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.

Understanding use of e-cigarettes for smoking cessation among a sample of US adults.

INTRODUCTION: Many adults who smoke cigarettes report trying e-cigarettes to quit smoking. Understanding the use of e-cigarettes for smoking cessation and the type of support that adults desire when trying to quit smoking is important for supporting cessation attempts and maximizing smoking abstinence. METHODS: In summer 2021, an online survey of 857 adults who reported a history of regular cigarette smoking and endorsed using e-cigarettes in a recent smoking cessation attempt was conducted. Survey items assessed reasons for using e-cigarettes to quit smoking, what was helpful about e-cigarettes, and what information participants desired when using e-cigarettes to quit smoking. RESULTS: Common reasons for using e-cigarettes to quit smoking included beliefs that vaping would be helpful for quitting (53.6%), vaping is safer than smoking (50.5%), and favorable comparisons relative to other nicotine replacement treatment (NRT) like nicotine patches and gum (24.7%). 23.8% selected e-cigarettes because they were cheaper than other smoking cessation aids. 89% of participants reported still smoking cigarettes at the time of survey. The most common information people wanted when quitting was advice on how to gradually reduce nicotine over time to become nicotine-free (46.3%), how different vaping devices work (39.7%), and what nicotine concentration to start with (37.7%). CONCLUSIONS: Findings identified common beliefs about e-cigarettes as a smoking cessation aid and how they compare to other treatments including NRT. Understanding factors that support cessation are critical especially due to high relapse rates. Results may help to inform support programs, especially for individuals who are interested in using e-cigarettes to quit smoking. IMPLICATIONS: Despite greater reporting, there is a limited understanding of e-cigarette use for quitting among those who smoke cigarettes.Our study highlights the reasons for using e-cigarettes among those who have recently tried e-cigarettes for quitting smoking, and the components of e-cigarette that were helpful.We also examined the desired support in a program designed to use e-cigarettes for quitting smoking. Majority of participants who attempted to quit smoking using an e-cigarette relapsed to smoking, indicating the gap in cessation support that can be filled with greater understanding of the desired support.

Words matter: descriptors for nicotine that comes from tobacco and descriptors for synthetic nicotine that is created in a laboratory differentially impact understanding of nicotine source and risk perceptions.

BACKGROUND: Nicotine products increasingly contain synthetic nicotine made in a lab (NML), not from tobacco. 'Tobacco-free nicotine' is most often used to describe NML commercially, but other descriptors are emerging (eg, 'non-tobacco,' 'zero-tobacco'). We examined whether terms for NML differentially impact public understanding of nicotine source or risk perceptions relative to each other and to terms for describing nicotine from tobacco (NFT) as 'tobacco-derived.' METHODS: From December 2022 to April 2023, 1000 participants aged 13 and older completed an online survey (mean age: 33.02 (SD=18.15) years, 50.5% female, 16.6% Hispanic, 67.4% White and 79.8% with current tobacco use). Participants read 11 terms describing nicotine and reported on perceived nicotine source (ie, NML, NFT) and addictiveness. Rank-ordered harm was included as a sensitivity analysis. RESULTS: Significant differences were observed among terms (eg, 'zero tobacco nicotine' and 'no tobacco nicotine' were rated as least addictive overall). 'NML' and 'NFT' adequately conveyed nicotine source and were rated as conveying comparable, yet high addictiveness, making them the optimal terms. CONCLUSIONS: Many terms for NML and NFT are differentially related to understanding nicotine source and risk perceptions even though no existing research indicates that NML and NFT differ meaningfully from each other on characteristics like addictiveness. In the absence of prohibiting product differentiation by nicotine source, regulatory agencies should promote using the terms 'Nicotine from Tobacco' and 'Nicotine Made in a Lab' and investigate whether products using descriptors conveying reduced harm (eg, 'zero-tobacco,' 'no-tobacco,' 'non-tobacco') should require review as Modified Risk Tobacco Products.

A randomized controlled trial of potential tobacco policies prohibiting menthol flavor in cigarettes and e-cigarettes: a study protocol.

BACKGROUND: Menthol cigarette use remains a large public health problem and disproportionately affects Black adults in the United States. The Food and Drug Administration has proposed prohibiting menthol flavor in cigarettes to protect public health. However, e-cigarettes are available in menthol flavor and are a popular alternative product adults might switch to if menthol is prohibited in cigarettes. Research is needed to understand how availability of menthol (vs. tobacco) flavored e-cigarettes could impact cigarette use among adults who smoke menthol cigarettes. METHODS: We will recruit 150 adults who currently smoke menthol cigarettes and will randomize them to 1 of 3 conditions modeling different regulatory scenarios. We will recruit equal numbers of participants identifying as Black vs. non-Black and will stratify randomization by race. To promote standardization and adherence, cigarette and e-cigarette products will be provided for 8 weeks based on the assigned condition: (A) no menthol restriction (menthol cigarette and menthol flavored e-cigarette), (B) menthol prohibited in cigarettes only (non-menthol cigarette and menthol flavored e-cigarette), (C) menthol prohibited in both cigarettes and e-cigarettes (non-menthol cigarette and tobacco flavored e-cigarette). A follow-up visit will occur at week 12 to assess tobacco use status. The study aims are to (1) examine the impact of prohibiting menthol flavor in cigarettes and e-cigarettes on smoking behavior and (2) investigate whether outcomes differ by race to understand the impact of menthol policies on Black (vs. non-Black) individuals given high rates of menthol cigarette use in this population. The primary outcome will evaluate changes in the number of cigarettes smoked per day during the 8-week study period and will examine differences by regulatory scenario. Secondary outcomes will compare percent days smoke-free, changes in nicotine dependence, and motivation, confidence, and intentions to quit smoking by the regulatory scenarios. We will examine whether changes in the outcomes differ by Black vs. non-Black participants to compare the magnitude of the effect of the various menthol policy scenarios by race. DISCUSSION: Results will contribute critical information regarding menthol in cigarettes and e-cigarettes to inform regulatory policies that maximize reductions in cigarette smoking and reduce tobacco-related health disparities. TRIAL REGISTRATION: NCT05259566. Yale IRB protocol #2000032211, last approved 12/8/2023.

Reductions in World Health Organization risk drinking level are associated with improvements in sleep problems among individuals with alcohol use disorder.

AIMS: Among individuals with alcohol use disorder (AUD), sleep disturbances are pervasive and contribute to the etiology and maintenance of AUD. However, despite increased attention toward the relationship between alcohol use and sleep, limited empirical research has systematically examined whether reductions in drinking during treatment for AUD are associated with improvements in sleep problems. METHODS: We used data from a multisite, randomized, controlled trial that compared 6 months of treatment with gabapentin enacarbil extended-release with placebo for adults with moderate-to-severe AUD (N = 346). The Timeline Follow-back was used to assess WHO risk drinking level reductions and the Pittsburgh Sleep Quality Index was used to assess sleep quality over the prior month at baseline and the end of treatment. RESULTS: Sleep problem scores in the active medication and placebo groups improved equally. Fewer sleep problems were noted among individuals who achieved at least a 1-level reduction (B = -0.99, 95% confidence interval (CI) [-1.77, -0.20], P = .014) or at least a 2-level reduction (B = -0.80, 95% CI [-1.47, -0.14], P = .018) in WHO risk drinking levels at the end of treatment. Reductions in drinking, with abstainers excluded from the analysis, also predicted fewer sleep problems at the end of treatment (1-level: B = -1.01, 95% CI [-1.83, -0.20], P = .015; 2-level: B = -0.90, 95% CI [-1.59, -0.22], P = .010). CONCLUSIONS: Drinking reductions, including those short of abstinence, are associated with improvements in sleep problems during treatment for AUD. Additional assessment of the causal relationships between harm-reduction approaches to AUD and improvements in sleep is warranted.

The Scientific Basis for the Regulation of Flavors in Tobacco Products.

Effective tobacco policies are important for reducing the harm of tobacco use and can have a broad impact at the population level. This review provides an overview of how clinical science can inform tobacco policies with a focus on policies related to flavored tobacco products, using menthol cigarettes as an illustrative example. Specifically, this review summarizes the role of flavors in tobacco use and the history of regulation of flavored tobacco products by the US Food and Drug Administration (FDA), provides an overview of clinical research methods used to contribute to the scientific evidence to inform FDA tobacco policies, discusses key findings related to menthol tobacco products using these methods, and proposes future directions for clinical research. As the tobacco marketplace continues to evolve with new products and flavor chemicals, ongoing clinical science will be essential for establishing evidence-based policies to protect public health and reduce tobacco-related health disparities.

E-cigarette Use Patterns, Flavors, and Device Characteristics Associated With Quitting Smoking Among a U.S. sample of Adults Using E-cigarettes in a Smoking Cessation Attempt.

INTRODUCTION: Many adults who smoke cigarettes use e-cigarettes to try to quit smoking; however, some are not successful. Identifying factors that are associated with successfully quitting smoking using e-cigarettes is important for maximizing cigarette cessation. AIMS AND METHODS: Online survey data were collected in 2021 from 857 adults in the United States who reported using e-cigarettes in a recent attempt to quit smoking. Survey items assessed patterns of e-cigarette use and device characteristics (flavors, device, and nicotine) used when trying to quit smoking. Multivariable linear regression models examined characteristics associated with the longest duration of smoking abstinence when using e-cigarettes to try to quit. RESULTS: The average duration of smoking abstinence when using e-cigarettes during a quit attempt was 65 days (SD = 104). In the multivariable model, greater frequency of e-cigarette use when quitting and abruptly switching to e-cigarettes from cigarettes (vs. gradually reducing) were significantly associated with longer durations of abstinence (p < .001). Preference for non-tobacco (relative to tobacco) flavors and nicotine concentration were not associated with duration of abstinence, although preference for rechargeable pod and mod device types (vs. cig-a-likes) was associated with longer durations of abstinence. CONCLUSIONS: Patterns of e-cigarette use were related to abstinence duration, which may provide guidance for adults who are using e-cigarettes to quit smoking to encourage complete substitution and maximize smoking cessation. Findings indicate that non-tobacco e-cigarette flavors and nicotine strength are not related to longer durations of cessation success for adults, which may inform tobacco regulatory policies limiting these constituents to protect public health. IMPLICATIONS: This study provides important new information about the characteristics of e-cigarettes used during an attempt to quit smoking among adults across the United States and identifies factors associated with quitting success. Patterns of e-cigarette use were associated with longer durations of abstinence. In contrast, few e-cigarette characteristics were associated with abstinence. Although preference for some pod and mod device types was associated with longer abstinence duration compared to earlier cig-a-like devices, preference for non-tobacco (vs. tobacco) flavor and nicotine concentration were not associated with abstinence. Findings may help inform guidance for adults using e-cigarettes to quit smoking and support tobacco regulatory policies.

Including the term 'tobacco-free nicotine' in the nicotine addiction warning label mandated by the US Food and Drug Administration alters risk perceptions and use intentions.

BACKGROUND: The US Food and Drug Administration (FDA) requires a warning label on nicotine e-cigarettes and pouches: 'This product contains nicotine. Nicotine is an addictive chemical'. Some brands marketing synthetic nicotine products have modified the warning ('This product contains tobacco-free nicotine (TFN)…'). The public health impact of altering the warning is unknown, so we examined its impact on risk perceptions and use intentions. METHODS: 1000 participants completed an anonymous online survey. Participants viewed the black-and-white FDA and TFN-modified warning labels in isolation, in a randomised order and reported on perceived addictiveness and, secondarily, use intentions. Participants then selected which label conveyed the most harm overall. Generalised estimating equations (GEEs) were used to evaluate the impact of label type and participant characteristics on perceived addictiveness and, secondarily, use intentions. Multivariable logistic regression was used to evaluate relationships between participant characteristics and choosing which label conveyed the most harm. RESULTS: Overall, the TFN-modified label was associated with lower addictiveness ratings but not increased use intentions. Where significant interactions between label type and participant characteristics emerged, TFN-modified labelling was associated with disproportionately reduced risk perceptions or increased use intentions among vulnerable populations (eg, underage individuals, racially minoritised groups). 25.5% of participants selected the TFN-modified label as conveying the most harm, with younger individuals (<21 years) significantly less likely to choose the TFN-modified label. CONCLUSIONS: Modifying the FDA-mandated nicotine warning label to include 'tobacco-free nicotine' may negatively impact public health, so the FDA should enforce inclusion of its original required warning label.

Harm reduction for smokers with little to no quit interest: can tobacco policies encourage switching to e-cigarettes?

OBJECTIVE: A pressing tobacco policy concern is how to help smokers who have little interest in quitting cigarettes, a group that often suffers severe health consequences. By switching from cigarettes to e-cigarettes, they could obtain nicotine, potentially with less harm. We examined if policy-relevant attributes of cigarettes/e-cigarettes might encourage these smokers to switch to e-cigarettes. METHODS: An online survey and discrete choice experiment on a nationally-representative sample of adult smokers in the US who reported low interest in quitting (n=2000). We modelled preference heterogeneity using a latent class, latent variable model. We simulated policies that could encourage switching to e-cigarettes. RESULTS: Participants formed two latent classes: (1) those with very strong preferences for their own cigarettes; and (2) those whose choices were more responsive to policies. The latter group's choices were only somewhat responsive to menthol cigarette bans and taxes; the former group's choices were unresponsive. CONCLUSIONS: The policies studied seem unlikely to encourage harm reduction for individuals with little interest in quitting smoking.

Synthetic cooling agent in oral nicotine pouch products marketed as 'Flavour-Ban Approved'.

BACKGROUND: US sales of oral nicotine pouches (ONPs) have rapidly increased, with cool/mint-flavoured ONPs the most popular flavour category. Restrictions on sales of flavoured tobacco products have either been implemented or proposed by several US states and localities. Zyn, the most popular ONP brand, is marketing Zyn Chill and Zyn Smooth as 'Flavour-Ban Approved' or 'unflavoured', probably to evade flavour bans and increase product appeal. At present, it is unclear whether these ONPs are indeed free of flavour additives that can impart pleasant sensations such as cooling. METHODS: Sensory cooling and irritant activities of 'Flavour-Ban Approved' Zyn ONPs, Chill and Smooth, along with minty varieties (Cool Mint, Peppermint, Spearmint, Menthol), were analysed by Ca2+ microfluorimetry in HEK293 cells expressing the cold/menthol (TRPM8) or menthol/irritant receptor (TRPA1). Flavour chemical content of these ONPs was analysed by gas chromatography/mass spectrometry. RESULTS: Zyn Chill ONP extracts robustly activated TRPM8, with much higher efficacy (39%-53%) than the mint-flavoured ONPs. In contrast, mint-flavoured ONP extracts elicited stronger TRPA1 irritant receptor responses than Chill extracts. Chemical analysis demonstrated that Chill exclusively contained WS-3, an odourless synthetic cooling agent, while mint-flavoured ONPs contained WS-3 together with mint flavourants. CONCLUSIONS: ONP products marketed as 'Flavour-Ban Approved' or 'unflavoured' contain flavouring agents, proving that the manufacturer's advertising is misleading. Synthetic coolants such as WS-3 can provide a robust cooling sensation with reduced sensory irritancy, thereby increasing product appeal and use. Regulators need to develop effective strategies for the control of odourless sensory additives used by the industry to bypass flavour bans.

Occupancy of the kappa opioid receptor by naltrexone predicts reduction in drinking and craving.

The efficacy of naltrexone to treat alcohol use disorder (AUD) is modest. A better understanding of the neurobiology underlying naltrexone effects could optimize treatments. We evaluated the occupancy of the kappa opioid receptor (KOR) by naltrexone measured with [11C]-LY2795050 positron emission tomography (PET) as a predictor of response to naltrexone. Response to naltrexone was defined as the difference in craving and the difference between the number of drinks consumed during an alcohol drinking paradigm (ADP) before and after 1 week of supervised 100 mg daily oral naltrexone. Forty-four (14 F) nontreatment seeking heavy drinkers meeting criteria for AUD were enrolled. Participants drank 47 ± 16 drinks per week and were balanced in family history of alcoholism (FH, 26 positive). High KOR occupancy (92 ± 1%) was achieved. Occupancy was negatively associated with number of years drinking (YOD) in FH positive, but not FH negative, participants (t3,42 = 4.00, p = 0.0003). Higher KOR occupancy by naltrexone was associated with higher alcohol craving during the ADP (F1,81 = 4.88, p = 0.030). The reduction in drinking after naltrexone was negatively associated with KOR occupancy, with significant effects of FH status (t1,43 = -2.08, p = 0.044). A logistic regression model including KOR occupancy, YOD, and FH variables achieved an 84% prediction accuracy for ≥50% reduction in drinking. These results confirm that naltrexone binds at the KOR site and suggest that KOR occupancy by naltrexone may be related to clinical response. Based on our results, we propose that differential affinities for the mu and KOR could explain why lower doses of naltrexone can have greater clinical efficacy.

Differences in the association between kappa opioid receptors and pain among Black and White adults with alcohol use disorders.

BACKGROUND: The relationship between alcohol and pain is complex. Associations between pain and alcohol use disorder (AUD) vary by race, but the underlying biological basis is not understood. We examined the association of the kappa opioid receptor (KOR) with responses to the cold-pressor test (CPT), before and after treatment with the opioid antagonist naltrexone, among individuals with AUD who self-identified as Black or White. METHODS: Thirty-seven individuals (12 Black, 24 White, and 1 Multiracial) with AUD participated in two CPTs, separated by 1 week during which they received naltrexone 100 mg daily. During each CPT, pain reporting threshold (PRT), average pain increase rate (APIR), relative pain recovery (RPR), and alcohol craving were recorded. KOR availability was measured using [11 C]-LY2795050 positron emission tomography (PET) prior to treatment with naltrexone. RESULTS: Black participants reported higher PRT and APIR than White participants during the CPT before, but not after, naltrexone treatment. Among Black participants, KOR availability was positively associated with PRT and APIR before, but not after naltrexone. Greater KOR availability was associated with faster RPR for White, but not Black, participants. The CPT induced more alcohol craving in Black than White participants, particularly in individuals with low KOR availability, an effect that was not attenuated by naltrexone. CONCLUSIONS: KOR involvement and naltrexone effects on responses to the CPT were different between Black and White participants. These preliminary findings suggest that further exploration of the differences in the opioid system and pain among Black and White individuals with AUD and their relationship with naltrexone's effects is warranted.

Combination treatment with varenicline and naltrexone reduces World Health Organization risk drinking levels.

BACKGROUND: The U.S. Food and Drug Administration identifies abstinence and the absence of heavy drinking days as outcomes for pharmacotherapy trials for alcohol use disorder (AUD). However, many individuals with AUD struggle to achieve these outcomes, which may discourage them from seeking treatment. World Health Organization (WHO) risk drinking levels have garnered attention in the alcohol field as potential non-abstinent outcomes for AUD medication trials. Further, testing combination pharmacotherapy for AUD represents an important direction in the field, particularly using medications such as naltrexone and varenicline, which are approved for treating AUD and smoking, respectively. The objective of the current study was to test the utility of the WHO risk drinking levels as a drinking outcome in a randomized clinical trial of combined varenicline and naltrexone for smoking cessation and drinking reduction. These analyses provide additional tests of the efficacy of this combination treatment. METHODS: The current study is a secondary analysis of a phase 2, randomized, double-blind clinical trial, wherein participants (N = 165) who were daily smokers and heavy drinkers were randomly assigned to receive either 2 mg/day of varenicline plus 50 mg/day of naltrexone or 2 mg/day of varenicline plus placebo for 12 weeks. Medication effects on 1- and 2-level reductions in WHO risk drinking levels were assessed at 4, 8, and 12 weeks into the active medication period. RESULTS: In logistic growth curve models individuals receiving the combined treatment had greater reductions in WHO risk drinking levels than individuals taking varenicline alone when assessed at 4 weeks into the active medication period. Among individuals who were WHO high and very high risk drinkers at baseline, the largest effect sizes favoring combination treatment were at Week 4 for the WHO 2-level reduction outcome (Cohen's h = 0.202) and Week 12 for the WHO 1-level reduction outcome (Cohen's h = 0.244), although these effects did not reach statistical significance. CONCLUSIONS: These findings provide evidence that combined varenicline plus naltrexone treatment is effective at reducing WHO risk drinking levels, particularly among individuals who smoke cigarettes daily and drink heavily. These results add to a growing body of literature validating reductions in WHO risk drinking levels as outcomes of alcohol medication trials.

Predictors of abstinence, no heavy drinking days, and a 2-level reduction in World Health Organization drinking levels during treatment for alcohol use disorder in the COMBINE study.

BACKGROUND: Data from trials of medications for alcohol use disorder (AUD) can be used to identify predictors of drinking outcomes regardless of treatment, which can inform the design of future trials with heterogeneous populations. Here, we identified predictors of abstinence, no heavy drinking days, and a 2-level reduction in World Health Organization (WHO) drinking levels during treatment for AUD in the Combined Pharmacotherapies and Behavioral Interventions (COMBINE) Study. METHODS: We utilized data from the COMBINE Study, a randomized placebo-controlled trial evaluating the efficacy of naltrexone and acamprosate, both alone and in combination, for AUD (n = 1168). A tree-based machine learning algorithm was used to construct classification trees predicting abstinence, no heavy drinking days, and a 2-level reduction in WHO drinking levels in the last 4 weeks of treatment, based on 89 baseline variables. RESULTS: The final tree for predicting abstinence had one split based on consecutive days abstinent prior to randomization, with a higher proportion of subjects achieving abstinence among those classified as abstinent for >2 versus ≤2 consecutive weeks prior to randomization (66% vs. 29%). The final tree for predicting no heavy drinking days in the last 4 weeks of treatment had three splits based on consecutive days abstinent, age, and total Alcohol Dependence Scale score at baseline. Seventy-three percent of the subjects classified as abstinent for >2 consecutive weeks prior to randomization had no heavy drinking days in the last 4 weeks of treatment. Among those classified as abstinent ≤2 consecutive weeks prior, three additional splits showed that younger subjects (age ≤44 years; 37%), and older subjects (age >44) with a total Alcohol Dependence Scale score >13 and complete abstinence (56%) or other drinking goals (35%), were less likely to have no heavy drinking days than older subjects with a total Alcohol Dependence Scale score ≤13 (67%). The final tree for predicting a 2-level reduction in WHO levels had no splits. CONCLUSIONS: Consecutive days abstinent prior to randomization may predict abstinence and no heavy drinking days and total Alcohol Dependence Scale score and age may predict no heavy drinking days. The 2-level reduction in WHO levels outcome may be less likely to discriminate based on multiple patient characteristics.

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.

Sensitivity, specificity, and tolerability of the BACTrack Skyn compared to other alcohol monitoring approaches among young adults in a field-based setting.

BACKGROUND: There is a need for novel alcohol biosensors that are accurate, able to detect alcohol concentration close in time to consumption, and feasible and acceptable for many clinical and research applications. We evaluated the field accuracy and tolerability of novel (BACTrack Skyn) and established (Alcohol Monitoring Systems SCRAM CAM) alcohol biosensors. METHODS: The sensor and diary data were collected in a larger study of a biofeedback intervention and compared observationally in the present sub-study. Participants (high-risk drinkers, 40% female; median age 21) wore both Skyn and SCRAM CAM sensors for 1-6 days and were instructed to drink as usual. Data from the first cohort of participants (N = 27; 101 person-days) were used to find threshold values of transdermal alcohol that classified each day as meeting or not meeting defined levels of drinking (heavy, above-moderate, any). These values were used to develop scoring metrics that were subsequently tested using the second cohort (N = 20; 57 person-days). Data from both biosensors were compared to mobile diary self-report to evaluate sensitivity and specificity in relation to a priori standards established in the literature. RESULTS: Skyn classification rules for Cohort #1 within 3 months of device shipment showed excellent sensitivity for heavy drinking (94%) and exceeded expectations for above-moderate and any drinking (78% and 69%, respectively), while specificity met expectations (91%). However, classification worsened when Cohort #1 devices ≥3 months from shipment were tested (area under curve for receiver operator characteristic 0.87 vs. 0.79) and the derived classification threshold when applied to Cohort #2 was inadequately specific (70%). Skyn tolerability metrics were excellent and exceeded the SCRAM CAM (p ≤ 0.001). CONCLUSIONS: Skyn tolerability was favorable and accuracy rules were internally derivable but did not yield useful scoring metrics going forward across device lots and months of usage.

Multimodal neuroimaging of metabotropic glutamate 5 receptors and functional connectivity in alcohol use disorder.

BACKGROUND: People recovering from alcohol use disorder (AUD) show altered resting brain connectivity. The metabotropic glutamate 5 (mGlu5) receptor is an important regulator of synaptic plasticity potentially linked with synchronized brain activity and a target of interest in treating AUD. The goal of this work was to assess potential relationships of brain connectivity at rest with mGlu5 receptor availability in people with AUD at two time points early in abstinence. METHODS: Forty-eight image data sets were acquired with a multimodal neuroimaging battery that included resting-state functional magnetic resonance imaging (fMRI) and mGlu5 receptor positron emission tomography (PET) with the radiotracer [18 F]FPEB. Participants with AUD (n = 14) were scanned twice, at approximately 1 and 4 weeks after beginning supervised abstinence. [18 F]FPEB PET results were published previously. Primary comparisons of fMRI outcomes were performed between the AUD group and healthy controls (HCs; n = 23) and assessed changes over time within the AUD group. Relationships between resting-state connectivity measures and mGlu5 receptor availability were explored within groups. RESULTS: Compared to HCs, global functional connectivity of the orbitofrontal cortex was higher in the AUD group at 4 weeks of abstinence (p = 0.003), while network-level functional connectivity within the default mode network (DMN) was lower (p < 0.04). Exploratory multimodal analyses showed that mGlu5 receptor availability was correlated with global connectivity across all brain regions (HCs, r = 0.41; AUD group at 1 week of abstinence, r = 0.50 and at 4 weeks, r = 0.46; all p < 0.0001). Furthermore, a component of cortical and striatal mGlu5 availability was correlated with connectivity between the DMN and salience networks in HCs (r = 0.60, p = 0.003) but not in the AUD group (p > 0.3). CONCLUSIONS: These preliminary findings of altered global and network connectivity during the first month of abstinence from drinking may reflect the loss of efficient network function, while exploratory relationships with mGlu5 receptor availability suggest a potential glutamatergic relationship with network coherence.

Examining associations of e-cigarette flavour restrictions with e-cigarette use and success quitting smoking among US adults.

INTRODUCTION: Restricting available e-cigarette flavours to only tobacco and menthol may reduce appeal among youth; it is unknown how flavour restrictions impact adults using e-cigarettes to quit smoking cigarettes. METHODS: Online US survey data were collected in summer 2021 from 857 adults who reported using e-cigarettes in a recent attempt to quit smoking. Survey items assessed e-cigarette flavours used during their quit attempt, whether e-cigarette flavour bans restricted access to flavours they like, and what impact the restrictions had on e-cigarette behaviour. Multivariable logistic regression models were used to examine the associations of flavour bans with success quitting smoking for 1 month or longer. RESULTS: 30.2% (N=259) reported restricted access to e-cigarette flavours they like. During their quit attempt, 64.9% (N=168) used tobacco or menthol-flavoured e-cigarettes, and 90.7% (N=235) used another flavour that could be affected by restrictions, most commonly fruit, mint, and candy/dessert. Responses to flavour restrictions included switching devices to continue using preferred flavours (39.4%), using the same device only with available flavours (35.9%), buying preferred flavours elsewhere (eg, online) (19.3%), making flavours (3.5%) and 'other' (eg, no longer using e-cigarettes) (1.9%). The odds of quitting smoking for 1 month or longer were not significantly different between those experiencing flavour restrictions (vs not), preferring tobacco/menthol (vs restricted) flavour, or switching flavours in response to the bans (vs finding another way to obtain restricted flavours) (p>0.11). CONCLUSION: Experiencing e-cigarette flavour restrictions was not associated with success quitting smoking among adults using e-cigarettes to try to quit.

Stability of Drinking Reductions and Long-term Functioning Among Patients with Alcohol Use Disorder.

BACKGROUND: The World Health Organization (WHO) categorizes alcohol consumption according to grams consumed into low-, medium-, high-, and very-high-risk drinking levels (RDLs). Although abstinence has been considered the ideal outcome of alcohol treatment, reductions in WHO RDLs have been proposed as primary outcomes for alcohol use disorder (AUD) trials. OBJECTIVE: The current study examines the stability of WHO RDL reductions and the association between RDL reductions and long-term functioning for up to 3 years following treatment. DESIGN AND PARTICIPANTS: Secondary data analysis of patients with AUD enrolled in the COMBINE Study and Project MATCH, two multi-site, randomized AUD clinical trials, who were followed for up to 3 years post-treatment (COMBINE: n = 694; MATCH: n = 806). MEASURES: Alcohol use was measured via calendar-based methods. We estimated all models in the total sample and among participants who did not achieve abstinence during treatment. KEY RESULTS: One-level RDL reductions were achieved by 84% of patients at the end of treatment, with 84.9% of those individuals maintaining that reduction at a 3-year follow-up. Two-level RDL reductions were achieved by 68% of patients at the end of treatment, with 77.7% of those individuals maintaining that reduction at a 3-year follow-up. One- and two-level RDL reductions at the end of treatment were associated with significantly better mental health, quality of life (including physical quality of life), and fewer drinking consequences 3 years after treatment (p < 0.05), as compared to no change or increased drinking. CONCLUSION: AUD patients can maintain WHO RDL reductions for up to 3 years after treatment. Patients who had WHO RDL reductions functioned significantly better than those who did not reduce their drinking. These findings are consistent with prior reports suggesting that drinking reductions, short of abstinence, yield meaningful improvements in patient health, well-being, and functioning.

Mapping data-driven individualized neurobehavioral phenotypes in heavy alcohol drinkers.

OBJECTIVE: Recent studies have examined the factor structure and associated correlates of three neurofunctional domains, executive function, incentive salience, and negative emotionality in the development and maintenance of alcohol use disorders in clinical samples. The current study sought to replicate and extend prior work by testing this 3-factor model, utilizing both exact and similar phenotypic measures, as well as novel measures, in a non-treatment-seeking sample. METHODS: Self-report measures of alcohol addiction, impulsivity, behavior, and exposure to early-life stress were collected as part of baseline assessments for alcohol imaging and pharmacotherapy studies in 335 individuals. Confirmatory factor analysis (CFA) was used to examine model structure and fit. A multiple indicators, multiple causes (MIMIC) model identified predictors of latent factors identified by CFA. RESULTS: Results supported an intercorrelated model with three factors: executive function, incentive salience, and emotionality. All factors were associated with current AUD, and incentive salience was uniquely associated with past 30-day drinking frequency. MIMIC results identified multiple significant predictors of these latent factors, including history of alcohol use disorder, positive family history of alcohol dependence, earlier age of first drink, and a history of childhood emotional abuse and physical neglect. CONCLUSIONS: Our results support an intercorrelated 3-factor model of neurofunctional domains in alcohol use models, consistent with published findings. Because childhood physical neglect was a significant predictor of all latent factors, these results also highlight the significant negative impact of childhood neglect on later addiction development.