcohol craving on ascending (BAC = .068), peak (BAC = .079), and descending (BAC = .066) BAC limbs. Participants in the placebo condition were yoked to alcohol condition participants. Multilevel models tested whether (1) within-person deviations in subjective effects predicted within-person deviations in craving, (2) between-person levels of subjective effects predicted between-person levels of craving, and (3) effects were dependent upon experimental condition.

RESULTS

At the within-person level, increases in high arousal positive/stimulant effects were associated with within-person increases in alcohol craving, regardless of experimental condition. At the between-person level, interactions were observed between high arousal positive/stimulant (and low arousal positive/relaxing) effects and condition. Probing suggested that the association between person-level high arousal positive/stimulant effects and craving was statistically significant in the alcohol but not the placebo condition. Conversely, the association between person-level low arousal positive/relaxing effects and craving was positive and statistically significant in the placebo but negative in the alcohol condition.

CONCLUSIONS

Findings suggest expectancy-like relations among high arousal positive/stimulant effects and craving within-person. However, alcohol-induced positive reinforcement (i.e., stimulation) facilitated heightened person-level craving, whereas expectancy-like negative reinforcement (i.e., relaxation) attenuated person-level craving.

Heightened motor impairment as a protective factor against heavy drinking in individuals with high alcohol-induced disinhibition

BACKGROUND

Behavioral disinhibition and motor impairment are both acutely elevated following alcohol consumption, and individual differences in sensitivity to alcohol-induced increases in these effects are associated with drinking habits. Specifically, high alcohol-induced disinhibition and low motor impairment have been identified as separate markers for alcohol-related problems. This study tested the degree to which alcohol-induced disinhibition and motor impairment jointly predict heavy drinking. We hypothesized that heavier drinkers would exhibit a combination of high sensitivity to alcohol-induced disinhibition and low sensitivity to its motor impairing effect.

METHODS

Data from three studies were aggregated to comprise a sample of 96 young adults. Participants' motor coordination (grooved pegboard) and behavioral disinhibition (cued go/no-go) were assessed following consumption of 0.65 g/kg alcohol and a placebo during separate sessions.

RESULTS

As BAC was ascending, alcohol increased motor impairment and disinhibition compared to placebo. Combined effects at this time of alcohol on motor impairment and disinhibition predicted typical drinking habits. Specifically, a combination of high sensitivity to alcohol's disinhibiting effect and low sensitivity to its motor impairing effect was associated with heavy drinking. As BAC was descending, only reduced sensitivity to motor impairment remained as a predictor of heavy drinking.

CONCLUSIONS

The findings suggest that although motor impairment following alcohol consumption is associated with certain negative outcomes (e.g., increased risk for physical injury and motor vehicle accidents), such heightened motor impairment from alcohol may actually serve as a protective factor against the excessive drinking that can accompany the disinhibiting effect of alcohol.

Pharmacodynamic determinants of hangover: An intravenous alcohol self-administration study in non-dependent drinkers

Alcohol hangover refers to the combination of negative mental and physical symptoms that can be experienced after an episode of alcohol consumption, typically emerging as blood alcohol concentration (BAC) approaches zero. Hangover has been associated with heavy drinking and may be relevant in the transition to alcohol use disorder (AUD). Our aim was to examine hangover prevalence and associated symptoms following intravenous alcohol self-administration (IV-ASA), and to identify possible predictors of hangover in non-dependent drinkers. Ninety-five drinkers without AUD completed an IV-ASA session. Pharmacodynamic measures of alcohol consumption included peak and average breath alcohol concentrations. Subjective measures of alcohol response included the Drug Effects Questionnaire and Biphasic Effects of Alcohol Scale. The Alcohol Hangover Scale assessed hangover symptoms from the end of the session until the following morning. 78% of participants endorsed at least one hangover symptom following IV-ASA. There was no association between hangover scores and IV-ASA measures of alcohol consumption. Additional mediation and moderation analysis revealed that self-reported intoxication was a significant mediator of the relationship between recent drinking and hangover symptoms. Hangover symptoms may be an early marker of the relationship between subjective response to alcohol and heavy drinking for those with no prior history of AUD. In particular, the effects of hangover go beyond exposure to alcohol and the individual's subjective response to this exposure is associated with their experience of hangover. Future studies should further characterize the determinants of hangover across different populations of drinkers to better understand the risk for AUD and inform prevention methods.

Developing a Smoking Cessation Intervention for People With Severe Mental Illness Treated by Flexible Assertive Community Treatment Teams in the Netherlands: A Delphi Study

BACKGROUND

There is still limited evidence on the effectiveness and implementation of smoking cessation interventions for people with severe mental illness (SMI) in Dutch outpatient psychiatric settings. The present study aimed to establish expert consensus on the core components and strategies to optimise practical implementation of a smoking cessation intervention for people treated by Flexible Assertive Community Treatment (FACT) teams in the Netherlands.

DESIGN

A modified Delphi method was applied to reach consensus on three core components (behavioural counselling, pharmacological treatment and peer support) of the intervention. The Delphi panel comprised five experts with different professional backgrounds. We proposed a first intervention concept. The panel critically examined the evolving concept in three iterative rounds of 90 min each. Responses were recorded, transcribed verbatim and thematically analysed.

RESULTS

Overall, results yielded that behavioural counselling should focus on preparation for smoking cessation, guidance, relapse prevention and normalisation. Pharmacological treatment consisting of nicotine replacement therapy (NRT), Varenicline or Bupropion, under supervision of a psychiatrist, was recommended. The panel agreed on integrating peer support as a regular part of the intervention, thus fostering emotional and practical support among patients. Treatment of a co-morbid cannabis use disorder needs to be integrated into the intervention if indicated. Regarding implementation, staff's motivation to support smoking cessation was considered essential. For each ambulatory team, two mental health care professionals will have a central role in delivering the intervention.

CONCLUSIONS

This study provides insight into expert consensus on the core components of a smoking cessation intervention for people with SMI. The results of this study were used for the development of a comprehensive smoking cessation program.

Subjective alcohol responses in high- and low-risk adolescents: results from the Dresden Longitudinal Study on Alcohol Use in Young Adults

BACKGROUND AND AIMS

Research shows that sensitivity to certain alcohol responses conveys risk for problem drinking. This study aimed to determine if high-risk adolescent drinkers infuse more alcohol and experience greater alcohol-induced stimulation and wanting and less sedation than low-risk adolescent drinkers.

DESIGN AND PARTICIPANTS

Ninety-two low- (n = 38) and high-risk (n = 54) adolescent drinkers, as determined by Alcohol Use Disorders Identification Test scores of < 6 or ≥ 6, respectively, participated in the Dresden Longitudinal Study on Alcohol Use in Young Adults in which intravenous alcohol self-administration was examined in a mixed within- and between-subjects design.

SETTING

Technische Universität Dresden. Dresden, Germany.

MEASUREMENTS

Predictors were drinking status (high- versus low-risk), time and their interactions. Outcomes were arterial blood alcohol concentration (aBAC); alcohol-induced stimulation, sedation and wanting assessed at baseline, 10 (alcohol prime), 45, 65, 85, 105, 125 and 145 minutes. Covariates were family history of alcohol use disorder, sex and aBAC.

RESULTS

The alcohol prime dose produced similar sharp increases in stimulation and sedation in high- and low-risk drinkers (time P < 0.001; group × time P > 0.05). During self-administration, high-risk drinkers reached higher aBACs (P = 0.028) at a faster rate (group × time P < 0.001), and experienced further increases in stimulation (group × time P = 0.005) but with similar sedation (group × time P = 0.794) than in low-risk drinkers. High-risk drinkers also exhibited greater tonic alcohol wanting (group P = 0.003) throughout the session.

CONCLUSIONS

High-risk adolescent drinkers appear to have heightened sensitivity to alcohol-induced stimulation and tonic high levels of wanting compared with low-risk adolescent drinkers.

Relations Between Acute Effects of Alcohol on Response Inhibition, Impaired Control over Alcohol Use, and Alcohol-Related Problems

BACKGROUND

Alcohol consistently impairs response inhibition in the laboratory, and alcohol impairment of response inhibition may lead to excess consumption or increases in intoxicated risk behavior, both of which contribute to risk for alcohol-related problems. To our knowledge, no prior studies have examined relations between alcohol impairment of response inhibition and either impaired control over alcohol (i.e., inability to adhere to predetermined drinking limits) or real-world alcohol-related problems. The current study addressed this gap in the literature.

METHODS

Young adult social drinkers (N = 215, 76% male) participated in a between-subjects, placebo-controlled alcohol challenge study and completed self-reports approximately 2 weeks later. Multilevel models were used to examine the hypothesis that alcohol impairment of response inhibition would indirectly lead to alcohol-related problems through impaired control over alcohol use.

RESULTS

Greater alcohol-induced impairment of response inhibition and impaired control over alcohol use were both significant predictors of alcohol-related problems. However, greater alcohol-induced response inhibition was not a significant predictor of impaired control over alcohol use.

CONCLUSIONS

To our knowledge, this is the first study demonstrating relationships between alcohol impairment of response inhibition and real-world alcohol-related problems and the first to address relationships between alcohol impairment of response inhibition and impaired control over alcohol use. These results suggest that impaired control over alcohol use may result from deficits in the trait ability to control behavior rather than deficits in alcohol-induced response inhibition. Regardless, results suggest that alcohol impairment of response inhibition and impaired control over alcohol are both worthwhile intervention targets.

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.

Poor inhibitory control is associated with greater stimulation and less sedation following alcohol

RATIONALE AND OBJECTIVE

Poor inhibitory control is a well-established risk factor for alcohol use disorder (AUD). Similarly, greater sensitivity to the stimulant effects and less sensitivity to the sedative effects of alcohol are also strongly linked to risk for AUD. Traditionally, these two risk factors have been considered to be orthogonal, and thus they have been studied independently. However, recent evidence from animal and human studies suggests that they may be related. The current study examined the relationship between inhibitory control and subjective responses to alcohol in a sample of healthy young adults.

METHODS

Moderate social drinkers (N = 69) first completed the stop signal task to assess inhibitory control. They then participated in four sessions in which they received an oral dose of ethanol (0.8 g/kg) or placebo in alternating order, providing self-report measures of stimulation and sedation on the Biphasic Alcohol Effects Scale (BAES) at regular intervals.

RESULTS

Linear mixed effects models showed that poor inhibitory control was associated with greater stimulation and less sedation following alcohol compared with placebo.

CONCLUSION

These findings provide the first direct evidence that individuals with poor inhibitory control experience greater sensitivity to the rewarding, stimulant effects of alcohol, and less sensitivity to the negative, sedative effects. These findings suggest that inhibition and subjective response to alcohol are not independent risk factors, and that together they constitute a heightened profile of risk for AUD.

Intoxicated aggression: Do alcohol and stimulants cause dose-related aggression? A review

RATIONALE

Violence and drug use are significant public health challenges that are strongly linked. It is known that alcohol plays a major role in the causation of unnatural deaths and that stimulants like cocaine and amphetamine are often implicated in aggressive acts or violence. However, a clear causal relationship between these substances and aggression, and more specifically a blood concentration threshold at which intoxicated aggression emerges is lacking. In case of a crime and subsequent law enforcement, knowledge about dose-response relationships could be of pivotal importance when evaluating the role of alcohol and drugs in aggressive offences.

AIMS

The present review aimed to determine whether there is a causal relation between intoxication with these psychoactive substances and aggression, and to define blood concentration thresholds above which these substances elicit aggression.

METHODS

Empirical articles published between 2013 and 2017 and review papers containing the predefined search strings were identified through searches in the PubMed and Embase databases and additional reference list searches. The complete search query yielded 1578 publications. Initially all articles were manually screened by title and abstract. Articles with irrelevant titles, given the selected search terms and review aims were discarded. Remaining articles were carefully studied and those that did not comply with the main objectives of this review were discarded. At the end of this process, 167 titles were found eligible for review.

FINDINGS AND CONCLUSION

While placebo-controlled experimental studies clearly showed a causal link between alcohol and aggression, it is evident that such a link has not yet been established for cocaine and amphetamines. In case of alcohol, it is clear that there are various individual and contextual factors that may contribute to the occurrence of an aggressive act during intoxication. A clear threshold blood alcohol concentration has not been defined yet for alcohol, but a statistically significant increase of aggression has been demonstrated at a dose of 0.75 g/kg and higher. Future studies into intoxicated aggression should include multiple doses of alcohol and stimulants and take into account individual and contextual factors.

Relationships between generalized impulsivity and subjective stimulant and sedative responses following alcohol administration

Impulsivity and subjective response (SR) to alcohol (i.e., individual differences in sensitivity to pharmacologic alcohol effects) are both empirically supported risk factors for alcohol use disorder; however, these constructs have been infrequently studied as related risk factors. The present investigation examined a self-report measure of impulsivity (i.e., the Barratt Impulsiveness Scale, Version 11) in relation to acute alcohol effects (i.e., stimulant and sedative SR). Participants came from 2 cohorts of the Chicago Social Drinking Project. Heavy and light drinkers from Cohort 1 (n = 156) and heavy social drinkers from Cohort 2 (n = 104) were examined using identical laboratory protocols following oral alcohol administration using a within-subject, double-blind, placebo-controlled laboratory study design. Self-reported impulsivity and, for comparison purposes, sensation seeking were measured at baseline, and SR was measured once prior to and 4 times following alcohol administration. More impulsive light, but not heavy, drinkers reported heightened stimulant SR following alcohol administration. High impulsive, light drinkers reported stimulant SR at a magnitude similar to that for heavy drinkers, whereas low impulsive, light drinkers reported limited stimulant SR. The interaction between impulsivity and sensation seeking did not statistically predict stimulant SR, and overall, impulsivity was a stronger predictor than was sensation seeking. However, impulsivity was not statistically predictive of dampened sedative SR among light or heavy drinkers. These findings partially replicate and extend the recent literature linking self-reported impulsivity to heightened stimulant SR from alcohol. Future directions include longitudinal studies and research relating multiple facets of impulsivity to SR. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Suggestibility is associated with alcohol self-administration, subjective alcohol effects, and self-reported drinking behavior

BACKGROUND

Suggestibility, defined as an individual's inclination to accept and internalize messages, has not been studied in relation to alcohol use. Peer conformity, a component of suggestibility, may be related to alcohol use, as peer groups show similarities in patterns of alcohol use. Few studies have assessed how suggestibility and peer conformity relate to alcohol self-administration or to reinforcing effects of alcohol.

AIMS

This study assessed whether suggestibility and peer conformity were associated with drinking behavior, alcohol self-administration, subjective response to alcohol, and drinking motives and expectancies.

METHODS

Study 1 participants were alcohol drinkers (n=20), who completed a laboratory study of free-access intravenous alcohol self-administration. Study 2 participants were adolescents and young adults, age 14-25 (n=150), with lifetime alcohol use. Participants completed surveys of suggestibility and drinking patterns (Study 1 and 2), subjective alcohol effects (Study 1 only), and alcohol motives and expectancies (Study 2 only).

RESULTS/OUTCOMES

In Study 1, participants with higher levels of suggestiblity self-administered more alcohol, and reported greater subjective alcohol effects. Peer conformity, though correlated with suggestibility, was not related to these measures. In Study 2, participants with higher suggestiblity reported more alcohol consumption, higher drinking motives and alcohol expectancies. Peer conformity was not related to alcohol consumption, but was related to coping and enhancement drinking motives, and all expectancies measures.

CONCLUSIONS/INTERPRETATION

Results indicate that suggestibility, beyond peer conformity, may be a critical factor to study when examining alcohol consumption behavior, and may provide insight into the development of alcohol use disorder.

Effects of alcohol intoxication on self-reported drinking patterns, expectancies, motives and personality: a randomized controlled experimental study

Alcohol intoxication may affect self-reports of alcohol use and related constructs, such as impulsivity and dependence symptoms. Improved knowledge about potential systematic reporting biases induced by alcohol, e.g. through disinhibition, may be relevant for the assessment of intoxicated individuals both in clinical routine and research. We therefore randomly assigned 54 socially drinking males aged 18 to 19 without lifetime diagnosis of DSM-IV alcohol dependence to one of two experimental arms: either placebo infusion at day 1 and alcohol infusion at day 2, or vice versa. The lab-based intravenous alcohol infusion produced a constant blood alcohol level of 0.08 percent. On each day, participants completed the Alcohol Use Disorders Identification Test, as well as other questionnaires on alcohol expectancies, drinking motives and substance use-related temperament traits. We found that alcohol significantly increased self-reported expectancies (tension reduction) and motives (conformity; η²  = .16-.23), but we observed no effect of sequence, i.e. alcohol first versus placebo first (P_corr  ≥ .118). High baseline alcohol expectancies did not moderate alcohol effects (P_corr  ≥ .462). We conclude that moderate alcohol intoxication might not generally affect the reliability of self-reported alcohol use, alcohol use problems and psychological concepts related to drinking behavior in young males without alcohol dependence. Future studies could examine larger, less selective and clinical samples for possible alcohol effects on self-report measures related to alcohol consumption.

A Review of Developmental Considerations in Human Laboratory Alcohol Research

PURPOSE OF REVIEW

Human laboratory studies involving alcohol administration have generated critical knowledge about individual differences in risk for alcohol use disorder (AUD), but have primarily involved adult populations and cross-sectional research designs. Ethical constraints have largely precluded human laboratory alcohol research in adolescence, and prospective studies have been rare. This paper provides an overview of developmental considerations in human laboratory alcohol research, with a focus on studies conducted with youth.

RECENT FINDINGS

Recent human laboratory studies from Europe and Canada have examined aspects of alcohol response during late adolescence, while recent survey studies from the United States have highlighted methods for circumventing alcohol administration in studies of adolescents.

SUMMARY

Across several decades of research, exceedingly few laboratory studies have examined developmental differences in alcohol responses or utilized prospective designs. Efforts to prioritize prospective research would further clarify the role of alcohol sensitivity traits as predictors or markers of AUD onset and progression.

A prospective study of genetic factors, human laboratory phenotypes, and heavy drinking in late adolescence

Subjective responses to alcohol are considered candidate endophenotypes for alcohol use disorder and appear to anticipate future consumption. However, prospective studies have been rare, and laboratory research has typically examined subjective responses absent measures of self-administration. This study examined the association of subjective responses with subsequent laboratory self-administration, also evaluating laboratory phenotypes in relation to putative genetic risk factors [family history (FH) of alcohol dependence and OPRM1 genotype] and subsequent heavy drinking. Participants (N = 61, M = 19.89 years, SD = 0.86) completed laboratory sessions involving intravenous alcohol challenge (Session 1) and free-access intravenous self-administration (Session 2), followed by prospective assessments. Multilevel modeling showed that higher reported stimulation and lower sedation during Session 1 independently predicted greater alcohol self-administration during Session 2. Although self-administration did not differ by FH group, participants with the OPRM1 118G allele evidenced steeper breath alcohol concentration (BrAC) trajectories and greater peak BrAC relative to 118A homozygous participants. Prospective analyses supported significant indirect associations between Session 1 subjective responses and 6-month heavy drinking via peak BrAC in Session 2. Additionally, significant indirect associations of FH (via Session 1 stimulation and Session 2 peak BrAC) and OPRM1 (via peak BrAC) with follow-up heavy drinking were observed. These results further support the utility of human laboratory phenotypes in prospective studies of alcohol use disorder risk and highlight the potential role of self-administration phenotypes in longitudinal research.

Craving and acute effects of alcohol in youths' daily lives: Associations with alcohol use disorder severity

Identifying factors associated with the progression from recreational to pathological drinking in youth holds high clinical and theoretical importance. The present study tested cross-sectional associations of alcohol use disorder (AUD) severity with putative mechanisms of AUD progression among youth ages 15-24 years, namely acute subjective effects of alcohol and craving. Male (n = 44) and female (n = 42) youth completed ecological momentary assessments when not drinking, just before drinking, and while drinking in the natural environment via handheld wireless devices. Youth were recruited from the community and were frequent and heavy drinkers, the majority (93%) with at least 1 AUD symptom (M = 3.4, SD = 2.4). Findings from youths' daily lives suggested that how youth feel while they drink depends, in part, on their severity of AUD pathology. In support of hypotheses, youths with more progressed drinking pathology (i.e., those with more symptoms of AUD) reported greater reductions in craving and tension while drinking, relative to nondrinking times. In partial support of hypotheses, males with greater AUD symptomatology reported marginally attenuated increases in stimulatory states while drinking; however, contrary to hypotheses, females with greater AUD symptomatology reported enhanced increases in stimulation while drinking. This research leveraged ecological momentary assessment methods to study subjective responses to alcohol and craving in youths' daily lives and to cross-sectionally test putative associations with AUD etiology. This work adds to literature supporting subjective responses to alcohol in the pathogenesis of alcoholism, specifically by highlighting their importance during the period in life when alcohol problems typically first emerge. (PsycINFO Database Record

Associations Between Behavioral and Neural Correlates of Inhibitory Control and Amphetamine Reward Sensitivity

Poor inhibitory control and sensitivity to drug reward are two significant risk factors for drug abuse. Although the two have been largely viewed as separate and independent risk factors, there is new evidence to suggest that they may be related at both the behavioral and neural level. This study examined associations between behavioral and neural correlates of inhibitory control and sensitivity to the subjective rewarding effects of amphetamine in humans. Healthy volunteers (n=63) first completed the stop signal task, a behavioral measure of inhibitory control. Then they participated in four sessions in which they received amphetamine (20 mg) and placebo in alternating order, providing self-report measures of euphoria and arousal at regular intervals. Finally, a subset of participants (n=38) underwent an fMRI scan to assess neural correlates of inhibitory control. In the first phase of the study, participants with longer stop signal reaction time (SSRT) reported greater amphetamine-induced euphoria and stimulation than those with shorter SSRT. In the second phase, fMRI of response inhibition showed the expected activation in right prefrontal regions. Further, individuals who exhibited less activation in the right middle frontal gyrus during the inhibition task reported more euphoria during the amphetamine sessions. This study is the first to show associations between poor inhibitory control and amphetamine reward sensitivity at both behavioral and neural levels in humans. These findings extend our understanding of risk for drug abuse in individuals with poor inhibitory control and suggest novel targets for prevention efforts.

A systematic review of the evidence for acute tolerance to alcohol - the "Mellanby effect"

OBJECTIVE

To review the evidence for "the Mellanby effect", that is, whether the response to a given blood alcohol concentration (BAC) is more marked when BAC is rising than at the same concentration when BAC is falling.

METHODS

We systematically searched the databases EMBASE, Medline, and Scopus up to and including December 2016 using text words "tolerance", "ascending", "descending" or "Mellanby" with Medline term "exp *alcohol/" or "exp *drinking behavior/" or equivalent. Articles were identified for further examination by title or abstract; full text articles were retained for analysis if they dealt with acute (within dose) alcohol tolerance in human subjects and provided quantitative data on both the ascending and descending parts of the BAC-time curve. Reference lists of identified works were scanned for other potentially relevant material. We extracted and analyzed data on the subjective and objective assessment of alcohol effects.

RESULTS

We identified and screened 386 unique articles, of which 127 full-text articles were assessed; one provided no qualitative results, 62 involved no human study, 25 did not consider acute tolerance within dose, and 13 failed to provide data on both ascending and descending BAC. We extracted data from the 26 remaining articles. The studies were highly heterogeneous. Most were small, examining a total of 770 subjects, of whom 564 received alcohol and were analyzed in groups of median size 10 (range 5-38), sometimes subdivided on the basis of drinking or family history. Subjects were often young white men. Doses of alcohol and rates of administration differed. Performance was assessed by at least 26 different methods, some of which measured many variables. We examined only results of studies which compared results for a given alcohol concentration (C) measured on the ascending limb (C_up) and the descending limb (C_down) of the BAC-time curve, whether in paired or parallel-group studies. When subjects were given alcohol in more than one session, we considered results from the first session only. Rating at C_down was better than at C_up for some measures, as expected if the Mellanby effect were operating. For example, subjects rated themselves less intoxicated on the descending limb than at the same concentration on the ascending limb in 12/13 trials including 229 subjects that gave statistically significant results. In 9 trials with a total of 139 subjects, mean difference could be calculated; weighted for study size, it was 29% [range 24-74%]. Willingness to drive was significantly greater in 4 of 6 studies including a total of 105 subjects; weighted mean difference increased by 207% [range 79-300%]. By contrast, measure of driving ability in three groups of a total of 200 trials in 57 subjects showed worse performance by a weighted mean of 96% [range 3-566%]. In three trials that tested inhibitory control (cued go or no-go response times), weighted mean performance was 30% [range 14-65%] worse on the descending limb.

CONCLUSIONS

The "Mellanby effect" has been demonstrated for subjective intoxication and willingness to drive, both of which are more affected at a stated ethanol concentration when BAC is rising than at the same concentration when BAC is falling. By contrast, objective measures of skills necessary for safe driving, such as response to inhibitory cues and skills measured on driving simulators, were generally worse on the descending part of the BAC-time curve for the same BAC.

Association between overall rate of change in rising breath alcohol concentration and the magnitude of acute tolerance of subjective intoxication via the Mellanby method

OBJECTIVE

The magnitude of acute tolerance is a strong predictor of the development of longer-term chronic tolerance and plays a decisive role in risky decisions (e.g., driving after drinking). Therefore, it is important to identify factors that increase the magnitude of this adaptive process. This study explored whether acute tolerance magnitude varied as a function of the overall rate of increase in breath alcohol concentration (BrAC).

METHODS

Twenty-nine young adult social drinkers (M age = 22.55, SD = 3.10; 62.1% women) consumed a moderate dose of alcohol (men: 0.86 g/kg, women: 0.75 g/kg) in a controlled laboratory setting. Subjective intoxication was assessed at matched BrACs (~0.060 g/dl) on each limb of the BrAC curve.

RESULTS

Hierarchical regression results indicated that faster overall increases in BrAC on the ascending limb were associated with greater acute tolerance for subjective intoxication ratings (p < .01, R²  = .29).

CONCLUSIONS

These results present some of the first evidence that faster increases in BrAC may be associated with greater acute tolerance, as indicated by greater reduction in subjective intoxication across the limbs of the BrAC curve. This greater reduction may, in turn, promote heavier drinking and/or engagement in behaviors for which one is unfit (e.g., driving after drinking).

Drinking Motives Predict Subjective Effects of Alcohol and Alcohol Wanting and Liking During Laboratory Alcohol Administration: A Mediated Pathway Analysis

BACKGROUND

Motivational models of alcohol use suggest that individual differences in sensitivity to the acute subjective effects of alcohol play an important role in motivational pathways to alcohol use. However, few studies have examined the link between drinking motives and subjective responses to alcohol. This study investigated the associations of coping and enhancement drinking motives with subjective stimulant and sedative effects during a laboratory alcohol administration session. We also examined whether stimulation and sedation following alcohol administration mediated the relationships between drinking motives and postalcohol ratings of alcohol wanting and liking.

METHODS

Heavy episodic drinkers (n = 147, ages 19 to 25) at 2 sites participated in an intravenous alcohol administration session in which blood alcohol concentration was raised to a target of 80 mg% over 20 minutes. Participants completed measures of stimulation and sedation at baseline and 20 minutes and also rated alcohol liking and wanting at 20 minutes. Drinking motives and alcohol use were assessed during a previous laboratory visit.

RESULTS

A path analysis controlling for baseline stimulation and sedation showed that enhancement motives were positively associated with postalcohol stimulation and negatively associated with postalcohol sedation. In contrast, coping motives were positively associated with postalcohol sedation. In turn, postalcohol stimulation, but not sedation, was associated with alcohol wanting and liking. Further, indirect pathways from enhancement motives to postalcohol wanting and liking mediated through postalcohol stimulation were statistically significant. Coping motives, on the other hand, were directly associated with increased postalcohol wanting and liking.

CONCLUSIONS

The results demonstrate that drinking motives are linked with individual differences in sensitivity to the effects of alcohol, which may serve as a mechanism underlying alcohol reinforcement and the motivation to consume more alcohol during a drinking episode.

Multisensory Stop Signals Can Reduce the Disinhibiting Effects of Alcohol in Adults

BACKGROUND

Alcohol impairs drinkers' abilities to inhibit inappropriate responses. Certain stimulus conditions have been shown to facilitate behavioral control. Under conditions where individuals are presented with multiple inhibitory signals, the speed and consistency with which they are able to inhibit a response is improved. Recent research has shown that multisensory signals might protect against the disruptive effects of alcohol on mechanisms of behavioral control. This study examined whether multisensory stop signals can be used to improve inhibitory control, possibly by speeding attentional shifts toward inhibitory "stop" signals in the environment.

METHODS

Twenty adult social drinkers performed a modified cued go/no-go task that measured the ability to inhibit prepotent responses following 0.64 g/kg alcohol and placebo. Response targets were presented as unimodal (visual) and as multisensory (visual + aural) stimuli.

RESULTS

Results showed that during unimodal response target trials, participants made more inhibitory failures under 0.64 g/kg alcohol compared to placebo. During multisensory trials, however, there was no significant effect of alcohol on inhibitory control.

CONCLUSIONS

These findings identify multisensory inhibitory signals as a potentially important environmental factor that can reduce the degree to which alcohol disinhibits behavior possibly by intersensory co-activation between the visual and auditory pathways.

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.