Characterizing reward and relief/habit drinking profiles in a study of naltrexone, varenicline, and placebo.

INTRODUCTION: This study aims to clarify differences in mood, craving, and treatment response between reward and relief/habit individuals in a study of naltrexone, varenicline, and placebo. We hypothesized that relief/habit individuals would have a poorer mood during early abstinence and higher levels of alcohol craving than reward individuals. We hypothesized that reward individuals would demonstrate better drinking outcomes on naltrexone versus placebo. METHODS: Data were culled from a randomized, double-blind, placebo-controlled human trial of 53 individuals (18F/16M) with alcohol use disorder randomized to varenicline (n = 19), naltrexone (n = 15), or matched placebo (n = 19). In this 6-day practice quit trial, participants attempted to abstain from drinking and completed daily diaries. Participants were classified into reward or relief/habit subgroups based on self-reported motivation for drinking. Multilinear models tested differences in mood and alcohol craving between reward and relief/habit individuals. General linear models tested differences between reward and relief/habit individuals' drinking outcomes on each medication versus placebo. RESULTS: Relief/habit individuals showed decreases in positive mood and increases in negative mood over the quit attempt across medications, compared to reward individuals (P's < .05). Reward individuals' tension decreased on naltrexone, while relief/habit individuals' tension remained stable (F = 3.64, P = .03). Reward individuals in the placebo group had higher percent days abstinent than relief individuals in the placebo group (P < .001). DISCUSSION: This study suggests relief/habit individuals' mood worsens during early abstinence. Our finding that reward individuals' tension decreased on naltrexone and increased on placebo may suggest a clinical response to the medication.

Influence of sleep quality on lapse to alcohol use during a quit attempt.

AIMS: Sleep problems are common among individuals with alcohol use disorder (AUD) and is often associated with a heightened relapse risk. The present study examines the relationship between sleep and alcohol use among individuals with current AUD during a 6-day quit attempt as part of a medication study. METHODS: The current study is a secondary analysis of a medication trial for individuals with AUD. Individuals with AUD (N = 53, 26 females) were randomized to active medication or matched placebo. Randomized participants completed a week-long medication titration (Days 1-7). Following the titration period, participants attended an in-person visit (Day 8) to begin a 6-day quit attempt. During the quit attempt, participants completed daily diary assessments to report on previous day alcohol consumption, sleep quality, and alcohol craving. In the present study, medication condition was controlled for in all models. RESULTS: Baseline global sleep quality was not a significant predictor of drinks per drinking day (P = 0.72) or percent days abstinent (P = 0.16) during the 6-day practice quit attempt. Daily diary analyses found that greater sleep quality was associated with higher next-day drinks per drinking day (b = 0.198, P = 0.029). In contrast, participants reported worse sleep quality following nights of greater alcohol intake, albeit at a trend-level (b = -0.12, P = 0.053). CONCLUSIONS: These results suggest that better sleep quality was a risk factor for drinking during the 6-day quit period, such that better sleep may be associated with increased craving for alcohol and alcohol use the next day. These findings are limited to the early abstinence period and should be considered in studies exploring longer periods of abstinence.

Reward, relief, and habit drinking profiles in treatment seeking individuals with an AUD.

AIMS: This study aimed to compare reward, relief, and habit treatment-seeking individuals on recent drinking, alcohol use disorder (AUD) phenomenology, and mood. The second aim of the study was to evaluate the predictive validity of reward, relief, and habit profiles. METHOD: Treatment-seeking individuals with an AUD (n = 169) were recruited to participate in a medication trial for AUD (NCT03594435). Reward, relief, and habit drinking groups were assessed using the UCLA Reward Relief Habit Drinking Scale. Group differences at baseline were evaluated using univariate analyses of variance. A subset of participants were enrolled in a 12-week, double-blind, placebo-controlled medication trial (n = 102), and provided longitudinal drinking and phenomenology data. The predictive validity of group membership was assessed using linear regression analyses. RESULTS: At baseline, individuals who drink primarily for relief had higher craving and negative mood than those who drink for reward and habit. Prospectively, membership in the relief drinking group predicted greater alcohol use, greater heavy drinking, and fewer days abstinent compared to those in the reward drinking group. Membership in the relief drinking group also predicted greater alcohol craving, more alcohol-related consequences, and more anxiety symptoms over 12 weeks compared to those in the reward drinking group. CONCLUSIONS: This study provides support for reward and relief drinking motive profiles in treatment-seeking individuals with an AUD. Membership in the relief drinking motive group was predictive of poorer drinking outcomes and more negative symptomology over 12 weeks, indicating that individuals who drink for relief may be a particularly vulnerable sub-population of individuals with AUD.

Alcohol Craving and Severity are Associated with Dorsal Anterior Cingulate Choline Levels in Individuals with an Alcohol Use Disorder.

AIMS: Magnetic resonance spectroscopy (MRS) has been used to probe inflammation in the brain. While altered MRS metabolite levels have previously been found in individuals with alcohol use disorder (AUD), the relationship between potential metabolite markers of inflammation and the clinical correlates of AUD remains understudied. Therefore, this exploratory study sought to elucidate the clinical significance of inflammation in AUD by examining relationships between metabolites, AUD severity, alcohol consumption, and craving in individuals with AUD. METHODS: Data for this secondary analysis are derived from a two-week clinical trial of ibudilast to treat AUD. Forty-three non-treatment-seeking individuals with an AUD (26M/17F) completed an MRS scan and alcohol-related questionnaires. MRS was performed using a multi-voxel array placed above the corpus callosum, extending from the pregnenual anterior cingulate to premotor cortex. The dorsal anterior cingulate was selected as the volume of interest. Metabolite levels of choline-compounds (Cho), myo-inositol (mI), and creatine+phosphocreatine (Cr) were quantified. Separate hierarchical regression models were used to evaluate the independent effects of metabolite levels on alcohol craving, alcohol problem severity, and alcohol consumption. RESULTS: Dorsal anterior cingulate Cho predicted alcohol craving and alcohol problem severity over and above demographics, medication, and alcohol consumption measures. mI and Cr did not predict alcohol craving or alcohol problem severity. Metabolite markers were not predictive of alcohol consumption. CONCLUSIONS: This preliminary study indicates that dACC Cho is sensitive to clinical characteristics of AUD. This is a further step in advancing neurometabolites, particularly Cho, as potential biomarkers and treatment targets for AUD.

Baseline C-reactive protein levels are predictive of treatment response to a neuroimmune modulator in individuals with an alcohol use disorder: a preliminary study.

Background: Inflammation is implicated in alcohol use disorder (AUD). Ibudilast, a neuroimmune modulator, shows promise for the treatment of AUD. Elevated inflammation, indicated by high levels of C-reactive protein (CRP), represents a possible subtype of AUD, which may be associated with treatment response to ibudilast.Objectives: The current study evaluated CRP as a predictor of treatment response to ibudilast; hypothesizing that ibudilast would be more effective at reducing drinking and alcohol cue-reactivity in individuals with higher CRP levels.Methods: This is a secondary analysis of a clinical trial of ibudilast for AUD, which found that ibudilast reduced heavy drinking in individuals with AUD. Fifty-one individuals were randomized to receive ibudilast (n = 24 [16 M/8F]) or placebo (n = 27 [18 M/9F]) for two weeks. Participants provided blood samples at baseline to assess CRP levels, completed daily assessments of alcohol use, and an fMRI alcohol cue-reactivity task at study mid-point. Models tested the effects of medication, CRP levels, and their interaction on drinks per drinking day and alcohol cue-reactivity.Results: There was a significant interaction between medication and CRP (F = 3.80, p = .03), such that the ibudilast high CRP group had fewer drinks per drinking day compared to the ibudilast low CRP group. CRP moderated the effect of medication on brain activation in a cluster extending from the left inferior frontal gyrus to the right-dorsal striatum (Z = 4.55, p < .001). This interaction was driven by attenuated cue-reactivity in the ibudilast high CRP group relative to the ibudilast low CRP and placebo high CRP groups.Conclusions: This study serves as an initial investigation into predictors of clinical response to ibudilast treatment and suggests that a baseline proinflammatory profile may enhance clinical efficacy.

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.

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.

The effect of neuroimmune modulation on subjective response to alcohol in the natural environment.

BACKGROUND: Despite the promising implications for novel immune therapeutics, few clinical trials have tested these therapies to date. An understanding of how immune pharmacotherapies influence complex alcohol use disorder (AUD) profiles, including subjective response to alcohol, is very limited. Initial findings show that ibudilast, a neuroimmune modulator, reduces rates of heavy drinking and measures of alcohol craving. METHODS: This study is a secondary analysis of a 2-week clinical trial of ibudilast that enrolled a nontreatment-seeking sample with AUD. Eligible participants (N = 52) were randomized to receive ibudilast or matched placebo and completed daily diary assessments (DDAs) during the 2-week period. Each morning, participants reported on their mood and craving levels both before and during the previous day's drinking episode, as well as stimulation and sedation levels during the previous day's drinking episode. Multilevel models were used to compare the effects of ibudilast and placebo on subjective alcohol response. Exploratory analyses tested whether ibudilast moderated the relationship between daily stimulation/sedation and alcohol intake and whether withdrawal-related dysphoria moderated ibudilast's effects on subjective response. RESULTS: Ibudilast did not significantly alter mean levels of stimulation or sedation (p's > 0.05). It did, however, moderate the effect of daily stimulation on drinking (p = 0.045). Ibudilast attenuated alcohol-induced increases in craving compared with placebo (p = 0.047), but not other subjective response measures. Ibudilast significantly tempered daily alcohol-induced changes in urge to drink and positive mood only among individuals without withdrawal-related dysphoria. CONCLUSIONS: Ibudilast's effects on subjective alcohol responses appear to be nuanced and perhaps most salient for individuals drinking for positive reinforcement as distinguished from those who drink to feel normal. Consistent with previous findings, reductions in alcohol craving may represent a primary mechanism of ibudilast's effects on drinking. The ecologically valid nature of DDAs provide a clinically useful window into how individuals experience alcohol's effects while taking ibudilast.

Alcohol use trajectories among U.S. adults during the first 42 weeks of the COVID-19 pandemic.

BACKGROUND: This study characterized the prevalence, drinking patterns, and sociodemographic characteristics of U.S. adult subpopulations with distinct drinking trajectories during the COVID-19 pandemic's first 42 weeks. METHODS: Adult respondents (n = 8130) in a nationally representative prospective longitudinal study completed 21 biweekly web surveys (March 2020 to January 2021). Past-week alcohol drinking frequency (drinking days [range: 0 to 7]) and intensity (binge drinking on usual past-week drinking day [yes/no]) were assessed at each timepoint. Growth mixture models identified multiple subpopulations with homogenous drinking trajectories based on mean drinking days or binge drinking proportional probabilities across time. RESULTS: Four drinking frequency trajectories were identified: Minimal/stable (72.8% [95% CI = 71.8 to 73.8]) with <1 mean past-week drinking days throughout; Moderate/late decreasing (6.7% [95% CI = 6.2 to 7.3) with 3.13 mean March drinking days and reductions during summer, reaching 2.12 days by January 2021; Moderate/early increasing (12.9% [95% CI = 12.2 to 13.6) with 2.13 mean March drinking days that increased in April and then plateaued, ending with 3.20 mean days in January 2021; and Near daily/early increasing (7.6% [95% CI = 7.0 to 8.2]) with 5.58 mean March drinking days that continued increasing without returning to baseline. Four drinking intensity trajectories were identified: Minimal/stable (85.8% [95% CI = 85.0% to 86.5%]) with <0.01 binge drinking probabilities throughout; Low-to-moderate/fluctuating (7.4% [95% CI = 6.8% to 8%]) with varying binge probabilities across timepoints (range:0.12 to 0.26); Moderate/mid increasing (4.2% [95% CI = 3.7% to 4.6%]) with 0.39 April binge drinking probability rising to 0.65 during August-September without returning to baseline; High/early increasing trajectory (2.7% [95% CI = 2.3% to 3%]) with 0.84 binge drinking probability rising to 0.96 by June without returning to baseline. Males, Whites, middle-aged/older adults, college degree recipients, those consistently working, and those above the poverty limit were overrepresented in various increasing (vs. minimal/stable) frequency trajectories. Males, Whites, nonmarried, those without college degree, 18 to 39-year-olds, and middle aged were overrepresented in increasing (vs. minimal/stable) intensity trajectories. CONCLUSIONS: Several distinct U.S. adult sociodemographic subpopulations appear to have acquired new drinking patterns during the pandemic's first 42 weeks. Frequent alcohol use assessment in the COVID-19 era could improve personalized medicine and population health efforts to reduce drinking.

The Brief Alcohol Use Disorder Severity Scale: An Initial Validation Evaluation.

AIMS: The goal of this study was to develop a standard measure of AUD severity that includes multiple dimensions and can be used in clinical settings to inform treatment selection. METHODS: A large sample (n = 1939) of moderate to heavy drinkers was amassed from six psychopharmacology studies. The severity factor was comprised of four dimensions: withdrawal, craving, AUD symptoms and alcohol-related consequences. First, a confirmatory factor analysis (CFA) was conducted to examine model fit. Next, a comprehensive item list from the four measures (i.e. CIWA, DrinC, PACs and SCID-5 AUD criteria) was reduced through exploratory factor analysis (EFA). Once the final items were merged into a preliminary assessment, an EFA was run to observe the factor structure. Initial validation of the measure was obtained via associations with clinical endpoints. RESULTS: The chi-square test statistic (${\chi}^2(2)=2.432\ P=0.297$) for a single-factor model of severity demonstrated good fit. Additional goodness-of-fit indices from the CFA revealed similar support for the single-factor model of severity (i.e. SRMSR = 0.011; RMSEA = 0.011; CFI = 0.999). Next, nine items from the individual EFAs were selected based on factor loading. The final EFA conducted on the 9-item scale demonstrated that a single factor model of severity best fit the data. Analysis of the psychometric properties revealed good internal consistency ($\alpha$= 0.79). CONCLUSIONS: The current study extends upon the measurement of severity and supports a brief severity measure. This brief 9-item scale can be leveraged in future studies as a screening instrument and as a tool for personalized medicine.

The Effects of Menstrual Cycle Hormones on Responses to Varenicline and Naltrexone Among Female Heavy Drinking Smokers.

AIMS: Women often experience poorer smoking cessation outcomes in comparison to men. Menstrual cycle phase and sex hormones may influence smoking behavior and alter response to opioid antagonist medications. Less is known about the effects of sex hormones in response to pharmacotherapy for female heavy drinking smokers. METHODS: This study is a secondary analysis of premenopausal female heavy drinking smokers who completed a 12-week randomized clinical trial comparing varenicline plus placebo versus varenicline plus naltrexone for smoking cessation and drinking reduction. Participants (n = 26; total observations = 66) provided saliva samples for assays of progesterone (P4) and estradiol (E2) post-randomization at Weeks 4, 8 and 12. We examined the effects of P4/E2 ratio and medication on smoking and drinking outcomes. RESULTS: For drinking outcomes, there was a significant interaction for percent days abstinent (b = 0.017, P = 0.05), suggesting that greater P4/E2 ratio is associated with greater percent days abstinent for women assigned to the varenicline plus naltrexone condition. There were no interaction effects for the remaining drinking outcomes (P's ≥ 0.12). Results found no significant interaction effect of P4/E2 ratio and medication on smoking abstinence (P = 0.19). CONCLUSION: Our results imply that when women show a greater P4/E2 ratio, typically observed during the luteal phase of the menstrual cycle, they experience an added benefit of naltrexone, versus placebo, for drinking outcomes as shown by greater percent days abstinent. Additional studies in larger samples are warranted as sex hormones offer important information above and beyond comparing women versus men.

Pain Catastrophizing Is Associated With Increased Alcohol Cue-Elicited Neural Activity Among Individuals With Alcohol Use Disorder.

AIMS: The current study examined the association between pain catastrophizing and alcohol cue-elicited brain activation in individuals with alcohol use disorder (AUD). METHODS: Non-treatment seeking heavy drinkers with AUD (n = 45; 28 males) completed self-report measures of pain catastrophizing and alcohol use/problems as part of a clinical trial of the neuroimmune modulator ibudilast. Participants were randomized to either placebo (n = 25) or ibudilast (n = 20) and completed an functional magnetic resonance imaging (fMRI) scan to assess neural activation to alcohol cues 1 week into the medication trial. Multiple linear regression examined whether pain catastrophizing predicted cue-induced activation in a priori regions of interest, namely the dorsal and ventral striatum (VS). An exploratory whole-brain analysis was conducted to assess the relationship between pain catastrophizing and neural alcohol cue reactivity. RESULTS: Pain catastrophizing predicted greater cue-induced activation in the dorsal (b = 0.006; P = 0.03) but not VS controlling for medication. Pain catastrophizing was positively associated with neural activation to alcohol cues in regions including the bilateral thalamus, left precuneus and left frontal pole. CONCLUSION: Greater pain catastrophizing is associated with greater cue-induced neural activation in brain regions sub-serving habits and compulsive alcohol use. These findings provide initial support for a neural mechanism by which pain catastrophizing may drive alcohol craving among individuals with AUD.

A Meta-Regression of Trial Features Predicting the Effects of Alcohol Use Disorder Pharmacotherapies on Drinking Outcomes in Randomized Clinical Trials: A Secondary Data Analysis.

AIMS: To test whether two critical design features, inclusion criteria of required pre-trial abstinence and pre-trial alcohol use disorder (AUD) diagnosis, predict the likelihood of detecting treatment effects in AUD pharmacotherapy trials. METHODS: This secondary data analysis used data collected from a literature review to identify randomized controlled pharmacotherapy trials for AUD. Treatment outcomes were selected into abstinence and no heavy drinking. Target effect sizes were calculated for each outcome and a meta-regression was conducted to test the effects of required pre-trial abstinence, required pre-trial AUD diagnosis, and their interaction on effect sizes. A sub-analysis was conducted on trials, which included FDA-approved medications for AUD. RESULTS: In total, 118 studies testing 19 medications representing 21,032 treated participants were included in the meta-regression analysis. There was no significant effect of either predictor on abstinence or no heavy drinking outcomes in the full analysis or in the sub-study of FDA-approved medications. CONCLUSION: By examining these design features in a quantitative, rather than qualitative, fashion the present study advances the literature and shows that requiring AUD diagnosis or requiring pre-trial abstinence do not impact the likelihood of a significant medication effect in the trial.

Effects of ibudilast on central and peripheral markers of inflammation in alcohol use disorder: A randomized clinical trial.

Ibudilast, a neuroimmune modulator, shows promise as a pharmacotherapy for alcohol use disorder (AUD). In vivo administration of ibudilast reduces the expression of pro-inflammatory cytokines in animal models, but its effects on markers of inflammation in humans are unknown. This preliminary study examined the effect of ibudilast on peripheral and potential central markers of inflammation in individuals with AUD. This study also explored the predictive relationship of neurometabolite markers with subsequent drinking in the trial. Non-treatment-seeking individuals with an AUD (n = 52) were randomized to receive oral ibudilast (n = 24) or placebo (n = 28) for 2 weeks. Plasma levels of peripheral inflammatory markers were measured at baseline and after 1 and 2 weeks of medication. At study mid-point, proton magnetic resonance spectroscopy was performed to measure potential neurometabolite markers of inflammation: choline-compounds (Cho), myo-inositol (MI) and creatine + phosphocreatine (Cr) in frontal and cingulate cortices from 43 participants (ibudilast: n = 20; placebo: n = 23). The treatment groups were compared on peripheral and central markers. Ibudilast-treated participants had lower Cho in superior frontal white matter and nominally lower MI in pregenual anterior cingulate cortex. Ibudilast-treated participants had nominally lower C-reactive protein levels at visit 2 and nominally lower TNF-α/IL-10 ratios, relative to placebo. C-reactive protein and Cho levels were correlated, controlling for medication. Superior frontal white matter Cho predicted drinking in the following week. Micro-longitudinal ibudilast treatment may induce peripheral and putative central anti-inflammatory responses in patients with AUD. The neurometabolite responses may be associated with reduction in drinking, suggesting an anti-inflammatory component to the therapeutic action of ibudilast.

Immune treatments for alcohol use disorder: A translational framework.

While the immune system is essential for survival, an excessive or prolonged inflammatory response, such as that resulting from sustained heavy alcohol use, can damage the host and contribute to psychiatric disorders. A growing body of literature indicates that the immune system plays a critical role in the development and maintenance of alcohol use disorder (AUD). As such, there is enthusiasm for treatments that can restore healthy levels of inflammation as a mechanism to reduce drinking and promote recovery. In this qualitative literature review, we provide a conceptual rationale for immune therapies and discuss progress in medications development for AUD focused on the immune system as a treatment target. This review is organized into sections based on primary signaling pathways targeted by the candidate therapies, namely: (a) toll-like receptors, (b) phosphodiesterase inhibitors, (c) peroxisome proliferator-activated receptors, (d) microglia and astrocytes, (e) other immune pharmacotherapies, and (f) behavioral therapies. As relevant within each section, we examine the basic biological mechanisms of each class of therapy and evaluate preclinical research testing the role of the therapy on mitigating alcohol-related behaviors in animal models. To the extent available, translational findings are reviewed with discussion of completed and ongoing randomized clinical trials and their findings to date. An applied and clinically focused approach is taken to identify the potential clinical applications of the various treatments reviewed. We conclude by delineating the most promising candidate treatments and discussing future directions by considering opportunities for immune treatment development and personalized medicine for AUD.

Alcohol use disorder severity moderates clinical response to varenicline.

BACKGROUND: In a multisite clinical trial, varenicline was effective in reducing drinking in both smoking and non-smoking patients with alcohol dependence. Because alcohol use disorder (AUD) is heterogeneous, research aimed at characterizing features associated with treatment response could advance personalized pharmacotherapy. The current study examined the utility of a multidimensional assessment of AUD severity to identify responders to varenicline treatment. METHODS: The study utilized data from a 13-week, Phase 2, randomized, double-blind, placebo-controlled, multisite trial of varenicline in 200 alcohol-dependent patients. Four hypothesized measures of AUD severity (i.e., DSM-IV criterion count, withdrawal, craving, and alcohol-related consequences) were combined into a single severity factor. A series of multilevel models that included the severity factor were conducted to examine its effects on treatment outcomes. RESULTS: All hypothesized indices of AUD severity loaded significantly onto a singular severity factor. Among low-severity groups, varenicline treatment significantly reduced drinking (i.e., percent heavy drinking days, drinks per day, and drinks per drinking day) and, in the lowest severity group, it improved the mental health component of quality of life more than placebo. The most severe group showed no differences between the varenicline and placebo groups on drinking or quality of life measures. CONCLUSIONS: Treatment response to varenicline may be greater among individuals with less-severe AUD, as evidenced by both reductions in drinking outcomes and improvements in psychosocial functioning.

Ibudilast attenuates alcohol cue-elicited frontostriatal functional connectivity in alcohol use disorder.

BACKGROUND: Ibudilast, a novel neuroimmune modulator being studied to treat alcohol use disorder (AUD), was shown in a randomized controlled trial (NCT03489850) to reduce ventral striatum (VS) activation in response to visual alcohol cues. The present study extended this finding by probing the effects of ibudilast on alcohol cue-elicited functional connectivity (i.e., temporally correlated activation) with the VS seed. The study also tests the association between functional connectivity and alcohol use during the trial. METHODS: Non-treatment-seeking participants (n = 45) with current alcohol use disorder were randomized to receive twice-daily dosing with either ibudilast (50 mg; n = 20) or placebo (n = 25). Upon reaching the target dosagee of the medication or placebo, participants completed a functional neuroimaging alcohol cue reactivity paradigm. Drinks per drinking day were assessed at baseline and daily during the 2-week trial. RESULTS: Ibudilast reduced alcohol cue-elicited functional connectivity between the VS seed and reward-processing regions including the orbitofrontal and anterior cingulate cortices compared with placebo (p < 0.05). Cue-elicited functional connectivity was correlated with drinks per drinking day (R2  = 0.5351, p < 0.001), and ibudilast reduced this association in similar reward-processing regions compared with placebo. CONCLUSIONS: Ibudilast's effects on drinking outcomes may be related to the attenuation of functional connectivity in frontostriatal circuits related to reward processing. These results provide an important proof of concept for this novel pharmacotherapy and support the clinical utility of incorporating neuroimaging-and especially functional connectivity-analyses into medication development.

Clinical and Neural Correlates of Reward and Relief Drinking.

BACKGROUND: Alcohol use disorder (AUD) is heterogenous. One approach to parsing this heterogeneity is to phenotype individuals by their underlying motivation to drink, specifically drinking for reward (i.e., positive reinforcement) or for relief (i.e., negative reinforcement/normalizing). Reward- versus relief-motivated behavior is thought to be associated with a shift from ventral to dorsal striatal (DS) signaling. The present study examined whether reward and relief drinking were differentially associated with other clinical characteristics and with alcohol cue-elicited activation of the ventral and dorsal striatum. METHODS: Non-treatment-seeking heavy drinkers (N = 184; 61 female, 123 male) completed the UCLA Reward, Relief, Habit Drinking Scale (RRHDS) and the Reasons for Heavy Drinking Questionnaire (RHDQ), to categorize drinking motivation. Measures of alcohol use, alcohol problems, mood, and craving were also collected. A subset of participants (N = 45; 17 female, 28 male) also completed a functional neuroimaging alcohol cue reactivity task. RESULTS: RRHDS-designated relief/habit drinkers scored lower than reward drinkers on the RHDQ Reinforcement subscale (p = 0.04) and higher on the RHDQ Normalizing subscale (p = 0.004). Relief/habit drinkers also demonstrated greater AUD severity on a host of clinical measures. Relief/habit drinkers displayed higher cue-elicited DS activation compared with reward drinkers (p = 0.04), while ventral striatal cue-elicited activation did not significantly differ between groups. CONCLUSIONS: Our findings support and extend the differentiation of reward from relief/habit-motivated drinking and suggest that differences in DS response to conditioned alcohol cues may underlie this distinction. Elucidating neurobiological and clinical differences between these subtypes may facilitate treatment matching and precision medicine for AUD.

A meta-regression of methodological features that predict the effects of medications on the subjective response to alcohol.

BACKGROUND: Alcohol administration paradigms have been used for early efficacy testing of novel compounds for alcohol use disorder (AUD). There has been an ongoing debate about sample characteristics and methodological features that affect the likelihood of detecting an early efficacy signal for AUD medications. We conducted a meta-regression to test whether the drinking level of the study sample and the peak breath alcohol concentration (BrAC) in the alcohol administration study predict the efficacy of AUD pharmacotherapies on the subjective responses to alcohol. METHODS: We computed the effects of 21 medications on alcohol-induced stimulation, sedation, negative mood, and craving during alcohol administration in 49 studies. RESULTS: Meta-regression analyses indicated a significant and positive effect of pre-study drinks per month on alcohol-induced stimulation (ß = 0.142, p < 0.0001), such that as drinking increases, the benefit of medication over placebo decreases. There was an effect of drinks per month on negative mood (ß = -0.164, p = 0.0248), such that at higher levels of drinks per month, the effects of medications on negative mood are stronger. For sedation, there was an effect of peak BrAC (ß = 0.119, p = 0.0002), such that at low levels of peak BrAC, the effects of medication on sedation were null. For craving, there was a peak BrAC × drinks per month interaction such that at low levels of BrAC, a heavier drinking sample is required to detect the effects of medication on craving. Sensitivity analyses comparing naltrexone studies and non-naltrexone studies suggested that naltrexone was less sensitive to drinks per month across subjective response domains. CONCLUSIONS: These analyses show that design features are critical in studies that test the effects of medications on the subjective responses to alcohol. By specifying the significance and directionality of these effects, as well as the specific points in BrAC or drinks per month at which medication effects are detectable, the study offers recommendations for design features of alcohol administration studies that aim to inform AUD medication development.

Behavioral Economic Demand for Alcohol and Cigarettes in Heavy Drinking Smokers: Evidence of Asymmetric Cross-commodity Reinforcing Value.

INTRODUCTION: Previous studies have highlighted a strong bidirectional relationship between cigarette and alcohol consumption. To advance our understanding of this relationship the present study uses a behavioral economic approach in a community sample (N = 383) of nontreatment seeking heavy drinking smokers. AIMS AND METHODS: The aims were to examine same-substance and cross-substance relationships between alcohol and cigarette use, and latent factors of demand. A community sample of nontreatment seeking heavy drinking smokers completed an in-person assessment battery including measures of alcohol and tobacco use as well as the Cigarette Purchase Task and the Alcohol Purchase Task. Latent factors of demand were derived from these hypothetical purchase tasks. RESULTS: Results revealed a positive correlation between paired alcohol and cigarette demand indices (eg, correlation between alcohol intensity and cigarette intensity) (rs = 0.18-0.46, p ≤ .003). Over and above alcohol factors, cigarette use variables (eg, Fagerström Test for Nicotine Dependence and cigarettes per smoking day) significantly predicted an additional 4.5% (p < .01) of the variance in Persistence values but not Amplitude values for alcohol. Over and above cigarette factors, alcohol use variables predicted cigarette Persistence values (ΔR2 = .013, p = .05), however, did not predict Amplitude values. CONCLUSIONS: These results advance our understanding of the overlap between cigarette and alcohol by demonstrating that involvement with one substance was associated with demand for the other substance. This asymmetric profile-from smoking to alcohol demand, but not vice versa-suggests that it is not simply tapping into a generally higher reward sensitivity and warrants further investigation. IMPLICATIONS: To our knowledge, no study to date has examined alcohol and cigarette demand, via hypothetical purchase tasks, in a clinical sample of heavy drinking smokers. This study demonstrates that behavioral economic indices may be sensitive to cross-substance relationships and specifically that such relationships are asymmetrically stronger for smoking variables affecting alcohol demand, not the other way around.