Breath Alcohol Concentration Research Articles

Comparing associations between mood and breath alcohol concentration in the laboratory and natural environment.

Associations between mood and drinking are part of many theoretical models of problematic alcohol use. Laboratory and ecological momentary assessment (EMA) research on associations between mood and drinking behavior has produced mixed findings, and these constructs are often measured using different methods depending on research context. The present study compares associations between mood and alcohol consumption across research contexts (laboratory vs. daily life) and measurement methods (breathalyzer vs. self-report). Forty-five young adults (53% women, Mage = 24.5) who drank moderate-to-heavy amounts completed an alcohol administration session and then 6 weeks of EMA with ambulatory breathalyzer samples. Participants reported their current mood (happy, nervous, upset, and excited) in both the laboratory and during EMA. Momentary, day, and person-level mood variables were examined in multilevel models predicting objective alcohol consumption [breath alcohol concentration (BrAC); lab and EMA] and subjective consumption (self-reported drinking occurrence and number of drinks; EMA). We identified discrepant mood-BrAC associations across laboratory and EMA contexts. Momentary excitement was negatively associated with BrAC in the lab, but positively associated with BrAC during EMA (ps < .01). We also identified discrepancies within EMA depending on the alcohol consumption measure used (BrAC or self-reported number of drinks) and the level of analysis (momentary or day). Studies testing theoretical models involving directional mood-alcohol associations (e.g., affective reinforcement models) need to carefully consider how research context and methods may influence findings of associations between mood and drinking. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Hydrogen intake relieves alcohol consumption and hangover symptoms in healthy adults: a randomized and placebo-controlled crossover study

Alcohol-induced hangover represents a significant, yet understudied, global hazard and a large socioeconomic burden. The aim of this study was to investigate the effects of hydrogen on relieving drinking and hangover symptoms in 20 healthy volunteers. In this pilot, randomized, double-blinded, placebo-controlled, matched, crossover interventional trial, participants were matched into pairs and randomly assigned. Study group 1 inhaled placebo air for 1 h, followed by drinking 100 mL liquor (40% alcohol) within 10 min, and then pure water. Study group 2 inhaled a mixture of hydrogen and oxygen gas for 1 h, followed by drinking 100 mL liquor within 10 min, and then hydrogen dissolved in water. On a second intervention day (crossover) ≥1 wk later, study-group subjects were switched to the opposite order. Breath alcohol concentration (BrAC), hangover severity, and cognitive scores were measured. The BrACs within the hydrogen group were significantly lower than those within the placebo group after 30 min, 60 min, and 90 min (P< 0.05). The hydrogen group reported having fewer hangover symptoms compared with the placebo group (placebo: 77% of symptoms absent, 19.7% of mild symptoms, 2.7% of moderate symptoms, 0.7% of severe symptoms; hydrogen: 88.6% of symptoms absent, 10% of mild symptoms, 1.3% of moderate symptoms, 0% of severe symptoms; P< 0.001). Hydrogen treatment improved cognitive testing scores (P< 0.05), including attention and executive functions. Furthermore, consumption of hydrogen was negatively (β = -13.016; 95% CI: -17.726, -8.305; P< 0.001) and female sex was positively (β = 22.611; 95% CI: 16.226, 28.997; P< 0.001) correlated with increased BrACs. Likewise, the consumption of hydrogen was negatively (OR: 0.035; 95% CI: 0.007, 0.168; P< 0.001) while female sex was positively (OR: 28.838; 95% CI: 5.961, 139.506; P< 0.001) correlated with the severity of hangover symptoms. Hydrogen decreases BrACs and relieves the symptoms of hangovers. This trial was registered at the China Clinical Trial Registry (http://www.chictr.org.cn/showproj.aspx?proj=58359) as ChiCTR2200059988.

Decision strategies while intoxicated relate to alcohol-impaired driving attitudes and intentions.

Approximately 28 million individuals engage in alcohol-impaired driving (AID) every year. This study investigated individuals' AID decision making strategies under intoxication, their variability across the breath alcohol concentration (BrAC) curve, and the association between strategy and AID attitudes, intentions, and behavior. Seventy-nine adults (mean 23.9 years, 57% female) who drank alcohol ≥2 days per week and lived >2 miles away from their typical drinking locations completed an alcohol administration protocol and AID decision making task. AID attitudes, intentions, and behaviors were assessed repeatedly across the BrAC curve. Bayesian cognitive modeling identified decision strategies used by individuals on the AID decision making task, revealing whether alcohol consumption level and/or ride service cost factored into individuals' decisions to drive while impaired or obtain a ride. Additional analyses tested whether AID attitudes and intentions were related to individuals' decision strategies. Two decision strategies were examined on the ascending and descending limbs of the BrAC curve: compensatory (both consumption level and ride service cost factored into AID decisions) and non-compensatory (only consumption level factored into AID decisions). Switching to a compensatory strategy on the descending limb was associated with lower perceived intoxication, perceiving AID as less dangerous, and being willing to drive above the legal BrAC limit. Results suggest that risk for engaging in AID is higher for those using a cost-sensitive, compensatory strategy when making AID decisions under intoxication. Future research is needed to test whether AID countermeasures (e.g., subsidized ride services) are differentially effective according to decision strategy type. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Effects of stress, alcohol prime dose, and sex on ad libitum drinking.

The Self-Medication Hypothesis (SMH) theorizes that alcohol is used to alleviate negative states. We assessed whether an acute social stressor (Trier Social Stress Test, TSST), a priming dose of alcohol, and participant sex impacted 90-min ad libitum drinking. We expected exposure to stress to be associated with increased consumption, and this effect to be stronger following an alcohol priming dose; we also explored whether participant sex moderated these effects. Using a 2×2 experimental design, we randomized groups of two to three drinkers to stress (TSST vs. no TSST) and priming beverage (alcohol vs. placebo) conditions. All participants subsequently completed the 90-min ad libitum drinking period and were instructed not to exceed more than one alcoholic beverage per hour for optimal performance to model behavioral impaired control. We examined (a) number of drinks ordered, (b) violations of the drink limit, (c) change in breath alcohol concentration (BAC), and (d) peak BAC. Analyses showed that exposure to stress was associated with heavier ad libitum drinking. This effect was qualified by a three-way interaction; women who received a stressor and no prime dose (placebo) reached higher BACs, whereas men who received a stressor and a prime reached higher BACs. The hypothesized interaction between an alcohol priming dose and social stress was only evident among men, whereas women drank more under social stress in the absence of a priming dose. Findings suggest the importance of exploring sex differences in future studies of the SMH. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Analysis on topological alterations of functional brain networks after acute alcohol intake using resting-state functional magnetic resonance imaging and graph theory.

AimsAlcohol consumption could lead to a series of health problems and social issues. In the current study, we investigated the resting-state functional brain networks of healthy volunteers before and after drinking through graph-theory analysis, aiming to ascertain the effects of acute alcohol intake on topology and information processing mode of the functional brain networks.Materials and methodsThirty-three healthy volunteers were enrolled in this experiment. Each volunteer accepted alcohol breathalyzer tests followed by resting-state magnetic resonance imaging at three time points: before drinking, 0.5 h after drinking, and 1 h after drinking. The data obtained were grouped based on scanning time into control group, 0.5-h group and 1-h group, and post-drinking data were regrouped according to breath alcohol concentration (BrAC) into relative low BrAC group (A group; 0.5-h data, n = 17; 1-h data, n = 16) and relative high BrAC group (B group; 0.5-h data, n = 16; 1-h data, n = 17). The graph-theory approach was adopted to construct whole-brain functional networks and identify the differences of network topological properties among all the groups.ResultsThe network topology of most groups was altered after drinking, with the B group presenting the most alterations. For global network measures, B group exhibited increased global efficiency, Synchronization, and decreased local efficiency, clustering coefficient, normalized clustering coefficient, characteristic path length, normalized characteristic path length, as compared to control group. Regarding nodal network measures, nodal clustering coefficient and nodal local efficiency of some nodes were lower in B group than control group. These changes suggested that the network integration ability and synchrony improved, while the segregation ability diminished.ConclusionThis study revealed the effects of acute alcohol intake on the topology and information processing mode of resting-state functional brain networks, providing new perceptions and insights into the effects of alcohol on the brain.

An Optimized Approach Using Transfer Learning to Detect Drunk Driving

Although the statistics show a slow decline in traffic accidents in many countries over the last few years, drunk or drug-influenced driving still contributes to enough shares in those records to act. Nowadays, breath analysers are used to estimate breath alcohol content (BAC) by law enforcement as a preliminary alcohol screening in many countries. Therefore, since breath analysers or field sobriety testers do not accurately measure BAC, the analysis of blood samples of individuals is required for further action. Many researchers have presented various approaches to detect drunk driving, for example, using sensors, face recognition, and a driver’s behaviour to confound the shortcomings of the time-honoured approach using breath analysers. But each one has some limitations. This study proposed a plan to distinguish between drivers’ states, that is, sober or drunk, by the use of transfer learning from the convolutional neural network (CNN) features to the random forest (RF) features with an accuracy of up to 93%, which is higher than that of existing models. With the same dataset, to validate our research, a comparative analysis was performed with other existing model classifiers such as the simple vector machine (SVM) with an accuracy of 65% and the K-nearest neighbour (KNN) with an accuracy of 62%, and it was found that our approach is an optimized approach in terms of accuracy, precision, recall, F1-score, AUC-ROC curve, and Matthew’s correlation coefficient (MCC) with confusion matrix.

The effects of oral and vaporized cannabis alone, and in combination with alcohol, on driving performance using the STISIM driving simulator: A two-part, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory protocol.

The legalization of cannabis for medicinal and non-medicinal purposes, and the corresponding increase in diversity of cannabis products, has resulted an urgent need for cannabis regulatory science. Among the most pressing needs is research related to impairment due to cannabis exposure, especially on driving performance. The present project was designed to evaluate the impact of oral and vaporized cannabis, when administered alone or in combination with alcohol, on simulated driving performance (STISIM driving simulator), cognitive/psychomotor ability, and field sobriety performance. Healthy adults will complete two, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory studies, one with oral cannabis (16 men/16 women) and the second with vaporized cannabis (16 men/16 women). In each study, participants will complete seven experimental sessions during which acute doses of placebo or high Δ9-THC cannabis containing 0, 10, or 25 mg Δ9-THC will be administered both alone and in combination with placebo or alcohol-containing beverages (target breath alcohol concentrations, BAC, of 0.0% or 0.05%). A positive control session (i.e., alcohol at target BAC of 0.08% with placebo cannabis) will also be completed. Simulated driving performance tests (available for download; see Methods), field sobriety assessments, subjective drug effect questionnaires, a mobile device impairment test (DRUID app), and collection of whole blood specimens will be completed repeatedly during each session. Linear mixed models will be used to test for differences across experimental conditions and a priori planned comparisons will be used to determine differences between conditions of interest (e.g., cannabis alone vs cannabis with alcohol). This research is designed to extend prior studies of cannabis and alcohol on driving performance by using oral and vaporized routes of cannabis administration. By increasing understanding of impairment associated with co-use of alcohol and these novel forms of cannabis, this research could inform impairment detection standards for cannabis and alcohol and have important implications for law enforcement, public policy decisions regarding accessibility of these substances, and education of the general population who may use cannabis and/or alcohol. Lastly, this manuscript provides interested researchers with access to the simulated driving scenarios and data extraction tools developed for this study as a means of facilitating future cross-study comparisons, which is important given the heterogeneity in methods used across laboratories in prior research.

Binge and high-intensity drinking-Associations with intravenous alcohol self-administration and underlying risk factors.

Some styles of alcohol consumption are riskier than others. How the level and rate of alcohol exposure contribute to the increased risk of alcohol use disorder is unclear, but likely depends on the alcohol concentration time course. We hypothesized that the brain is sensitive to the alcohol concentration rate of change and that people at greater risk would self-administer faster. We developed a novel intravenous alcohol self-administration paradigm to allow participants direct and reproducible control over how quickly their breath alcohol concentration changes. We used drinking intensity and the density of biological family history of alcohol dependence as proxies for risk. Thirty-five alcohol drinking participants aged 21-28 years provided analytical data from a single, intravenous alcohol self-administration session using our computer-assisted alcohol infusion system rate control paradigm. A shorter time to reach 80 mg/dl was associated with increasing multiples of the binge drinking definition (p = 0.004), which was in turn related to higher density of family history of alcoholism (FHD, p = 0.04). Rate-dependent changes in subjective response (intoxication and stimulation) were also associated with FHD (each p = 0.001). Subsequently, given the limited sample size and FHD range, associations between multiples of the binge drinking definition and FHD were replicated and extended in analyses of the Collaborative Study on the Genetics of Alcoholism database. The rate control paradigm models binge and high-intensity drinking in the laboratory and provides a novel way to examine the relationship between the pharmacokinetics and pharmacodynamics of alcohol and potentially the risk for the development of alcohol use disorders.

The detrimental impact of alcohol intoxication on facets of Miranda comprehension.

Law enforcement officers often encounter alcohol-intoxicated suspects, suggesting that many suspects are presented with the challenge of grasping the meaning and significance of their Miranda rights while intoxicated. Such comprehension is crucial, given that Miranda is intended to minimize the likelihood of coercive interrogations resulting in self-incrimination and protect suspects' constitutional rights. Yet, the effects of alcohol on individuals' ability to understand and appreciate their Miranda rights remain unknown-a gap that the present study sought to address. Informed by alcohol myopia theory (AMT), we predicted that intoxicated individuals would demonstrate impaired Miranda comprehension compared to sober individuals and those who believed they were intoxicated (but were in fact not; i.e., placebo participants). After health screenings, participants completed the Wechsler Abbreviated Scale of Intelligence-Second Edition verbal subtests, rendering a Verbal Comprehension Index (VCI) score. We randomly assigned participants to consume alcohol (n = 51; mean breath alcohol concentration [BrAC] = 0.07%), a placebo condition (n = 44; BrAC = 0.00%), or a sober control condition (n = 41; BrAC = 0.00%). All participants (N = 136) completed the Miranda Rights Comprehension Instruments (MRCI), which measured participants' understanding of the Miranda warnings, recognition of the warnings, appreciation of their rights in interrogation and court settings, and understanding of Miranda-related vocabulary. We found a significant effect of intoxication condition on participants' understanding of Miranda warnings (η²p = .14) and Miranda-related vocabulary (η²p = .05) when controlling for VCI scores. Specifically, intoxicated participants received lower scores for understanding of warnings compared to sober and placebo participants, and lower scores for understanding of Miranda vocabulary compared to sober participants. Alcohol did not significantly impact Miranda rights recognition or appreciation. Alcohol intoxication may detrimentally impact some facets of Miranda comprehension. Thus, it is important that law enforcement consider refraining from questioning intoxicated suspects. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

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

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

The effects of post-learning alcohol ingestion on human motor memory consolidation.

The neurochemical mechanisms underlying motor memory consolidation remain largely unknown. Based on converging work showing that ethyl alcohol retrogradely enhances declarative memory consolidation, this work tested the hypothesis that post‐learning alcohol ingestion would enhance motor memory consolidation. In a within‐subject and fully counterbalanced design, participants (n = 24; 12M; 12F) adapted to a gradually introduced visual deviation and ingested, immediately after adaptation, a placebo (PBO), a medium (MED) or high (HIGH) dose of alcohol. The alcohol doses were bodyweight‐ and gender‐controlled to yield peak breath alcohol concentrations of 0.00% in the PBO, ~0.05% in the MED and ~0.095% in the HIGH condition. Retention was evaluated 24 h later through reach aftereffects when participants were sober. The results revealed that retention levels were neither significantly nor meaningfully different in both the MED and HIGH conditions as compared to PBO (all absolute Cohen's dz values < ~0.2; small to negligible effects), indicating that post‐learning alcohol ingestion did not alter motor memory consolidation. Given alcohol's known pharmacological GABAergic agonist and NMDA antagonist properties, one possibility is that these neurochemical mechanisms do not decisively contribute to motor memory consolidation. As converging work demonstrated alcohol's retrograde enhancement of declarative memory, the present results suggest that distinct neurochemical mechanisms underlie declarative and motor memory consolidation. Elucidating the neurochemical mechanisms underlying the consolidation of different memory systems may yield insights into the effects of over‐the‐counter drugs on everyday learning and memory but also inform the development of pharmacological interventions seeking to alter human memory consolidation.

Countries, national alcohol limits and risk behaviours: results from the TEN D by Night project

&#x0D; Background: this paper re-analysed data from the international cross-sectional TEN-D survey to investigate the association between country or national alcohol limits and risk behaviours.&#x0D; Methods: data were collected on subjects aged 16-35 years owning a driving license and attending recreational sites during weekend nights in Belgium/Netherlands, Bulgaria, Italy, Poland and Spain. Each participant was administered a: questionnaire, driving simulation, breath alcohol concentration (BAC) and illegal drugs detection tests. Random-effect regression was used to identify independent predictors of 3 outcomes: high BAC (≥0.5 g/L); negative driving behaviours; self-reported illegal drug consumption.&#x0D; Results: the survey included 4 534 subjects (mean age 23.1±4.2 years; males 68.3%). Alcohol misuse was highest in Poland (65.1%) and Spain (83.7%), which also showed the highest frequency of negative driving behaviours (39.0%) and illegal drugs consumption (55.6%). Multivariate analysis confirmed country as a predictor of all outcomes, whereas no association was found with national alcohol limits.&#x0D; Conclusions: the absence of association between national alcohol limits and alcohol misuse or negative driving behaviours suggests that cultural factors might be predominant in explaining the differences across countries. Our findings are preliminary and further research is needed.&#x0D;

Aminoxyl Catalyzed Electrochemical Ethanol Detection: Development of a New Breathalyzer Using Molecular Catalysis

Blood alcohol concentration (BAC) is the indicator of alcohol intoxication, and its measurement has emerged as the most common analytical procedure requested by law enforcement. Due to its volatility, ethanol vapor can be detected in breath, and its vapor concentration is proportional to BAC. Currently available instrumentation used for breath alcohol content (BrAC) analysis include gas chromatography (GC) and GC coupled with mass spectrometry, infrared (IR) spectroscopy, and fuel cell based electrochemical sensors. GC and IR spectroscopy devices have some drawbacks such as size, initial cost, and operational expense. Electrochemical sensors are capable of miniaturization and are available as portable and handheld breathalyzers. However, the lack of a single use and disposable sensing element, resulting memory effect and the need for frequent recalibration is the main drawback of currently available electrochemical breathalyzers. There have been few attempts at designing a sensing element to improve the current methods of alcohol detection by electrochemical techniques, all relying on enzymatic alcohol oxidation.1 Herein, we report a proof-of-concept non-enzymatic breathalyzer, harnessing the unique catalytic activity of the aminoxyl radical/oxoammonium redox couple toward alcohol oxidation.2 The relatively low redox potentials of aminoxyls, the mild conditions required for use, and their selective interactions with ethanol are their advantages compared to currently available Pt based breathalyzers. Our functional sensing element consists of a screen-printed electrode in which the graphene oxide-based working electrode is modified with aminoxyl derivatives, of which 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl benzoate (TMB) was the most efficient derivative. Exposing this modified electrode to simulated breath that contains ethanol, while applying the required potential for oxidation of the aminoxyl radical, generates an electrocatalytic current proportional to the ethanol concentration in the breath. These simple, sensitive, durable, and inexpensive electrodes may contribute to the development of a single-use reliable ethanol sensor for personal or law enforcement applications. Heikenfeld, J.; Jajack, A.; Rogers, J.; Gutruf, P.; Tian, L.; Pan, T.; Li, R.; Khine, M.; Kim, J.; Wang, J.; Kim, J. Wearable Sensors: Modalities, Challenges, and Prospects. Lab Chip 2018, 18, 217.Nutting, J. E.; Rafiee, M.; Stahl, S. S. Tetramethylpiperidine N-Oxyl (TEMPO), Phthalimide N-Oxyl (PINO), and Related N-Oxyl Species: Electrochemical Properties and Their Use in Electrocatalytic Reactions. Chem. Rev. 2018, 118, 4834.

A Study of Variability in Breath Alcohol Concentration and Brain Function Decline After Low Impact Drinking

A Study of Variability in Breath Alcohol Concentration and Brain Function Decline After Low Impact Drinking

Preventive effects of standardized krill oil on alcohol hangovers in a clinical trial

• Intake of krill oil alleviated hangover symptoms including thirst and nausea. • Intake of krill oil decreased alcohol and acetaldehyde concentrations in blood. • The effects of krill oil on alcohol hangover might be due to its antioxidant capacity. • It is a potential ingredient as alleviation of alcohol hangover. In this study, we investigated the effect of standardized krill oil on alcohol hangover through a placebo-controlled, randomized, double-blind, and crossover clinical trial. Hangover symptoms including thirst and nausea were alleviated by krill oil at 3 and 4 h, and at 0.5 and 1 h after the alcohol consumption, respectively (p < 0.05). The breath and blood alcohol concentrations, and Acetaldehyde levels in plasma from the krill oil group were significantly lower than those from the placebo at 1, 3, and 5 h, and at 1, 4, and 5 h, and at 0.5 h after the alcohol consumption, respectively (p < 0.05). Also, krill oil relatively increased alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity, and relatively lowered malondialdehyde (MDA) levels compared to placebo and positive control. Trolox equivalent antioxidant activity of krill oil was higher than the positive control. These results suggest that krill oil can be used as a potential anti-hangover ingredient.

The effects of acute alcohol administration on circulating endocannabinoid levels in humans.

Several lines of evidence suggest that endocannabinoid signalling may influence alcohol consumption. Preclinical studies have found that pharmacological blockade of cannabinoid receptor 1 leads to reductions in alcohol intake. Furthermore, variations in endocannabinoid metabolism between individuals may be associated with the presence and severity of alcohol use disorder. However, little is known about the acute effects of alcohol on the endocannabinoid system in humans. In this study, we evaluated the effect of acute alcohol administration on circulating endocannabinoid levels by analysing data from two highly-controlled alcohol administration experiments. In the first within-subjects experiment, 47 healthy participants were randomized to receive alcohol and placebo in a counterbalanced order. Alcohol was administered using an intravenous clamping procedure such that each participant attained a nearly identical breath alcohol concentration of 0.05%, maintained over 3 h. In the second experiment, 23 healthy participants self-administered alcohol intravenously; participants had control over their exposure throughout the paradigm. In both experiments, circulating concentrations of two endocannabinoids, N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), were measured at baseline and following alcohol exposure. During the intravenous clamping procedure, acute alcohol administration reduced circulating AEA but not 2-AG levels when compared to placebo. This finding was confirmed in the self-administration paradigm, where alcohol reduced AEA levels in an exposure-dependent manner. Future studies should seek to determine whether alcohol administration has similar effects on brain endocannabinoid signalling. An improved understanding of the bidirectional relationship between endocannabinoid signalling and alcohol intake may deepen our understanding of the aetiology and repercussions of alcohol use disorder.

An Abstract Parabolic System-Based Physics-Informed Long Short-Term Memory Network for Estimating Breath Alcohol Concentration from Transdermal Alcohol Biosensor Data.

The problem of estimating breath alcohol concentration based on transdermal alcohol biosensor data is considered. Transdermal alcohol concentration provides a promising alternative to classical methods such as breathalyzers or drinking diaries. A physics-informed long Short-term memory (LSTM) network with covariates for the solution of the estimation problem is developed. The data-driven nature of an LSTM is augmented with a first principles physics-based population model for the diffusion of ethanol through the epidermal layer of the skin. The population model in an abstract parabolic framework appears as part of a regularization term in the loss function of the LSTM. While learning, the model is encouraged to both fit the data and to produce physically meaningful outputs. To deal with the high variation observed in the data, a mechanism for the uncertainty quantification of the estimates based on a recently discovered relation between Monte-Carlo dropout and Bayesian learning is used. The physics-based population model and the LSTM are trained and tested using controlled laboratory collected breath and transdermal alcohol data collected in four sessions from 40 orally dosed participants (50% female, ages 21 - 33 years, 35% BMI above 25.0) resulting in 256 usable drinking episodes partitioned into training and testing sets. Body measurement (e.g. BMI, hip to waist ratio, etc.), personal (e.g. sex, age, race, etc.), drinking behavior (e.g. frequent, rarely, etc.), and environmental (e.g. temperature, humidity, etc.) covariates were also collected from participants. The importance of various covariates in the estimation is investigated using Shapley values. It is shown that the physics-informed LSTM network can be successfully applied to drinking episodes from both the training and test set, and that the physics-based information leads to better generalization ability on new drinking episodes with the uncertainty quantification yielding credible bands that effectively capture the true signal. Compared to two machine learning models from previous studies, the proposed model reduces relative error in estimated breath alcohol concentration by 58% and 72%, and relative peak error by 33% and 76%.

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.

0221 Pre-Sleep Breath alcohol concentrations (psBrAC) and sleep polysomnography (PSG)

Abstract Introduction Alcohol use before bedtime has been shown to alter sleep including decreasing sleep latency, decreasing sleep efficiency, and fragmenting sleep stage distribution. Few studies manipulate pre-sleep alcohol concentration, instead focusing on a target dose or peak alcohol concentration during the night. Thus, we investigated how presleep breath alcohol concentrations (psBrAC) level (targeting a BrAC of 0.08), are associated with same-night sleep. Methods Thirty (15F; ages=22-57, mean=33yr) healthy adults who self-reported moderate drinking were instructed to maintain a consistent sleep schedule (8-9h time in bed) for a least 7-days before entering a cross-over design involving two sets (separated by&amp;gt;3 days) of 3 consecutive nights of in-lab polysomnography. For all nights in each condition, participants drank either mixer alone or mixer+alcohol in 3 portions across 45 minutes ending 1h before lights out. psBrAC was measured within 5 minutes of lights out. PSGs were staged according to Rechtschaffen and Kales (1968). We computed: slow wave sleep (SWS) and REM as percentages of total sleep for the full night (%SWS) &amp; (%REM), %SWS in the first third of the night (%SWST1), %REM in the last third of the night (%REMT3), minutes until sleep onset from lights out (Sleep Latency), and minutes after sleep onset until REM onset. Linear regressions tested if psBrAC on the first mixer+alcohol night predicted changes in sleep using the average of the three nights of sleep in the mixer-only condition as a covariate. Results psBrAC values ranged from 0.038 to 0.087 (mean = 0.066) mg/L. We identified minimal influence of BrAC on sleep: % SWS (β = -0.78; p = 0.07), % REM (β = 0.032; p = 0.96), % SWS T1 (β = -0.52; p = 0.522), % REM T3 (β = -1.01; p = 0.125), REM latency (β = 3.95; p = 0.302), and sleep latency (β = -1.23; p = 0.13). Conclusion These findings indicate that psBrAC was not associated with any of our sleep variables, when adjusting for sleep on nights without alcohol. Future work will examine peak BrAC as well whether the effects observed change over multiple nights of pre-sleep alcohol consumption. Support (If Any) R01AA025593

Separate and combined effects of alcohol and cannabis on mood, subjective experience, cognition and psychomotor performance: A randomized trial

Co-use of alcohol and cannabis is associated with increased frequency and intensity of use and related problems. This study examined acute effects of alcohol and cannabis on mood, subjective experience, cognition, and psychomotor performance. Twenty-eight healthy cannabis users aged 19–29 years with recent history of binge drinking completed this within-subjects, double-blind, double-dummy, placebo-controlled, randomized clinical trial. Participants received: placebo alcohol and placebo cannabis (<0.1% THC); alcohol (target breath alcohol content [BrAC] 80 mg/dL) and placebo cannabis; placebo alcohol and active cannabis (12.5% THC); and active alcohol and cannabis over four sessions. Profile of Mood States (POMS), Addiction Research Centre Inventory (ARCI), verbal free recall (VFR), Digit Symbol Substitution Test (DSST), Continuous Performance Test (CPT), and grooved pegboard (GPB) task were administered before and approximately 75 min after drinking alcohol (1 h after smoking cannabis ad libitum). Significant effects of condition were found for the POMS (Tension-Anxiety, Confusion) and ARCI (MBG, LSD, PCAG, Euphoria, Sedation), predominantly with greater increases emerging after cannabis or alcohol-cannabis combined relative to placebo. Significant effects were found for VFR (immediate total and delayed recall, percent retained), DSST (trials attempted, trials correct, reaction time), and GPB (non-dominant hand) predominantly with greater declines in performance after alcohol and alcohol-cannabis combined relative to placebo and/or cannabis. Cannabis appeared to affect mood and subjective experience, with minimal impact on cognitive performance. Alcohol appeared to impair cognitive and psychomotor performance, with minimal impact on mood and subjective experience. Acute effects of alcohol and cannabis combined were additive at most.