Alcohol challenge responses predict future alcohol use disorder symptoms: a 6-year prospective study

Interpretations and experiences of subjective effects for alcohol alone and when combined with cannabis: A mixed-methods approach

Subjective effects generally describe the feelings one has when consuming substances. There are several tools available for measuring alcohol-related subjective effects but there are reasons to believe that effects are interpreted differently across participants. The assessment of alcohol-related subjective effects is further complicated by the fact that many people use other substances with alcohol, including cannabis. The present study used a mixed-methods approach to evaluate interpretations of 21 subjective effects used in common assessments among a college student sample (N = 99; primarily White [79%], Hispanic [60%] women [74%], 72% of which reported lifetime couse of alcohol and cannabis). We sought to (a) estimate the prevalence of each effect and the amount of alcohol/number of drinks (and, for those with simultaneous use, amount of cannabis/number of hits) required to experience each effect and (b) evaluate how participants interpreted each effect that they had ever experienced when drinking (for our sample who had used only alcohol) or when simultaneously using alcohol and cannabis (for our sample who had reported simultaneous use). Across both samples, we found that several effects were far more common than others and participants had varied interpretations of each subjective effect. Further, qualitative results demonstrated that participants interpreted some subjective effects in a way that differed from the original intention of the measure. Results suggest a degree of measurement error when using common subjective effects assessment tools. Findings lay the groundwork for standardized measures of subjective effects for simultaneous use and have implications for future real-world assessment and intervention work. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Network meta-analysis of the molecular mechanisms and signaling pathways underlying alcohol-induced thymic atrophy

BACKGROUND

Thymic atrophy is characterized by loss of thymocytes, destruction of thymic architecture, and a subsequent decrease in naïve T cells with compromised immunity. Thymic atrophy occurs during aging. Environmental factors including alcohol misuse also induce thymic atrophy. Despite the link between alcohol misuse and thymic atrophy, the underlying mechanism is understudied. We aimed to identify molecules and signaling pathways that underly alcohol-induced thymic atrophy during aging.

METHODS

F344 rats were given 3-day binge-ethanol (4.8 g/kg/day; 52% w/v; i.g.) and the thymus was collected and weighed. Molecular mechanisms underlying ethanol-induced thymic atrophy were investigated by network meta-analysis using the QIAGEN Ingenuity Pathway Analysis (IPA). The molecules associated with ethanol were identified from the QIAGEN Knowledge Base (QKB) and those associated with thymic atrophy were identified from QKB and Mouse Genome Informatics (MGI). Aging-mediated Differential Expression Genes (DEGs) from mouse thymocytes were obtained from the Gene Expression Omnibus (GEO) database (GSE132136). The relationship between the molecules and associated signaling pathways were studied using IPA.

RESULTS

Binge-ethanol decreased thymic weight in F344 rats. Our meta-analysis using IPA identified molecules commonly shared by ethanol and thymic atrophy through which simulation with ethanol increased thymic atrophy. We then obtained aging-mediated DEGs from the atrophied thymocytes. We found that ethanol contributed to thymic atrophy through modulation of the aging-mediated DEGs. Our network meta-analysis suggests that ethanol may augment thymic atrophy through increased expression of cytokines (e.g., IL-6, IL-17A and IL-33) along with their regulators (e.g., STAT1 and STAT3).

CONCLUSIONS

Exposure to alcohol may augment thymic atrophy by altering the activity of key inflammatory mediators, such as STAT family members and inflammatory cytokines. These findings provide insights into the signaling pathways and upstream regulators that underly alcohol-induced thymic atrophy during aging, suggesting that alcohol consumption could prepone thymic atrophy.

Sex differences in oxycodone-taking behaviors are linked to disruptions in reward-guided, decision-making functions

Problematic opioid use that emerges in a subset of individuals may be due to pre-existing disruptions in the biobehavioral mechanisms that regulate drug use. The identity of these mechanisms is not known, but emerging evidence suggests that suboptimal decision-making that is observable prior to drug use may contribute to the pathology of addiction and, notably, serve as a powerful phenotype for interrogating biologically based differences in opiate-taking behaviors. The current study investigated the relationship between decision-making phenotypes and opioid-taking behaviors in male and female Long Evans rats. Adaptive decision-making processes were assessed using a probabilistic reversal-learning task and oxycodone- (or vehicle, as a control) taking behaviors assessed for 32 days using a saccharin fading procedure that promoted dynamic intake of oxycodone. Tests of motivation, extinction, and reinstatement were also performed. Computational analyses of decision-making and opioid-taking behaviors revealed that attenuated reward-guided decision-making was associated with greater self-administration of oxycodone and addiction-relevant behaviors. Moreover, pre-existing impairments in reward-guided decision-making observed in female rats was associated with greater oxycodone use and addiction-relevant behaviors when compared to males. These results provide new insights into the biobehavioral mechanisms that regulate opiate-taking behaviors and offer a novel phenotypic approach for interrogating sex differences in addiction susceptibility and opioid use disorders.

Do sleep and circadian characteristics predict alcohol use in adult drinkers?

BACKGROUND

While sleep and circadian rhythms are recognized contributors to the risk for alcohol use and related problems, few studies have examined whether objective sleep and circadian measures can predict future alcohol use in humans, and no such studies have been conducted in adults. This study examined whether any baseline sleep and/or circadian characteristics of otherwise healthy adults predicted their alcohol use over the subsequent 12 months.

METHODS

Participants (21-42 years) included 28 light and 50 heavy drinkers. At baseline, a comprehensive range of self-reported and objective sleep/circadian measures was assessed via questionnaires, wrist actigraphy, and measurement of dim light melatonin onset and circadian photoreceptor responsivity. Following this, the number of alcoholic drinks per week and binge drinking episodes per month were assessed quarterly over the subsequent 12 months. Anticipated effects of alcohol (stimulation, sedation, and rewarding aspects) were also assessed quarterly over the 12 months. Analyses included generalized linear mixed-effects models and causal mediation analysis.

RESULTS

Across the range of measures, only self-reported insomnia symptoms and a longer total sleep time at baseline predicted more drinks per week and binges per month (ps <0.02). There was a trend for the anticipated alcohol effect of wanting more alcohol at the 6-month timepoint to mediate the relationship between insomnia symptoms at baseline and drinks per week at 12 months (p = 0.069).

CONCLUSIONS

These results suggest that in otherwise healthy adults, insomnia symptoms, even if subclinical, are a significant predictor of future drinking, and appear to outweigh the influence of circadian factors on future drinking, at least in otherwise healthy adults. Insomnia symptoms may be a modifiable target for reducing the risk of alcohol misuse.

A translational rodent model of individual differences in sensitivity to the aversive properties of ethanol

BACKGROUND

A strong relationship exists between individual sensitivity to the aversive properties of ethanol and risk for alcohol use disorder (AUD). Despite this, our understanding of the neurobiological mechanisms underlying the subjective response to ethanol is limited. A major contributor to this lack of knowledge is the absence of preclinical models that enable exploration of this individual variability such as is possible in studies of humans.

METHODS

Adult male and female Long-Evans rats were trained to associate a novel tastant (saccharin) with acute exposure to either saline or ethanol (1.5 g/kg or 2.0 g/kg i.p.) over three conditioning days using a standard conditioned taste aversion (CTA) procedure. Variability in sensitivity to ethanol-induced CTA was phenotypically characterized using a median split across the populations studied.

RESULTS

When examining group averages, both male and female rats exposed to saccharin paired with either dose of ethanol exhibited lower saccharin intake relative to saline controls indicative of ethanol-induced CTA. Examination of individual data revealed a bimodal distribution of responses uncovering two distinct phenotypes present in both sexes. CTA-sensitive rats exhibited a rapid and progressive reduction in saccharin intake with each successive ethanol pairing. In contrast, saccharin intake was unchanged or maintained after an initial decrease from baseline levels in CTA-resistant rats. While CTA magnitude was similar between male and female CTA-sensitive rats, among CTA-resistant animals females were more resistant to the development of ethanol-induced CTA than males. Phenotypic differences were not driven by differences in baseline saccharin intake.

CONCLUSIONS

These data parallel work in humans by revealing individual differences in sensitivity to the aversive properties of ethanol that emerge immediately after initial exposure to ethanol in both sexes. This model can be used in future studies to investigate the neurobiological mechanisms that confer risk for AUD.

High-intensity sweet taste as a predictor of subjective alcohol responses to the ascending limb of an intravenous alcohol prime: an fMRI study

High-intensity sweet-liking has been linked to alcohol use disorder (AUD) risk. However, the neural underpinning of this association is poorly understood. To find a biomarker predictive of AUD, 140 participants (social and heavy drinkers, ages 21-26) underwent functional magnetic resonance imaging (fMRI) during a monetary incentive delay (MID) task and stimulation with high (SucroseHigh)- and low-concentration sucrose, as well as viscosity-matched water. On another day after imaging, and just before free-access intravenous alcohol self-administration, participants experienced a 30 mg% alcohol prime (10 min ascent) using the Computerized Alcohol Infusion System. Principal component analysis (PCA) of subjective responses (SR) to the prime's ascending limb generated enjoyable (SRenjoy) and sedative (SRsed) intoxication components. Another PCA created one component reflective of self-administered alcohol exposure (AE) over 90 min. Component loadings were entered as regressors in a voxel-wise general linear fMRI model, with reward type as a fixed factor. By design, peak prime breath alcohol concentration was similar across participants (29 ± 3.4 mg%). SRenjoy on the prime's ascending limb correlated positively with [SucroseHigh > Water] in the supplementary motor area and right dorsal anterior insula, implicating the salience network. Neither SR component correlated with the brain's response to MID. AE was unrelated to brain reward activation. While these findings do not support a relationship between alcohol self-administration and (1) subjective liking of or (2) regional brain response to an intensely sweet taste, they show that alcohol's enjoyable intoxicating effects on the rising limb correspond with anterior insular and supplementary motor area responses to high-concentration sucrose taste. No such associations were observed with MID despite robust activation in those regions. Insula and supplementary motor area responses to intense sensations relate to a known risk factor for AUD in a way that is not apparent with a secondary (monetary) reward.

A multicomponent ethanol response battery across a cumulative dose ethanol challenge reveals diminished adolescent rat ethanol responsivity relative to adults

Adolescence is a conserved developmental period associated with low alcohol responsivity, which can contribute to heavy drinking and development of an alcohol use disorder (AUD) later in life. To investigate ethanol responsivity between adolescent and adult rats, we developed an ethanol response battery (ERB) to assess acute ethanol responses across cumulative doses of ethanol during the rising phase of the blood ethanol curve. We tested the hypothesis that adolescent male and female rats would exhibit lower ethanol responsivity to a cumulative ethanol challenge relative to adults. Male and female adolescent (postnatal day [P]40) and adult (P85) Wistar rats underwent ERB assessment following consecutive doses of ethanol (i.e., 1.0, 1.0, and 1.0 g/kg) to produce cumulative ethanol doses of 0.0, 1.0, 2.0, and 3.0 g/kg. The ERB consisted of (1) the 6-point behavioral intoxication rating scale, (2) body temperature assessment, (3) tail blood collection, (4) accelerating rotarod assessment, (5) tilting plane assessment, and (6) loss of righting reflex (LORR) assessment. Across cumulative ethanol doses, adolescent and adult rats evidenced progressive changes in ERB measures. On the ERB, adolescent rats of both sexes evidenced (1) lower intoxication rating, (2) blunted hypothermic responses, particularly in females, (3) longer latencies to fall from the accelerating rotarod, and (4) less tilting plane impairment relative to adults despite comparable BECs. All adult rats, regardless of sex, displayed a LORR at the 3.0 g/kg cumulative ethanol dose while among the adolescent rats, only one male rat and no females showed the LORR. These data reveal decreased adolescent ethanol responsivity across body temperature, intoxication, balance, and coordination responses to a cumulative ethanol challenge as assessed using the novel ERB relative to adults. The results of this study suggest that adolescent-specific low ethanol responsivity may contribute to adolescent binge drinking and increased risk for development of an AUD.

Ventral prefrontal network response to alcohol in young adults with bipolar disorder: a within-subject randomized placebo-controlled alcohol administration study

Bipolar disorder co-occurs with alcohol use disorder at a rate 3-5 times higher than the general population. We recently reported that individuals with bipolar disorder differ in the positive stimulating and anxiolytic effects of alcohol compared with healthy peers. This study used a randomized, placebo-controlled, cross-over, within-subject alcohol administration design to investigate neurobiological mechanisms within ventral prefrontal cortical (vPFC) systems that may underlie altered sensitivity to alcohol in bipolar disorder (NCT04063384). Forty-seven young adults (n = 23 with bipolar disorder, 64% women) completed clinical assessment and two beverage administration sessions (alcohol and placebo, counter-balanced). Participants were dosed to 0.08 g% breath alcohol concentration during the alcohol condition and completed measures of subjective response to alcohol and an emotional processing fMRI task during the ascending limb. Timing during the placebo condition mirrored the alcohol session. Acute alcohol was associated with reduced functional connectivity between the insula - subcallosal cingulate cortex, and increased connectivity between the left nucleus accumbens - ventromedial PFC in bipolar disorder, but with no change in functional connectivity between these regions in healthy peers. Alcohol-related increases in nucleus accumbens - ventromedial PFC functional connectivity was associated with greater positive stimulating effects of alcohol in bipolar disorder and heavier recent alcohol use. Results suggest vPFC brain systems respond differently to acute alcohol during emotional processing in young adults with bipolar disorder compared with healthy peers, and that vPFC system responses relate to the subjective experience of intoxication and recent alcohol use.

Retrospective self-reports of sensitivity to the effects of alcohol: Trait-like stability and concomitant changes with alcohol involvement

OBJECTIVE

Lower sensitivity to the acute effects of alcohol is known to confer risk for the development of alcohol use disorder. Alcohol sensitivity, or level of response to alcohol's subjective effects, is heritable but also can change as a result of persistent alcohol exposure (i.e., acquired tolerance). Here, we examined how changes over time in four indices of alcohol involvement affected scores on two validated, retrospective self-report measures of alcohol response-the Self-Rating of the Effects of Alcohol (SRE) form and the Alcohol Sensitivity Questionnaire (ASQ)-in a sample of emerging adult drinkers.

METHOD

Participants (N = 173; Mage = 19.5 years; 60% assigned female at birth) completed the ASQ, SRE, and measures of alcohol use and problems at two time points separated by a median of 0.77 years (range: 0.30-2.54 years).

RESULTS

Multiple linear regression showed that increases in drinking over this period accounted for increases in SRE and ASQ scores (i.e., in reported numbers of drinks needed to experience subjective effects of alcohol). Increased drinking accounted for more variance in the number of drinks needed to experience lighter drinking versus heavier drinking effects, and increases in the number of drinks consumed per occasion had a larger effect than did changes in total numbers of drinks consumed, number of binge-drinking occasions, or drinking-related problems.

CONCLUSIONS

Findings suggest that both SRE and ASQ capture some stable, trait-like variability in alcohol response as well as some state-dependent, within-person variability in alcohol response acquired through increases in alcohol involvement. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Laboratory and Real-World Experimental Approaches to Understanding Alcohol Relapse

Alcohol use disorder is highly prevalent and high risk of relapse remains a significant treatment challenge. Therefore, the utility of human laboratory models of relapse to further the understanding of psychobiological mechanisms that precipitate relapse risk and allow testing of novel interventions could be of benefit in expediting the development of effective treatments to target high relapse risk. Stress is a risk factor for the development of AUD and for relapse, and furthermore, chronic alcohol use leads to adaptations in central and peripheral stress biology. Here, we review our efforts to assess the integrity of these stress pathways in individuals with alcohol use disorder and whether adaptations in these systems play a role in relapse risk. Using validated human laboratory procedures to model two of the most common situations that contribute to relapse risk, namely stress and alcohol cues, we review how such models in the laboratory can predict subsequent relapse, and how we can measure specific identified biobehavioral markers of relapse effectively and ecologically in the real world. Finally, we discuss the significant implications of these findings for the development of novel and effective interventions that target stress dysregulation and craving as risk factors to treatment.

A preliminary investigation of salivary α-amylase as a novel biomarker of subjective response to alcohol: A brief report

Alcohol misuse represents a universal public health concern that spans multiple demographics. As such, understanding shared, biological indicators of alcohol-related risk is vital to implementing targeted prevention and intervention efforts. Self-report measures of subjective response to alcohol (SR) capture both psychological and pharmacological effects of alcohol and robustly predict patterns of alcohol use, negative consequences, and the development of alcohol use disorders. Importantly, several biological markers of alcohol's sedating effects, including cortisol, have been identified and complement subjective response assessments. However, biological markers of alcohol's stimulating effects are less understood. Studies have implicated alcohol-induced changes in heart rate as a viable marker, but heart rate measurements are susceptible to measurement error. Salivary α-amylase, a reliable indicator of sympathetic nervous system activation, represents a promising alternative biomarker of alcohol-induced stimulation. Using data from a large, placebo-controlled alcohol administration study (N = 448), the present study examined the extent to which α-amylase is a viable marker of alcohol-induced stimulation. To test this, a measurement model was estimated in which baseline and ascending limb subjective stimulation latent variables were created using two validated measures of subjective response. Ascending self-reports of stimulation and levels of α-amylase were then regressed onto beverage conditions and allowed to correlate with each other. Findings indicated that α-amylase is sensitive to acute alcohol consumption and is positively, but not statistically reliably, related to the ascending limb stimulant SR. Future studies should consider including salivary α-amylase as a noninvasive physiological indicator of alcohol's stimulating effects. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Appetitive and aversive cue reactivities differentiate neural subtypes of alcohol drinkers

Craving reflects the subjective urge to use drugs and can be triggered by both positive and negative emotional states. No studies have systematically investigated the relative roles of these mechanisms in the pathophysiology of substance misuse. Here, we performed meta-analyses of drug cue-elicited reactivity and win and loss processing in the monetary incentive delay task to identify distinct neural correlates of appetitive and aversive responses to drug cues. We then characterized the appetitive and aversive cue responses in seventy-six alcohol drinkers performing a cue craving task during fMRI. Imaging data were processed according to published routines. The appetitive circuit involved medial cortical regions and the ventral striatum, and the aversive circuit involved the insula, caudate and mid-cingulate cortex. We observed a significant correlation of cue-elicited activity (β estimates) of the appetitive and aversive circuit. However, individuals varied in appetitive and aversive cue responses. From the regression of appetitive (y) vs. aversive (x) β, we identified participants in the top 1/3 each of those with positive and negative residuals as "approach" (n = 15) and "avoidance" (n = 11) and the others as the "mixed" (n = 50) subtype. In clinical characteristics, the avoidance subtype showed higher sensitivity to punishment and, in contrast, the approach subtype showed higher levels of sensation seeking and alcohol expectancy for social and physical pressure. The findings highlighted distinct neural underpinnings of appetitive and aversive components of cue-elicited reactivity and provided evidence for potential subtypes of alcohol drinkers.

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.

Stimulant-like subjective effects of alcohol are not related to resting-state connectivity in healthy men

Individual differences in subjective, stimulant-like effects of alcohol are associated with the risk of developing alcohol use disorder. Specifically, individuals who experience more pronounced stimulant-like effects from alcohol are more likely to continue and escalate their usage. The neural basis for these individual differences in subjective response is not yet known. Using a within-subject design, 27 healthy male social drinkers completed three fMRI scans after ingesting a placebo, 0.4 and 0.8 g/kg alcohol, in a randomized order under double-blind conditions. Subjective stimulant effects of alcohol were assessed at regular intervals during each session. Seed-based and regional homogeneity analyses were conducted to evaluate changes in resting-state functional connectivity in relation to the stimulant effect of alcohol. Results indicated that 0.4 g/kg alcohol increased the connectivity to thalamus, and 0.8 g/kg alcohol decreased the connectivity to ventral anterior insula, primarily from the superior parietal lobule. Both doses reduced regional homogeneity in the superior parietal lobule but without an exact overlap with clusters showing connectivity changes in the seed-based analyses. The self-reported stimulant effect of alcohol was not significantly related to changes in seed-based connectivity or regional homogeneity. These findings suggest that alcohol-induced stimulation effects are not related to these indices of neural activity.

Imaging the brain's immune response to alcohol with [11C]PBR28 TSPO Positron Emission Tomography

In humans, the negative effects of alcohol are linked to immune dysfunction in both the periphery and the brain. Yet acute effects of alcohol on the neuroimmune system and its relationships with peripheral immune function are not fully understood. To address this gap, immune response to an alcohol challenge was measured with positron emission tomography (PET) using the radiotracer [11C]PBR28, which targets the 18-kDa translocator protein, a marker sensitive to immune challenges. Participants (n = 12; 5 F; 25-45 years) who reported consuming binge levels of alcohol (>3 drinks for females; >4 drinks for males) 1-3 months before scan day were enrolled. Imaging featured a baseline [11C]PBR28 scan followed by an oral laboratory alcohol challenge over 90 min. An hour later, a second [11C]PBR28 scan was acquired. Dynamic PET data were acquired for at least 90 min with arterial blood sampling to measure the metabolite-corrected input function. [11C]PBR28 volume of distributions (VT) was estimated in the brain using multilinear analysis 1. Subjective effects, blood alcohol levels (BAL), and plasma cytokines were measured during the paradigm. Full completion of the alcohol challenge and data acquisition occurred for n = 8 (2 F) participants. Mean peak BAL was 101 ± 15 mg/dL. Alcohol significantly increased brain [11C]PBR28 VT (n = 8; F(1,49) = 34.72, p > 0.0001; Cohen's d'=0.8-1.7) throughout brain by 9-16%. Alcohol significantly altered plasma cytokines TNF-α (F(2,22) = 17.49, p < 0.0001), IL-6 (F(2,22) = 18.00, p > 0.0001), and MCP-1 (F(2,22) = 7.02, p = 0.004). Exploratory analyses identified a negative association between the subjective degree of alcohol intoxication and changes in [11C]PBR28 VT. These findings provide, to our knowledge, the first in vivo human evidence for an acute brain immune response to alcohol.

Subjective effects as predictors of substance use disorders in a clinical sample: A longitudinal study

BACKGROUND

The literature on the association between subjective effects (SEs; i.e., how an individual perceives their physiological and psychological reactions to a drug) and substance use disorders (SUDs) is largely limited to community samples. The present study addressed the following aims in a clinical sample: whether SEs predict general versus substance-specific SUD in adolescence and adulthood after controlling for conduct disorder symptoms (CDsymp); whether SEs predict SUDs across drug classes; whether SEs predict change in SUD from adolescence to adulthood; and whether there are racial/ethnic differences in associations.

METHODS

Longitudinal analyses were conducted using data from a sample of 744 clinical probands recruited from residential and outpatient SUD treatment facilities in CO during adolescence (Mage = 16.26) and re-assessed twice in adulthood (Mages = 22.56 and 28.96), approximately seven and twelve years after first assessment. SEs and CDsymp were assessed in adolescence. SUD severity was assessed at adolescence and twice during adulthood.

RESULTS

SEs assessed in adolescence robustly predicted general SUD for legal and illegal substances in adolescence and adulthood, whereas CDsymp predicted SUD primarily in adolescence. Higher positive and negative SEs in adolescence were associated with greater SUD severity after controlling for CDsymp, with similar magnitudes. Results indicated cross-substance effects of SEs on SUD. We found no evidence for racial/ethnic differences in associations.

CONCLUSIONS

We investigated the progression of SUD in a high-risk sample with greater odds of sustained SUD. In contrast to CDsymp, both positive and negative SEs consistently predicted general SUD across substances in adolescence and adulthood.

Paternal alcohol exposure attenuates maintenance and reinstated operant responding for alcohol in the offspring of rats

BACKGROUND

The heritability of alcohol use disorder is close to 50%, yet common genetic variants account for less than 5% of risk. The missing heritability may reflect environmental exposure in the parents prior to conception. Indeed, paternal alcohol exposure has many behavioral and biological consequences for rodent offspring. We recently found that paternal alcohol exposure attenuated the acquisition of operant alcohol self-administration in offspring of rats of both sexes. Here we test whether this effect extends to other phases of operant self-administration thought to model motivation, craving, and relapse.

METHODS

Wistar male rats exposed to alcohol vapors or air for 6 weeks were mated with alcohol-naïve females 8 weeks later. The adult offspring were trained to lever press for alcohol and tested under several conditions: (1) maintenance responding under a progressive ratio schedule, (2) extinction responding due to removal of the alcohol delivery contingency, (3) reinstatement of extinguished responding in the presence of alcohol-associated cues, and (4) reinitiation of lever press responding for alcohol delivery under fixed and progressive ratio schedules.

RESULTS

Alcohol-sired offspring showed reduced responding under the progressive ratio schedule and blunted cue-induced reinstatement of extinguished responding. Alcohol-sired offspring also emitted fewer responses during extinction sessions and did not reinitiate responding to the same extent as control-sired rats after alcohol delivery was restored.

CONCLUSIONS

Across all conditions, paternal alcohol exposure led to a reduction in the reinforcing effects of alcohol in offspring. These results are consistent with studies conducted with paternal cocaine exposure except that here we find effects in rats of both sexes.

A translational rodent model of individual differences in sensitivity to the aversive properties of ethanol

Background

A strong relationship exists between individual sensitivity to the aversive properties of ethanol and risk for alcohol use disorder (AUD). Despite this, our understanding of the neurobiological mechanisms underlying subjective response to ethanol is relatively poor. A major contributor to this is the absence of preclinical models that enable exploration of this individual variability similar to studies performed in humans.

Methods

Adult male and female Long-Evans rats were trained to associate a novel tastant (saccharin) with acute exposure to either saline or ethanol (1.5 g/kg or 2.0 g/kg i.p.) over three conditioning days using a standard conditioned taste aversion (CTA) procedure. Variability in sensitivity to ethanol-induced CTA was phenotypically characterized using a median split across the populations studied.

Results

When examining group averages, both male and female rats that had saccharin paired with either dose of ethanol exhibited reduced saccharin intake relative to saline controls of ethanol-induced CTA. Examination of individual data revealed a bimodal distribution of responses uncovering two distinct phenotypes present in both sexes. CTA-sensitive rats exhibited a rapid and progressive reduction in saccharin intake with each successive ethanol pairing. In contrast, saccharin intake was unchanged or maintained after an initial decrease from baseline levels in CTA-resistant rats. While CTA magnitude was similar between male and female CTA-sensitive rats, CTA-resistant females were more resistant to the development of ethanol-induced CTA than their male counterparts. Phenotypic differences were not driven by differences in baseline saccharin intake. CTA sensitivity correlated with behavioral signs of intoxication in only a subset of rats.

Conclusions

These data parallel work in humans by revealing individual differences in sensitivity to the aversive properties of ethanol that emerge immediately after initial exposure to ethanol in both sexes. This model can be leveraged in future studies to investigate the neurobiological mechanisms that confer risk for AUD.

Self-report assessment of alcohol sensitivity: An examination of the effects of different probes

OBJECTIVE

Level of response (LOR) to alcohol is associated with several alcohol-related risk factors and outcomes. However, existing self-report measures of LOR have important limitations. For example, the Self-Rating of the Effects of Alcohol Scale assesses a limited range of alcohol-related effects. Although the Alcohol Sensitivity Questionnaire (ASQ) samples a broader range of effects, it uses different probes across effects, confounding type of effect with method variation associated with the use of different probes. Focusing on the ASQ, we systematically evaluate variation in estimated LOR as a function of how number of drinks to achieve an effect is probed. Our approach addresses a major limitation of existing LOR measures which fail to account for sensitivity variability across drinking occasions.

METHOD

This study randomized 732 adult drinkers into one of four versions of the ASQ that assessed sensitivity to 15 alcohol-related effects, systematically varying the follow-up probes.

RESULTS

Accounting for (a) the minimum number of drinks consumed before feeling an effect and (b) the maximum number of drinks consumed without feeling an effect for all effects is superior to the original ASQ approach in predicting relevant outcomes.

CONCLUSIONS

Assessments of sensitivity should probe for minimum and maximum number of drinks across each of the effects. If impractical to probe for both, consistently probing for maximum number of drinks is desirable. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Subjective response to alcohol in young adults with bipolar disorder and recent alcohol use: a within-subject randomized placebo-controlled alcohol administration study

Limited data exists on mechanisms contributing to elevated risk for alcohol use disorder (AUD) in bipolar disorder. Variation in subjective response to alcohol may relate to alcohol use and risk for AUD. This study used a randomized, placebo-controlled, cross-over, within-subjects design to investigate differences in subjective response to alcohol in 50 euthymic young adults (n = 24 with and n = 26 without bipolar disorder type I). Eighty-three percent of participants with bipolar disorder were medicated. Participants completed assessments of clinical history, alcohol expectancies, and recent alcohol use. Participants were dosed to a .08 g% breath alcohol concentration. The placebo condition occurred on a separate counter-balanced day. Subjective response to alcohol was investigated at similar time points during both conditions. Group, condition, and group-by-condition interactions were modeled, with condition and time of subjective response assessment as repeated within-subject variables, and subjective response to alcohol as the dependent variable. Greater stimulating effects and liking of alcohol were reported in people with bipolar disorder (group-by-condition interactions, p < .05) than healthy young adults. While young adults with bipolar disorder reported anticipating feeling less "mellow/relaxed" when drinking (p = .02), during both beverage conditions they reported feeling more "mellow/relaxed" (main effect of group, p = .006). Feeling more "mellow/relaxed" during the alcohol condition related to greater recent alcohol use in bipolar disorder (p = .001). Exploratory analyses suggested anticonvulsants and sedatives/antihistamines may relate to differences in subjective response to alcohol in bipolar disorder. Results suggest young adults with bipolar disorder may differ in alcohol expectancies and experience alcohol intoxication differently-with distinct relations between subjective response to alcohol and alcohol use-compared to healthy young adults.

Intoxicating effects of alcohol depend on acid-sensing ion channels

Persons at risk for developing alcohol use disorder (AUD) differ in their sensitivity to acute alcohol intoxication. Alcohol effects are complex and thought to depend on multiple mechanisms. Here, we explored whether acid-sensing ion channels (ASICs) might play a role. We tested ASIC function in transfected CHO cells and amygdala principal neurons, and found alcohol potentiated currents mediated by ASIC1A homomeric channels, but not ASIC1A/2 A heteromeric channels. Supporting a role for ASIC1A in the intoxicating effects of alcohol in vivo, we observed marked alcohol-induced changes on local field potentials in basolateral amygdala, which differed significantly in Asic1a-/- mice, particularly in the gamma, delta, and theta frequency ranges. Altered electrophysiological responses to alcohol in mice lacking ASIC1A, were accompanied by changes in multiple behavioral measures. Alcohol administration during amygdala-dependent fear conditioning dramatically diminished context and cue-evoked memory on subsequent days after the alcohol had cleared. There was a significant alcohol by genotype interaction. Context- and cue-evoked memory were notably worse in Asic1a-/- mice. We further examined acute stimulating and sedating effects of alcohol on locomotor activity, loss of righting reflex, and in an acute intoxication severity scale. We found loss of ASIC1A increased the stimulating effects of alcohol and reduced the sedating effects compared to wild-type mice, despite similar blood alcohol levels. Together these observations suggest a novel role for ASIC1A in the acute intoxicating effects of alcohol in mice. They further suggest that ASICs might contribute to intoxicating effects of alcohol and AUD in humans.

Drinking context, alcohol use, and subjective responses during binge drinking episodes measured by high-resolution ecological momentary assessment (HR-EMA)

OBJECTIVE

Subjective responses to alcohol play a key role in the development and maintenance of risky drinking and alcohol use disorder (AUD). The social and environmental context where drinking occurs may moderate alcohol's subjective effects, but ecologically valid studies of these associations are limited. The present study used high-resolution ecological momentary assessment (HR-EMA) targeting real-world binge drinking episodes to examine associations among drinking context, alcohol consumption, and subjective responses to alcohol.

METHOD

Young adult heavy drinkers (N = 61; 57% male) completed two smartphone-based, 3-hr HR-EMA of drinking context (social context and location), alcohol use, and subjective responses (alcohol stimulation, sedation, feeling, liking, and wanting more). Analyses examined the associations between drinking context and subjective alcohol responses, accounting for demographic characteristics and individual differences in alcohol consumption.

RESULTS

Most (85%) participants reported binge drinking during real-world drinking events. Estimated blood alcohol concentration (eBAC) and alcohol stimulation and reward (liking, wanting) were greater when participants drank with others (vs. alone) and in a bar/restaurant (vs. other location). Sedation was higher when drinking alone versus with others.

CONCLUSIONS

The present study extends prior laboratory-based research and shows that subjective responses during naturalistic binge drinking episodes may be influenced by drinking context. Drinking with others and in bars and restaurants may increase alcohol consumption, enhance alcohol's rewarding effects, and lead to more alcohol-related harm in at-risk drinkers. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

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).

Alcohol craving in the natural environment: Moderating roles of cue exposure, drinking, and alcohol sensitivity

Effects of cue exposure and alcohol consumption (e.g., priming doses) on craving for alcohol have been examined in largely separate literature, limiting what is known about their potential interaction. Individuals with low alcohol sensitivity, a known risk factor for alcohol use disorder (AUD), exhibit stronger cue-elicited craving than their higher-sensitivity (HS) peers in both laboratory and real-world contexts. Here, underage drinkers (N = 155) completed a 21-day ecological momentary assessment (EMA) protocol in which they recorded exposure to alcohol cues and levels of craving during both nondrinking and postdrinking moments. Multilevel modeling detected a significant interaction of cue exposure and postdrinking status on craving. Cue-induced craving was increased in postdrinking moments compared to nondrinking moments. Contrary to prediction, cue-elicited increase in craving during nondrinking moments was stronger in participants reporting higher sensitivity to alcohol. In the presence of cues, lower sensitivity was robustly related to craving intensity in the postdrinking state but unrelated to craving during nondrinking moments. Craving during drinking episodes in the natural environment is magnified by the presence of alcohol cues, potentially contributing to the maintenance or acceleration of drinking episodes. Moreover, lower-sensitivity drinkers may be particularly susceptible to the combined effects of cue exposure and postdrinking status on alcohol craving. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

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.

Paternal alcohol exposure has task- and sex-dependent behavioral effect in offspring

BACKGROUND

Endophenotypes for alcohol use disorder are well known and may reflect paternal exposure effects passed down to offspring via epigenetic mechanisms. Previously, we showed that paternal alcohol exposure prior to conception attenuates the acquisition of operant alcohol self-administration. We now test whether paternal alcohol exposure alters their offsprings' behavioral responses to alcohol (endophenotypes) and global DNA methylation levels in reward-related brain regions.

METHODS

Adult male rats were exposed to alcohol vapors or air for 6 weeks and mated with alcohol-naïve females 8 weeks later. Adult male and female offspring of the alcohol- and control-sired litters were tested on three behaviors 30 m after gavage with water or alcohol (1.5 g/kg): open field, elevated plus maze, and accelerating rotarod. Global DNA methylation levels in sperm, nucleus accumbens, and prefrontal cortex were examined in male sires and in another group of offspring.

RESULTS

Alcohol-sired males showed less anxiety-like behavior in the elevated plus maze that was not affected by alcohol administration. By contrast, alcohol had anxiolytic effects in the open field in male offspring only with no paternal alcohol effect. Neither paternal alcohol exposure nor alcohol administration altered locomotor activity in either sex. Sex-specific effects of paternal alcohol exposure were seen in the rotarod test. Alcohol-sired male offspring showed blunted sensitivity to the alcohol's motor-impairing effects, whereas alcohol-sired female offspring showed enhanced sensitivity. Global DNA methylation was altered in the sperm of alcohol-exposed males, but no changes were seen in their offspring.

CONCLUSIONS

Paternal alcohol exposure prior to conception has sex- and task-dependent effects on unconditioned behaviors in their offspring.

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.

A social contextual review of the effects of alcohol on emotion

Drinking and drinking problems are complex phenomena. Understanding the etiology of alcohol use disorder requires consideration of biological, psychological, and social processes. It is our view that the last of these dimensions is just beginning to receive adequate scrutiny. In this selective review, we discuss the concept of a biopsychosocial analysis of the effects of alcohol. After briefly addressing biological and psychological research on alcohol's emotional effects, we bid to make a case for the vital role that social processes play in understanding why people drink. The bulk of the paper describes research illustrating the contributions that a social psychological perspective can make to advance understanding of the rewarding effects of alcohol. Overall, studies incorporating social contexts have revealed reliable evidence that alcohol enhances emotional experience in many social environments and have identified socio-contextual variables that moderate responses to alcohol. Further, these studies have broadened the scope of constructs thought to be socially rewarding, including social bonding, relationship functioning, and humor enjoyment. Our analysis concludes by identifying research areas we believe would profit from additional research.

Haven't lost the positive feeling: a dose-response, oral alcohol challenge study in drinkers with alcohol use disorder

Models of addiction are based on neurobiological, behavioral, and pharmacological studies in animals, but translational support from human studies is limited. Studies are lacking in examining acute responses to alcohol in drinkers with alcohol use disorder (AUD), particularly in terms of relevant intoxicating doses and measurement of stimulating and rewarding effects throughout the breath alcohol concentration (BrAC) time curve. Participants were N = 60 AUD drinkers enrolled in the Chicago Social Drinking Project and examined in three random-order and blinded sessions for subjective and physiological responses to a beverage containing 0.0 g/kg, 0.8 g/kg, and 1.2 g/kg alcohol. BrAC in the alcohol sessions at 60 min was 0.09 g/dL and 0.13 g/dL, respectively. Both doses of alcohol produced significant biphasic effects on subjective measures of stimulation, euphoria, reward (liking and wanting), sedation, and neuroendocrine and cardiovascular factors. Increased pleasurable effects of alcohol were pronounced during the rising limb-to-peak BrAC and sedating effects emerged during the declining limb. Alcohol dose-dependently increased feel drug ratings and rewarding effects at peak BrAC or early declining limb, and physiological responses at the rising limb. Thus, rather than the notion of an overall tolerance, results show an alcohol response phenotype characterized by sensitivity to alcohol's stimulating, rewarding and physiological effects. The results of this study may aid in the conceptualization of alcohol addiction as a disorder characterized by the persistence of enhanced hedonic alcohol responses rather than chronic tolerance and reward deficiency.

A critical review of front-loading: A maladaptive drinking pattern driven by alcohol's rewarding effects

Front-loading is a drinking pattern in which alcohol intake is skewed toward the onset of reward access. This phenomenon has been reported across several different alcohol self-administration protocols in a wide variety of species, including humans. The hypothesis of the current review is that front-loading emerges in response to the rewarding effects of alcohol and can be used to measure the motivation to consume alcohol. Alternative or additional hypotheses that we consider and contrast with the main hypothesis are that: (1) front-loading is directed at overcoming behavioral and/or metabolic tolerance and (2) front-loading is driven by negative reinforcement. Evidence for each of these explanations is reviewed. We also consider how front-loading has been evaluated statistically in previous research and make recommendations for defining this intake pattern in future studies. Because front-loading may predict long-term maladaptive alcohol drinking patterns leading to the development of alcohol use disorder (AUD), several future directions are proposed to elucidate the relationship between front-loading and AUD.

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).

Acute alcohol rewarding effects as a risk factor for hangover frequency

BACKGROUND/PURPOSE

Acute subjective alcohol effects appear to play an important role in predicting alcohol hangover. However, no studies have used a laboratory-based alcohol challenge to examine the concurrent or longitudinal effects of subjective alcohol responses on hangover frequency. As such, we investigated the direct and indirect effects of alcohol stimulation, sedation, liking and wanting, as measured in a controlled setting, on hangover frequency over five years.

METHOD

Participants were 294 young adult light-to-heavy social drinkers (aged 21-35 years, 42% female) enrolled in the Chicago Social Drinking Project. The study utilized a placebo-controlled, double blind, laboratory alcohol challenge and a battery of measures including the Biphasic Alcohol Effects Scale, Drug Effects Questionnaire, Hangover Symptom Scale, and alcohol use Quantity-Frequency Interview, with the latter two re-administered after five years.

RESULTS

Through the use of a path analysis, the present study found significant direct effects from alcohol liking to hangover frequency at initial testing. In addition, there were multiple significant indirect effects from greater alcohol liking and wanting to greater alcohol use quantity-frequency and, in turn, greater hangover frequency at initial testing and 5-year follow-up. Last, there were significant indirect effects from greater alcohol sedation to less alcohol use quantity-frequency and, in turn, less hangover frequency at initial testing and 5-year follow-up.

CONCLUSION

This study highlights the role of the hedonic reward and motivational salience of alcohol as potential mechanisms of alcohol-related consequences (i.e., hangover) among light-to-heavy social drinking young adults.

Within- and between-person effects of naltrexone on the subjective response to alcohol and craving: A daily diary investigation

OBJECTIVE

Naltrexone is an effective treatment for heavy drinking among young adults. Laboratory-based studies have shown that naltrexone dampens the subjective response to alcohol and craving. However, few studies have tested naltrexone's dynamic, within-person effects on subjective response and craving among young adults in natural drinking environments.

METHODS

Using daily diary data from a randomized, placebo-controlled study of naltrexone's efficacy in young adults, we examined the between-person effects of treatment condition (i.e., naltrexone vs. placebo) and medication dosage (i.e., daily, targeted, and daily + targeted) on the subjective response to alcohol and craving on drinking days. Multilevel mediation models predicted subjective response and craving from treatment condition (between-person) and medication dosage (within-person), accounting for drinking levels. All effects were disaggregated within and between persons.

RESULTS

At the between-person level, naltrexone directly blunted intense subjective effects (i.e., "impaired", "drunk") and indirectly blunted subjective effects through reduced drinking. Naltrexone was not associated with craving. Between-person effects were not significant after alpha correction, but their effect sizes (bs = 0.14 to 0.17) exceeded the smallest effect size of interest. At the within-person level, taking two (vs. 1) pills was associated with heavier drinking, and taking one (vs. 0) pill was associated with lighter drinking, and lighter drinking was associated with a lower subjective response and craving. Treatment condition did not moderate the within-person effects of dosing on outcomes.

CONCLUSIONS

Our findings suggest that the direct between-person effect of naltrexone was largest on intense subjective responses, blunting feelings of being "drunk" and "impaired". Future research using momentary (rather than daily) assessments could confirm and extend these findings.

Moderators of subjective response to alcohol in the human laboratory

BACKGROUND

Subjective response (SR) to alcohol represents a biobehavioral risk factor for heavy drinking and for developing alcohol use disorder (AUD). Identifying moderators of SR have been hindered by small sample sizes that are often used in alcohol administration studies.

METHODS

This study combined data from multiple alcohol administration trials to test whether sex, family history of alcohol problems, and impulsivity (via delay discounting) predict SR to alcohol, comprised of four domains: stimulation, sedation, negative affect, and craving. Non-treatment-seeking heavy drinkers (N = 250) completed a battery of self-report scales and behavioral measures of alcohol use and problems, mood, and impulsivity. All participants completed an intravenous alcohol administration session wherein SR domains were measured at baseline, 20, 40, and 60 mg%.

RESULTS

Analyses using multilevel modeling showed that male sex independently predicted higher alcohol-induced stimulation and alcohol craving, after controlling for other moderators. A family history of alcohol problems also independently predicted alcohol craving after controlling for other moderators.

CONCLUSIONS

Using a large sample and advanced data analytic methods, this study extends the literature on alcohol administration by identifying important moderators of SR in heavy drinkers: namely, male sex and family history of alcohol problems. These findings consolidate and extend a growing body of research aimed at differentiating individuals most likely to report the SR features that confer risk for AUD.

Subjective and Cardiovascular Responses to an Acute Laboratory Gambling Task in Men and Women

Men have previously been overrepresented in gambling for money but in recent years there has been an increase in recognition that women who gamble are "catching up" with their male counterparts. There have been few experimental studies investigating the subjective effects of gambling, and even less have explored the gender differences. As gender differences previously have been reported in the subjective effects of several drugs of abuse such as opioids, amphetamines and alcohol, we sought to investigate if the subjective effects of gambling also differed by gender. The present article analyzes if gender modulates the subjective and physiological effects of an acute laboratory gambling task in healthy men and women. Eighty-two men and women (n = 35 men, n = 47 women) were tested with an online slot machine gambling session and self-report questionnaires of mood and blood pressure were taken before and after gambling. Both men and women showed stimulatory effects of gambling i.e., feelings of high and euphoria and but no differences were found between genders. Findings suggest that both men and women equally experience a pattern of stimulatory effects of gambling from the gambling situation. Gambling therefore seems to have the same abuse potential in both men and women. Although the gap between men and women is narrowing, immediate subjective and physiologic responses do not explain gender differences in the epidemiology of pathological gambling. The contexts and factors that foster or hinder the evolution of gambling addiction in males and females should be further explored. This conclusion is interesting in light of that men are over three times more at risk to experience gambling related problems than women and this risk may depend on other factors involved in the development of addiction.

Low versus high level of response to alcohol affects amygdala functional connectivity during processing of emotional stimuli

BACKGROUND

Low levels of response (low LR) to alcohol predict heavy drinking and alcohol problems. Functional magnetic resonance imaging (fMRI) studies of emotion processing have shown that low LR individuals exhibit lower activation in task-related brain regions following both placebo and alcohol administration, but these studies did not examine functional brain networks that might contribute to the phenomena. The current study expands upon the earlier results by evaluating whether functional connectivity differences between the amygdala and other brain regions modulated by emotional face processing are associated with LR. Based on prior findings, we hypothesized that low LR is related to lower functional connectivity in fronto-amygdalar functional circuits, which underlie the processing of emotional stimuli.

METHODS

Secondary analyses were conducted on data from a double-blind, placebo-controlled, within-subjects, cross-over study in 108 18-to-25-year-old low and high LR sex-matched pairs without alcohol use disorder at baseline. Participants performed modified emotional faces processing tasks after receiving placebo or approximately 0.7 ml/kg of ethanol. Psychophysiological interaction analyses examined functional connectivity between left and right amygdalae and related brain circuits using LR-by-alcohol general linear models. The data included 54 sex-matched pairs with 216 fMRI scans comprising alcohol and placebo conditions.

RESULTS

Compared with individuals with high LR, low LR subjects demonstrated lower functional connectivity between the amygdala and the frontal lobes, insula, and parietal regions, while processing angry and happy faces. Interactions showed lower connectivity following alcohol in low LR and higher connectivity in high LR groups.

CONCLUSIONS

Low LR individuals demonstrated lower functional connectivity in response both to placebo and a modest dose of ethanol. Attenuated connectivity among low LR individuals when processing emotional faces may contribute to an impaired ability to recognize alcohol intoxication in social situations and to appraise angry and happy emotions irrespective of whether alcohol is consumed.

An Overview of Appetite-Regulatory Peptides in Addiction Processes; From Bench to Bed Side

There is a substantial need for new pharmacological treatments of addiction, and appetite-regulatory peptides are implied as possible candidates. Appetite regulation is complex and involves anorexigenic hormones such as glucagon-like peptide-1 (GLP-1) and amylin, and orexigenic peptides like ghrelin and all are well-known for their effects on feeding behaviors. This overview will summarize more recent physiological aspects of these peptides, demonstrating that they modulate various aspects of addiction processes. Findings from preclinical, genetic, and experimental clinical studies exploring the association between appetite-regulatory peptides and the acute or chronic effects of addictive drugs will be introduced. Short or long-acting GLP-1 receptor agonists independently attenuate the acute rewarding properties of addictive drugs or reduce the chronic aspects of drugs. Genetic variation of the GLP-1 system is associated with alcohol use disorder. Also, the amylin pathway modulates the acute and chronic behavioral responses to addictive drugs. Ghrelin has been shown to activate reward-related behaviors. Moreover, ghrelin enhances, whereas pharmacological or genetic suppression of the ghrelin receptor attenuates the responses to various addictive drugs. Genetic studies and experimental clinical studies further support the associations between ghrelin and addiction processes. Further studies should explore the mechanisms modulating the ability of appetite-regulatory peptides to reduce addiction, and the effects of combination therapies or different diets on substance use are warranted. In summary, these studies provide evidence that appetite-regulatory peptides modulate reward and addiction processes, and deserve to be investigated as potential treatment target for addiction.

The language of subjective alcohol effects: Do young adults vary in their feelings of intoxication?

Among young adults, subjective feelings of alcohol's effects often guide risky decision making. The majority of studies measuring subjective effects have used singular indices ("How drunk do you feel?") which limits our understanding of young adults' full range of subjective states and their individual differences in subjective effects language. Toward a more in-depth understanding of the heterogeneity among alcohol users based on their subjective experiences of alcohol's effects, we identified latent classes of individuals based on their self-generated language describing feelings after drinking and compared these classes across demographic and drinking characteristics. Participants (N = 323, 54% women, 68% White, Ages 18-25 years) were recruited using Amazon's Mechanical Turk (MTurk). Participants listed words they would use to describe how they feel after drinking low, moderate, and heavy amounts of alcohol. Four latent classes of young adults emerged: "happy drinkers" (31%) primarily reported feeling "happy" when drinking; "relaxed drinkers" (24%) reported feeling happy, relaxed, and buzzed; "buzzed drinkers" (18%) reported feeling buzzed and dizzy; and "multiexperience drinkers" (27%) reported feeling buzzed, tipsy, drunk, and wasted. Relaxed drinkers indicated heavier alcohol use and buzzed drinkers reported lower drinking frequency. Classes did not differ by demographic characteristics. Young adult alcohol users can be distinguished based on the language they use to describe their feelings of intoxication. To continue to advance our understanding of subjective effects, it is necessary to take into account the full range of language used and how this language differs by young adult drinking behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cross-sectional and prospective associations of drinking characteristics with scores from the Self-Report of the Effects of Alcohol questionnaire and findings from alcohol challenges

BACKGROUND

Data from 2 generations of participants in the San Diego Prospective Study (SDPS) were used to compare cross-sectional and prospective relationships of 5 measures of the low level of response (low LR) to alcohol to 2 key alcohol-related outcomes.

METHODS

The analyses used data from 373 SDPS male probands and 158 male and female offspring of these individuals to evaluate relationships of 5 LR measures to the prior 5-year maximum drinks per occasion and the number of 11 DSM-IV alcohol use disorder (AUD) criteria experienced. Probands' LR measures included responses to alcohol challenges administered 15 years previously, and ratings for both generations included measures of the number of standard drinks during four periods: the first five times of drinking (SRE-5), the prior three drinking months (SRE-3), the period of heaviest drinking (SRE-H), and a total average across all time frames (SRE-T). Analyses included zero-order correlations, correlations using covariates, and hierarchical multiple regression analyses.

RESULTS

All 5 LR measures were correlated with aspects of maximum drinks and the number of AUD criteria, but the most robust results were seen for SRE-3 and maximum drinks. Correlations were less consistent for SRE-5, a measure more closely related to outcomes in the offspring. Hierarchical regression analyses supported most of these conclusions and showed that alcohol challenge-based LRs added significant information regarding maximum drinks even when evaluated with SRE values. The close correlation between SRE-H and SRE-T argues against the need for studies to include both measures. The patterns of results were similar irrespective of whether covariates were included.

CONCLUSIONS

There were significant correlations of maximum drinks and the number of AUD criteria with findings from prior alcohol challenges and all SRE scores. Challenges and SRE reports are related but not identical LR measures. All SRE scores, including SRE-5, offered useful information regarding subsequent drinking behavior.

Transfer of incentive salience from a first-order alcohol cue to a novel second-order alcohol cue among individuals at risk for alcohol use disorder: electrophysiological evidence

BACKGROUND AND AIMS

In susceptible individuals, cues associated with drug use are theorized to take on incentive-motivational properties, including the ability to reinforce higher-order, drug-related associative learning. This study aimed to test this prediction among people varying in risk for alcohol use disorder.

DESIGN, SETTING AND PARTICIPANTS

Repeated-measures experiment with a measured individual difference variable at a University psychology laboratory in Missouri, USA. One hundred and six young adults (96 contributed complete data) were pre-selected to represent the upper and lower quartiles of self-reported sensitivity to alcohol's acute effects.

MEASUREMENTS

Participants completed a second-order Pavlovian conditioning paradigm in which an initially neutral visual cue (second-order conditional stimulus; CS2 ) predicted onset of an olfactory cue (first-order conditional stimulus; CS1 ). Olfactory cues were isolated from alcoholic beverages, sweets and non-comestible substances, each presumed to have a natural history of first-order conditioning. Event-related potential responses to the CS2 across its conditioning and extinction, and to the CS1 , provided neurophysiological indices of incentive salience (IS).

FINDINGS

The IS of the alcohol CS1 was higher among participants low in alcohol sensitivity (LS), relative to their higher-sensitivity (HS) peers. The IS of the CS2 paired with the alcohol CS1 increased across the CS2 conditioning phase among LS but not HS participants. Also, LS (but not HS) individuals also experienced increases in alcohol craving following alcohol CS1 exposure, and this change was correlated with increases in the IS of the CS2 paired with the alcohol CS1 .

CONCLUSIONS

Alcoholic beverage odor, a proximal cue for alcohol consumption, appears to reinforce conditioning of neurophysiological responses to a novel cue among low alcohol sensitivity (LS) individuals but not high alcohol sensitivity individuals, providing the first evidence that the LS phenotype may be associated with differences in the conditioned reinforcing properties of alcohol-related cues. These findings support the idea that the LS phenotype may increase alcohol use disorder risk via susceptibility to incentive salience sensitization.

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.

Relationship between level of response to alcohol and acute tolerance

BACKGROUND

A low level of response (low LR) to alcohol correlates with the later development of alcohol-related problems. Although some of the underpinnings of LR are understood, little is known about the potential relationship between LR and acute tolerance. The current analyses tested the hypothesis that a low LR will be explained in part by more intense acute tolerance to alcohol during a drinking session.

METHODS

Data were generated through a reanalysis of data from 120 individuals who were 18- to 25-year-old, sex-matched pairs of low and high LR drinkers who at baseline did not meet criteria for an alcohol use disorder. Each subject participated in an oral alcohol challenge in which they consumed about 0.7 ml ethanol per kg and acute tolerance was measured as the differences in alcohol's effects at similar breath alcohol levels (BrACs) during the rising and falling breath alcohol concentration (BrAC) curve. Measures included aspects of the Subjective High Assessment Scale (SHAS) and body sway.

RESULTS

Contrary to our hypothesis, but similar to results with other alcohol measures, acute tolerance was significantly attenuated in low LR compared with high LR individuals on most SHAS scores. Neither LR group demonstrated acute tolerance to alcohol for sleepiness or body sway. Men and women did not differ on any of these measures.

CONCLUSION

These data do not support a role of acute tolerance in the low LR to alcohol as measured by subjective feelings of intoxication or body sway in these subjects, findings that were similar across males and females. In addition, consistent with the literature, the analyses demonstrated differences across measures such that acute tolerance was observed for most measures of subjective effects but not for body sway. Among the subjective effects, acute tolerance was observed for alcohol's intoxicating effect but not for feeling sleepy.

Neural correlates of inhibitory control are associated with stimulant-like effects of alcohol

Poor inhibitory control and heightened feelings of stimulation after alcohol are two well-established risk factors for alcohol use disorder (AUD). Although these risk factors have traditionally been viewed as orthogonal, recent evidence suggests that the two are related and may share common neurobiological mechanisms. Here we examined the degree to which neural activity during inhibition was associated with subjective reports of stimulation following alcohol. To assess neural changes during inhibition, moderate alcohol drinkers performed a stop signal task during fMRI without drug. To assess subjective responses to alcohol they ingested alcohol (0.8 g/kg) or placebo beverages under double-blind conditions and provided subjective reports of stimulation and sedation. Feelings of stimulation following alcohol were inversely associated with activity in the supplementary motor area, insula, and middle frontal gyrus during inhibition (successful stop trials compared to go trials). Feelings of sedation did not correlate with brain activation. These results extend previous findings suggesting that poor inhibitory control is associated with more positive subjective responses to alcohol. These interrelated risk factors may contribute to susceptibility to future excessive alcohol use, and ultimately lead to neurobiological targets to prevent or treat AUD.

The foraging gene affects alcohol sensitivity, metabolism and memory in Drosophila

The genetic basis of alcohol use disorder (AUD) is complex. Understanding how natural genetic variation contributes to alcohol phenotypes can help us identify and understand the genetic basis of AUD. Recently, a single nucleotide polymorphism in the human foraging (for) gene ortholog, Protein Kinase cGMP-Dependent 1 (PRKG1), was found to be associated with stress-induced risk for alcohol abuse. However, the mechanistic role that PRKG1 plays in AUD is not well understood. We use natural variation in the Drosophila for gene to describe how variation of cGMP-dependent protein kinase (PKG) activity modifies ethanol-induced phenotypes. We found that variation in for affects ethanol-induced increases in locomotion and memory of the appetitive properties of ethanol intoxication. Further, these differences may stem from the ability to metabolize ethanol. Together, this data suggests that natural variation in PKG modulates cue reactivity for alcohol, and thus could influence alcohol cravings by differentially modulating metabolic and behavioral sensitivities to alcohol.

Subjective Responses to Alcohol in the Development and Maintenance of Alcohol Use Disorder

OBJECTIVE

Alcohol use disorder (AUD) remains an urgent public health problem. Longitudinal data are needed to clarify the role of acute subjective responses to alcohol in the development and maintenance of excessive drinking and AUD. The authors report on 10 years of repeated examination of acute alcohol responses in the Chicago Social Drinking Project.

METHODS

Young adult drinkers (N=190) participated in an initial alcohol challenge (0.8 g/kg of alcohol compared with placebo) that was repeated 5 and 10 years later. They were also assessed on drinking behavior and AUD symptoms at numerous intervals across the decade. Retention was high, as 184 of the 185 (99%) nondeceased active participants completed the 10-year follow-up, and 91% (163 of 179) of those eligible for alcohol consumption engaged in repeated laboratory testing during this interval.

RESULTS

At the end of the decade, 21% of participants met criteria for past-year AUD. Individuals who reported the greatest alcohol stimulation, liking, and wanting at the initial alcohol challenge were most likely to have developed AUD 10 years later. Further, alcohol-induced stimulation and wanting increased in reexamination testing among those with the highest AUD symptoms as the decade progressed.

CONCLUSIONS

Initial stimulant and rewarding effects of alcohol predicted heavy alcohol use, and the magnitude of these positive subjective effects increased over a 10-year period in those who developed AUD compared with those who did not develop the disorder. The findings demonstrate systematic changes in subjective responses to alcohol over time, providing an empirical basis for prevention, early intervention, and treatment strategies.

Drinking Intensity at Age 29/30 as a Predictor of Alcohol Use Disorder Symptoms at Age 35 in a National Sample

OBJECTIVE

The purpose of this longitudinal study was to identify associations of drinking intensity at age 29/30 with symptoms of alcohol use disorder (AUD) at age 35.

METHOD

Analyses used national longitudinal data from 1,253 individuals (53.5% female) participating in the Monitoring the Future study. Age 29/30 data were collected from 2005 to 2013; age 35 data were collected from 2010 to 2018. Multivariable models regressed age 35 past-5-year AUD symptoms (vs. nondisordered drinking/abstinence) on age 29/30 past-2-week drinking intensity (no/low [0-4] drinking, binge [5-9] drinking, high-intensity [10+] drinking), with key covariates being controlled for.

RESULTS

At age 35, 32.6% (SE = 1.50) of respondents reported AUD symptoms. AUD symptoms at age 35 were reported by 77.5% (SE = 4.79) of participants who reported age 29/30 high-intensity drinking and 60.6% (SE = 3.95) of participants who reported age 29/30 binge drinking. Age 35 past-5-year abstinence was reported by almost no respondents reporting age 29/30 binge drinking or high-intensity drinking. AUD symptoms at age 35 were significantly more likely for those who reported binge (adjusted multivariable odds ratio [AOR] = 5.61, 95% CI [3.79, 8.30], p < .001) or high-intensity (AOR = 12.26, 95% CI [6.70, 22.41], p < .001) drinking versus no/low drinking at age 29/30. The likelihood of having AUD symptoms was significantly higher for high-intensity than for binge drinkers (AOR = 2.18, 95% CI [1.14, 4.19], p = .019).

CONCLUSIONS

Nearly 80% of those young adults who reported engaging in high-intensity drinking (10+ drinks in a row) at age 29/30 later reported AUD symptoms at age 35. High-intensity drinking appears to be a strong prospective marker of risk for AUD symptoms among adults in the United States.

Drinking Intensity at Age 29/30 as a Predictor of Alcohol Use Disorder Symptoms at Age 35 in a National Sample

OBJECTIVE

The purpose of this longitudinal study was to identify associations of drinking intensity at age 29/30 with symptoms of alcohol use disorder (AUD) at age 35.

METHOD

Analyses used national longitudinal data from 1,253 individuals (53.5% female) participating in the Monitoring the Future study. Age 29/30 data were collected from 2005 to 2013; age 35 data were collected from 2010 to 2018. Multivariable models regressed age 35 past-5-year AUD symptoms (vs. nondisordered drinking/abstinence) on age 29/30 past-2-week drinking intensity (no/low [0-4] drinking, binge [5-9] drinking, high-intensity [10+] drinking), with key covariates being controlled for.

RESULTS

At age 35, 32.6% (SE = 1.50) of respondents reported AUD symptoms. AUD symptoms at age 35 were reported by 77.5% (SE = 4.79) of participants who reported age 29/30 high-intensity drinking and 60.6% (SE = 3.95) of participants who reported age 29/30 binge drinking. Age 35 past-5-year abstinence was reported by almost no respondents reporting age 29/30 binge drinking or high-intensity drinking. AUD symptoms at age 35 were significantly more likely for those who reported binge (adjusted multivariable odds ratio [AOR] = 5.61, 95% CI [3.79, 8.30], p < .001) or high-intensity (AOR = 12.26, 95% CI [6.70, 22.41], p < .001) drinking versus no/low drinking at age 29/30. The likelihood of having AUD symptoms was significantly higher for high-intensity than for binge drinkers (AOR = 2.18, 95% CI [1.14, 4.19], p = .019).

CONCLUSIONS

Nearly 80% of those young adults who reported engaging in high-intensity drinking (10+ drinks in a row) at age 29/30 later reported AUD symptoms at age 35. High-intensity drinking appears to be a strong prospective marker of risk for AUD symptoms among adults in the United States.

Alcohol subjective responses in heavy drinkers: Measuring acute effects in the natural environment versus the controlled laboratory setting

BACKGROUND

For decades, laboratory alcohol challenges have been the "gold standard" for measuring individual differences in alcohol's subjective effects. However, these approaches are expensive and labor-intensive, making them impractical for large-scale use. This study examined the reliability and validity of a new high-resolution EMA (HR-EMA) ambulatory approach to assessing alcohol use and subjective responses in drinkers' natural environments.

METHODS

Participants were 83 young adult heavy social drinkers (58% male; mean ± SD age = 25.4 ± 2.6 years) who completed up to two smartphone-based, 3-h HR-EMA assessments of alcohol use and related subjective responses in their typical drinking environments. Reported alcohol consumption during the HR-EMA periods was used to calculate estimated blood alcohol concentration (eBAC). Subjective effects were measured using the Brief Biphasic Alcohol Effects Scale (B-BAES) and Drug Effects Questionnaire (DEQ). All participants also completed identical measures during a separate, 4 to 5-h laboratory session in which they received a 0.8 g/kg alcohol challenge.

RESULTS

Most natural environment drinking episodes (87%) met or exceeded the threshold for binge drinking (final mean eBAC = 0.12 g/dl). Associations between reported alcohol use and subjective responses on the B-BAES and DEQ were strongest earlier in the drinking events, with fair reliability of reported subjective effects across two HR-EMA episodes (intraclass correlation [ICC] range = 0.46-0.49). There was fair-to-good correspondence between HR-EMA- and laboratory-derived subjective responses (ICC range = 0.49-0.74), even after accounting for differences in alcohol consumption and drinking context. Reported stimulating and rewarding alcohol effects were higher in the ambulatory than laboratory setting, and vice versa for sedating effects.

CONCLUSIONS

This study supports the reliability and validity of smartphone-based HR-EMA to measure alcohol use and subjective responses in heavy drinkers' natural environments. These findings lend support to the use of ambulatory HR-EMA as a measure of alcohol subjective responses in risky drinkers when a laboratory protocol is not practical, feasible, or safe.

Effect of Δ9-Tetrahydrocannabinol on frontostriatal resting state functional connectivity and subjective euphoric response in healthy young adults

BACKGROUND

Few studies have examined how Δ9-Tetrahydrocannabinol (THC), the main psychoactive component of cannabis, impacts brain reward circuitry in humans. In this study, we examined if an acute dose of THC altered resting state functional connectivity between the striatum and prefrontal cortex among healthy young adults with limited cannabis use.

METHODS

Participants received THC (n = 24) or placebo (n = 22) in a double-blind, randomized, between-subject design. Participants completed self-report measures of euphoria and drug-liking throughout the visit. Approximately 120 min after drug administration, participants completed an 8-min resting state functional MRI (rs-fMRI) scan. We utilized seed-based connectivity of the striatum (bilateral putamen, caudate, and NAcc seeds) to the frontal cortex.

RESULTS

Individuals who received THC demonstrated greater rs-fMRI connectivity between the right NAcc and regions of the medial prefrontal cortex (mPFC) (p-values<0.05, corrected) and higher subjective euphoria ratings (p = .03) compared to compared to individuals who received placebo. Higher ratings of euphoria were related to greater right NAcc-dorsal mPFC (dmPFC) connectivity for the THC group (p=.03), but not for the placebo group (p=.98).

CONCLUSIONS

This is one of the first studies to examine rs-fMRI connectivity in healthy young non-users after THC administration. We found individuals receiving THC show greater rs-fMRI connectivity between the NAcc and mPFC, regions implicated in reward, compared to individuals receiving placebo. In addition, individuals receiving THC reported higher subjective euphoria ratings, which were positively associated with NAcc-dmPFC connectivity. Overall, our findings suggest THC may produce subjective and neural reward responses that contribute to the rewarding, reinforcing properties of cannabis.

Effects of alcohol sensitivity on alcohol-induced blackouts and passing out: An examination of the alcohol sensitivity questionnaire among underage drinkers

BACKGROUND

The role of alcohol sensitivity in the experience of blacking out and passing out has not been well established. Here, we examined the relation between individual differences in alcohol sensitivity (i.e., numbers of drinks required to experience various effects of alcohol) and reports of blacking out and passing out in the past year.

METHODS

Participants (925 healthy, underage college student drinkers) completed the Alcohol Sensitivity Questionnaire (ASQ) and reported on their past year blacking out and passing out experiences.

RESULTS

The fit of the ASQ's 2-factor structure was fair (CFI = 0.90, RMSEA = 0.09) in this sample of underage drinkers. In unadjusted models, higher ASQ scores (i.e., requiring more drinks to experience effects, indicating lower alcohol sensitivity) were associated with experiencing more blackouts (IRR = 1.68 [1.31-2.15]) and passing out (IRR = 2.25 [1.59-3.18]) in the past year. After controlling for typical consumption, however, higher ASQ scores were associated with fewer past-year blackouts (IRR = 0.76 [0.60-0.98]). Total ASQ scores moderated the relationship between typical alcohol consumption and blackout occurrence (interaction IRR = 0.96 [0.93-0.98]), but not passing out occurrence (interaction IRR = 0.95 [0.89-1.01]), with the quantity of alcohol consumed more strongly associated with blackout occurrence among higher-sensitivity than lower-sensitivity drinkers.

CONCLUSIONS

These findings are consistent with prior work suggesting that low sensitivity may act as a paradoxical risk factor for certain heavy drinking effects, contributing to higher levels of alcohol consumption and more frequent negative consequences while also conferring protection (relative to high-sensitivity peers) at a given level of alcohol exposure.