Reactivity of alcoholics and nonalcoholics to drinking cues

Positive mental imagery, emotion regulation and depressive symptoms in individuals with alcohol use disorder

Introductions

Emotion regulation, depressive symptoms and mental imagery have both been linked to alcohol use disorder (AUD). However, the association between these factors have not been investigated within a group of individuals with AUD.

Objectives

The primary aim of this study was to investigate associations between emotion regulation, depressive symptoms and positive mental imagery among individuals with AUD and healthy controls (HCs).

Methods

The study sample included 136 individuals with AUD and 80 HCs. Severity of depressive symptoms was assessed with the Beck Depression Inventory (BDI) and emotion dysregulation - with the Difficulties in Emotion Regulation Scale (DERS). The Flexible Emotion Regulation Scale (FlexER) was used to measure flexible emotion regulation and the Prospective Imagery Task (PIT) - to assess positive mental imagery.

Results

Vividness of positive mental imagery was significantly lower in the AUD group compared to HC group, while emotional intensity of positive mental imagery was significantly higher in the AUD group. Higher vividness of positive mental imagery was associated with lower emotional dysregulation in the AUD group and with higher flexibility of emotion regulation among both groups. Emotional intensity of positive mental imagery was positively correlated with flexibility of emotion regulation in the AUD group, but negatively correlated with flexibility of emotion regulation among HCs. In the AUD group, both vividness and emotional intensity of positive mental imagery were significantly associated with lower severity of depressive symptoms.

Conclusions

Enhancing positive mental imagery abilities might be a promising strategy in the treatment of AUD.

Intranasal oxytocin blunts amygdala response to negative affective stimuli in males and females with alcohol use disorder: a randomized controlled cross-over trial

RATIONALE

Negative affect plays a prominent role in the maintenance of alcohol use disorder (AUD) and has been identified as a risk factor for relapse to alcohol. To date, however, treatment options that target negative affective states and consecutive relapse risk in AUD are insufficient. Oxytocin (OXY) might be a promising approach for addressing negative affective states and resulting motivation to use alcohol.

OBJECTIVES

We aimed to investigate the acute effects of 24 I.U. OXY, administered intranasally, compared to matched placebo (PLC) on central processing of negative emotional stimuli in the amygdala in individuals with AUD.

METHODS

We conducted a randomized double-blind placebo-controlled crossover study in N = 24 individuals with AUD. Amygdala response to emotional stimuli served as primary outcome and was assessed using a validated functional magnetic resonance imaging emotion-processing task. Alcohol craving served as secondary outcome.

RESULTS

OXY versus PLC attenuated right amygdala reactivity to fearful and angry emotional face stimuli during the fMRI task (t(33) = 3.32, pFWE=0.035), while no effect of OXY on amygdala activation was observed during the presentation of geometric figures. In addition, right amygdala reactivity to fearful and angry emotional face stimuli was positively associated with alcohol craving (r =.332, Bias corrected and accelerated 95% confidence interval [95% BCa CI]=-0.044 to 0.624, p =.042).

CONCLUSIONS

OXY's effects on the neurocircuitry underlying negative affect and craving in AUD support its potential for dampening alcohol craving induced by negative affective states and implicate OXY as a potential future treatment option for AUD.

CLINICALTRIALS REGISTRY

DRKS00026218.

Alcohol and cannabis co-use: Probing subjective response in eliciting cross-substance craving

The co-use of alcohol and cannabis is rising in prevalence, yet the mechanisms driving individuals to co-use are not well understood. Subjective response to alcohol or cannabis may predict the desire to use either substance. However, which specific facets of subjective response predict cross-substance craving remains unclear. The present study investigated whether acute administration of alcohol or cannabis facilitates cue-induced craving for the other substance, with an emphasis on the underlying subjective response mechanisms contributing to co-use. This is a secondary analysis of a behavioral pharmacology study that combined alcohol/cannabis administration with a cross-substance cue-reactivity paradigm in individuals who were heavy alcohol and heavy cannabis co-users. Over two sessions, twenty-nine individuals (17M/12F) self-administered alcohol or cannabis (in a crossover design), and then completed a cue-reactivity exercise with the other substance. Analyses tested how changes in subjective response variables following substance administration predicted cross-substance cue-induced craving. Following alcohol administration, greater subjective ratings of positive mood predicted significantly greater cue-induced cannabis craving (β = 1.14, SE = 0.41, t = 2.80, p = 0.010). Following cannabis administration, lower subjective effects ratings of positive mood/arousal predicted significantly greater cue-induced alcohol craving (β = -1.08, SE = 0.38, t = -2.85, p = 0.009; β = -2.38, SE = 1.13, t = -2.10, p = 0.047). This study identified subject response mechanisms contributing to cross-substance cue induced craving. These mechanisms include increases in positive mood following alcohol use and decreases in positive mood and arousal, akin to increases in relaxation, following cannabis use.

A cue reactivity experiment: Exposure to images of alcoholic beverages and social contexts on alcohol cravings, motivations, attitudes, approval, and behavior

The incentive-sensitization theory of addiction postulates that relevant cues can trigger alcohol cravings, tendencies, and related outcomes. Additionally, consistent with the encoding specificity principle and social impact theory, social contexts depicting people can activate pro-alcohol reactions and tendencies. This randomized experiment tested the cue reactivity effects of exposure to images depicting variations in the number of people consuming alcoholic or nonalcoholic beverages on alcohol-related cravings and outcomes. The sample consisted of 594 adult alcohol users who passed manipulation checks. Participants were randomly assigned to a condition in a 2 (beverage type cue manipulation: alcoholic vs. nonalcoholic) × 3 (social context cue manipulation: beverage-only [no people] vs. solitary drinking [1 person] vs. social drinking [2 or more people]) factorial design and primed with a series of photographs. Dependent variables measured alcohol cravings, alcohol motives, alcohol attitudes, alcohol approval, and alcohol behavior. Factorial MANCOVA and ANCOVAs were performed. Main effects for the social context manipulation were found. Specifically, the social drinking condition compared to the beverage-only condition induced significantly higher pro-alcohol cravings, attitudes, and behaviors. The beverage type manipulation did not influence the dependent variables. The findings offer insights that visual cues depicting social drinking scenarios activated alcohol-related cravings and outcomes, regardless of whether the beverages shown were alcoholic or nonalcoholic. This priming experiment helps to understand the social mechanisms underlying cue reactivity and offers implications for advancing cue-based alcohol interventions.

Examining the Impact of Simultaneous Alcohol and Cannabis Use on Alcohol Consumption and Consequences: Protocol for an Observational Ambulatory Assessment Study in Young Adults

BACKGROUND

There is significant conflicting evidence as to how using cannabis while drinking alcohol (ie, simultaneous alcohol and cannabis use) impacts alcohol volume consumed, patterns of drinking, and alcohol-related consequences. The impact of simultaneous use on drinking outcomes may be influenced by several within-person (eg, contextual) and between-person (individual) factors.

OBJECTIVE

This study was designed to examine naturalistic patterns of alcohol and cannabis use to understand how simultaneous use may impact drinking outcomes. The primary aims were to understand the following: (1) if simultaneous use is associated with increased alcohol consumption and riskier patterns of drinking, (2) if simultaneous use leads to increased alcohol consequences, and (3) how contextual circumstances moderate the impact of simultaneous use on consumption and consequences.

METHODS

Data collection involves a 28-day ambulatory assessment protocol in which a sample of non-treatment-seeking young adults who report simultaneous use of alcohol and cannabis complete ecological momentary assessments (random, event-contingent, and time-contingent surveys) of alcohol and cannabis use, contexts, motives, and consequences on their personal smartphones while continuously wearing an alcohol biosensor bracelet. Participants also complete a baseline assessment, brief internet-based check-in on day 14, and a final session on day 28. Community-based recruitment strategies (eg, social media and flyers) were used to enroll 95 participants to obtain a target sample of 80, accounting for attrition.

RESULTS

Recruitment and data collection began in May 2021 and continued through June 2024. Initial results for primary aims are expected in October 2024. As of March 2024, the project had recruited 118 eligible participants, of whom 94 (79.7%) completed the study, exceeding initial projections for the study time frame. Remaining recruitment will provide the capacity to probe cross-level interactions that were not initially statistically powered. Strengths of the project include rigorous data collection, good retention and compliance rates, faster-than-expected enrollment procedures, use of a novel alcohol biosensor, and successful adaptation of recruitment and data collection procedures during the COVID-19 pandemic.

CONCLUSIONS

This is the first investigation to assess the key momentary predictors and outcomes of simultaneous use as well as self-reported and objective (via alcohol biosensor) measures of alcohol consumption and patterns. The results of this study will inform prevention efforts and studies of individuals who use cannabis who are engaged in alcohol treatment.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/58685.

Characterizing alcohol cue reactive and non-reactive individuals with alcohol use disorder

PURPOSE

Exposure to alcohol-related cues is thought to elicit a conditional response characterized by increased craving in individuals with alcohol use disorder (AUD). In the context of AUD research, it is important to consider that not all individuals with an AUD are alcohol cue reactive. This study systematically examined subjective alcohol cue reactivity and its clinical and drinking correlates in individuals with an AUD enrolled in a human laboratory pharmacotherapy trial.

METHODS

Individuals with current moderate-to-severe AUD (N = 52) completed a standard alcohol cue exposure paradigm and individual difference assessments as part of a human laboratory pharmacotherapy trial (NCT04249882). We classified participants as cue reactive (CR+) and cue non-reactive (CR-), as indicated by self-reported, subjective alcohol urge, and examined group differences in baseline clinical characteristics and drinking outcomes over the course of the trial.

RESULTS

Twenty participants (38%) were identified as CR+, while 32 participants (62%) were identified as CR-. The CR+ and CR- groups did not differ in baseline drinking and AUD clinical characteristics, but the groups differed in race composition (p = 0.02) and smoking prevalence (p = 0.04) such that the CR+ group had lower prevalence of smokers. The CR+, compared with the CR-, group drank more during the trial titration period (p = 0.03). Both groups reduced drinking across the trial (p's < 0.001), but the CR+ group exhibited a smaller reduction in drinking, compared with the CR- group (time x group, p = 0.029; CR-, p < 0.0001; CR+: p = 0.01).

CONCLUSION

Results indicate that cue reactivity is a heterogenous construct. Recognizing this heterogeneity, and the clinical factors associated with it, is critical to advancing this paradigm as an early efficacy marker in AUD research.

Leveraging meta-regression to test if medication effects on cue-induced craving are associated with clinical efficacy

RATIONALE

The alcohol cue exposure paradigm is a common method for evaluating new treatments for alcohol use disorder (AUD); however, it is unclear if medication-related reductions in cue-induced craving in the human laboratory can predict the clinical success of those medications in reducing alcohol consumption during clinical trials.

OBJECTIVES

To use a novel meta-analytic approach to test whether medication effect sizes on cue-induced alcohol craving are associated with clinical efficacy in clinical trials.

METHOD

We searched the literature for medications tested for AUD treatment using both the alcohol cue-reactivity paradigm and randomized clinical trials (RCTs). For alcohol cue-reactivity studies, we computed medication effect sizes for cue-induced alcohol craving (k = 36 studies, 15 medications). For RCTs, we calculated medication effect sizes for heavy drinking and abstinence (k = 139 studies, 19 medications). Using medication as the unit of analysis, we applied the Williamson-York bivariate weighted least squares estimation to account for errors in both independent and dependent variables. We also conducted leave-one-out cross validation simulations to examine the predictive utility of cue-craving medication effect sizes on RCT heavy drinking and abstinence endpoints.

RESULTS

There was no significant relationship between medication effects on cue-induced alcohol craving in the human laboratory and medication effects on heavy drinking ( β ^ = 0.253, SE = 0.189, p = 0.090) and abstinence ( β ^ = 0.829, SE = 0.747, p = 0.133) in RCTs.

CONCLUSIONS

The preliminary results of the current study challenge the assumption that alcohol cue-reactivity alone can be used as an early efficacy indicator for AUD pharmacotherapy development. These findings suggest that a wider range of early efficacy indicators and experimental paradigms be considered for Phase II testing of novel compounds.

Neural correlates of increased alcohol demand following alcohol cue exposure in adult heavy drinkers

Alcohol use disorder is associated with overvaluation of alcohol relative to other rewards, in part due to dynamic increases in value in response to alcohol-related cues. In a neuroeconomic framework, alcohol cues increase behavioral economic demand for alcohol, but the neural correlates these cue effects are unknown. This functional magnetic resonance imaging study combined a neuroeconomic alcohol purchase task with an alcohol cue exposure in 72 heavy drinkers with established sensitivity to alcohol cues (51 % female; mean age=33.74). Participants reported how many drinks they would consume from $0-$80/drink following exposure to neutral and alcohol images in a fixed order. Participants purchased significantly more drinks in the alcohol compared to the neutral condition, which was also evident for demand indices (i.e., intensity, breakpoint, Omax, elasticity; ps<0.001; ds=0.46-0.92). Alcohol purchase decisions were associated with activation in rostral middle and medial frontal gyri, anterior insula, posterior parietal cortex, and dorsal striatum, among other regions. Activation was lower across regions in the alcohol relative to neutral cue condition, potentially due to greater automaticity of choices in the presence of alcohol cues or attenuation of responses due to fixed cue order. These results contribute to growing literature using neuroeconomics to understand alcohol misuse and provide a foundation for future research investigating decision-making effects of environmental alcohol triggers.

Alcohol-associated liver disease and behavioral and medical cofactors: unmet needs and opportunities

Chronic liver disease is a leading cause of death in the US and is often preventable. Rising burden, cost, and fatality due to liver disease are driven by intensified alcohol use in the US population and the contributions of comorbid conditions. This mini-review focuses on the topic of liver health in the context of chronic, behavioral cofactors of disease, using research-based examples from the Brown University Center for Addiction and Disease Risk Exacerbation (CADRE). Our aim is to illustrate the current challenges and opportunities in clinical research addressing liver health in the context of behavioral and medical comorbidity and to highlight next steps in this crucial area of public health research and clinical care.

Anterior cingulate and medial prefrontal cortex alcohol cue reactivity varies as a function of drink preference in alcohol use disorder

BACKGROUND

Functional MRI visual cue reactivity studies have not considered that brain responses to various alcohol-containing beverage types may vary as a function of an individual's drinking patterns and preferences. This study tested whether the brain's reward system responds differently to visual cues associated with an individuals' most commonly consumed ("preferred") alcohol beverage compared with less commonly consumed ("non-preferred") alcohol beverages in individuals with alcohol use disorder (AUD).

METHODS

Participants (N=70) with current AUD completed a standard visual alcohol cue reactivity procedure during fMRI and reported recent alcohol use through the Timeline Followback interview. Alcohol use patterns were used to infer drink preference. Repeated measure ANCOVAs were used to evaluate differences in subjective craving (alcohol urge) and neural reactivity to cues of individual's "preferred" versus "non-preferred" alcohol beverages.

RESULTS

Fifty-four (77%) participants were determined to have a "preferred" alcohol beverage, as defined by their pattern of alcohol use. These participants reported greater subjective alcohol urge (p=0.02) and activation in the anterior cingulate cortex (ACC) (p=0.005) and medial prefrontal cortex (mPFC) (p=0.001)) in response to visual cues associated with their "preferred" versus "non-preferred" alcohol beverage. Individuals with an alcohol preference did not differ from those with no alcohol preference on subjective or neural responses to their "preferred" and "non-preferred" alcohol cues.

DISCUSSION

Results suggest alcohol cue-elicited subjective and neural responses vary as a function of alcohol beverage preference in individuals with AUD and a behaviorally defined alcohol preference. Stronger ACC and mPFC activation may reflect greater subjective value of an individual's "preferred" alcohol beverage cue.

A practice quit model to test early efficacy of medications for alcohol use disorder in a randomized clinical trial

RATIONALE

Screening novel medications for alcohol use disorder (AUD) requires models that are both efficient and ecologically-valid. Ideally, such models would be associated with the outcomes of a given medication in clinical trials.

OBJECTIVES

To test a novel human laboratory model in which individuals with intrinsic motivation to change their drinking engage in a "practice quit" attempt consisting of 6 days of complete abstinence from alcohol.

METHOD

Individuals with current AUD completed a randomized, double-blind, placebo-controlled study of naltrexone (50 mg), varenicline (2 mg bid), or matched placebo. Participants were titrated onto the study medication for 1 week prior to starting the 6-day practice quit attempt. During the practice quit attempt, participants completed daily interviews with research staff. All participants completed an alcohol cue-exposure paradigm before starting the study medication and after 2 weeks of study medication.

RESULTS

There were no significant medication effect on drinks per drinking day (F(2,49) = 0.66, p = 0.52) or percent days abstinent (F(2,49) = 0.14, p = 0.87) during the 6-day practice quit period. There were no medication effects on alcohol cue-reactivity (F(2,44) = 0.80, p = 0.46). Notably, participants sharply reduced their drinking during the entire 13-day medication treatment period, as compared to reducing only during the 6-day practice quit period. During the total medication period, higher levels of motivation to change was associated with higher percent days abstinent (F(1,49) = 8.12, p < 0.01).

CONCLUSIONS

This study reports mostly null findings, which challenges us to decompose its nuanced design to consider model refinements. Possible changes to the model include considering the requirement for intrinsic motivation for change, including a longer practice quit period, encompassing the medication administration timeframe in the practice quit period, increasing the required sample size for signal detection, and examining a post COVID-19 pandemic cohort.

Alcohol cues increase behavioral economic demand and craving for alcohol in nontreatment-seeking and treatment-seeking heavy drinkers

BACKGROUND

Behavioral economic research has revealed significant increases in alcohol demand following exposure to alcohol-related cues. Prior research has focused exclusively on nontreatment-seeking heavy drinkers, included only male participants, or used heterogeneous methods. The current studies sought to replicate and extend existing findings in treatment-seeking and nontreatment-seeking heavy drinkers while also examining sex effects and moderation by alcohol use disorder (AUD) severity.

METHODS

Study 1 included 117 nontreatment-seeking heavy drinkers (51.5% women; M age 34.69; 56.4% AUD+), and Study 2 included 89 treatment-seeking heavy drinkers with AUD (40.4% women; M age = 41.35). In both studies, alcohol demand was measured using a hypothetical alcohol purchase task (APT), and subjective alcohol craving was measured using visual analog scales. Measures were collected following exposure to neutral (water) cues in a standard room and alcohol cues in a bar lab.

RESULTS

Alcohol demand (intensity, Omax , breakpoint, and elasticity) and craving were significantly increased following alcohol cues compared to neutral cues (ps < 0.005) with effect sizes ranging from small to large (ηp 2  = 0.074-0.480). Participants with AUD (Study 1) or with higher AUD severity (Study 2) reported higher craving and higher demand for most indices (i.e., main effects; ps < 0.032, ηp 2  = 0.043-0.239). A larger alcohol cue increase in Omax was found for AUD+ participants in Study 1 compared to non-AUD participants (p = 0.028, ηp 2  = 0.041) but not for any other indices in Study 1 or Study 2. There were no significant sex effects.

CONCLUSIONS

These findings replicate and extend prior research by offering additional insight into alcohol cue effects on the reinforcing value of alcohol and subjective motivation to drink. The results also suggest that sex and AUD severity do not meaningfully impact cue effects across most indices of demand.

Testing pharmacotherapies for alcohol use disorder with cue exposure paradigms: A systematic review and quantitative synthesis of human laboratory trial methodology

Alcohol cue exposure is a widely used experimental paradigm for screening pharmacotherapies for alcohol use disorder (AUD). Medication-related reductions in cue-reactivity signal early efficacy and inform medications development. Yet, across trials, the design of cue exposure, parameter testing, and outcome reporting is heterogeneous. This systematic review is a quantitative synthesis of trial methodologies and effect size estimation for AUD medication-related craving and psychophysiological outcomes under the cue exposure paradigm. A PubMed search was conducted on January 3, 2022 based on identified pharmacotherapies for peer-reviewed articles reported in English. Study-level characteristics, including sample descriptors, paradigm design, analytic approach, and Cochrane Risk of Bias, along with descriptive statistics for cue-exposure outcomes, were coded by two independent raters. Study-level effect sizes were estimated for craving and psychophysiological outcomes separately and sample-level effect sizes were calculated for each medication. Thirty-six trials, comprising 1640 participants and testing 19 different medications satisfied eligibility criteria. All studies reported on biological sex (71% male participants on average). The exposure paradigms implemented used in vivo (n = 26), visual (n = 8), and audio script (n = 2) cues. Some trials included means for craving by medication condition in text (k = 7) or figures (k = 18). The quantitative synthesis included 63 effect sizes (craving kes  = 47; psychophysiological kes  = 16) from 28 unique randomized trials testing 15 medications for effects on cue reactivity. For cue-induced craving, eight medications (kes range: 1-12) demonstrated small-to-medium effects (Cohen's d range: |0.24-0.64|) compared to placebo, with individuals randomized to receive medication reporting lower craving following cue exposure. Recommendations are provided to promote further consilience, so that the utility of cue exposure paradigms can be maximized in the development of effective AUD pharmacotherapies. Future work should explore the predictive utility of medication-related reductions in cue-reactivity on clinical outcomes.

Psilocybin prevents reinstatement of alcohol seeking by disrupting the reconsolidation of alcohol-related memories

BACKGROUND

For most psychiatric conditions, including alcohol use disorder (AUD), FDA-approved pharmacological treatments are limited and their efficacy is restricted to only certain subgroups of patients. Scientific interest in the potential of psychedelic drugs has dramatically increased because of clinical preliminary evidence of efficacy in treating various psychiatric disorders. One of the most promising compounds belonging to this class of molecules is psilocybin. Here, to elucidate the therapeutic potential and treatment modalities of this drug, we investigated the effect of psilocybin on alcohol drinking and seeking in genetically selected Marchigian Sardinian alcohol-preferring (msP) rats, a well validated animal model of AUD characterized by excessive drinking and seeking.

METHODS

Using male and female msP rats, we tested the effect of psilocybin on home cage voluntary alcohol consumption. We also tested the effect of the drug on the alcohol deprivation effect (ADE) model of relapse and on cue-induced reinstatement of alcohol seeking after a period of abstinence. Finally, we evaluated if psilocybin may disrupt the reconsolidation process of alcohol-related memory.

RESULTS

Psilocybin did not reduce alcohol consumption, nor it prevented increased alcohol drinking after a period of forced abstinence and cue-induced reinstatement of alcohol-seeking. Noteworthy, in a memory retrieval-reconsolidation paradigm, psilocybin markedly attenuated resumption of alcohol seeking.

CONCLUSIONS

Altogether these data suggest that, despite psilocybin does not affect alcohol drinking and relapse, it may be highly effective if used to block the reconsolidation process of alcohol-related memories. This opens to the possibility of using this psychedelic drug in clinical settings in which AUD patients undergo procedures to recall the memory of alcohol and are then treated with psilocybin during the memory reconsolidation phase.

β2* nicotinic acetylcholine receptor subtypes mediate nicotine-induced enhancement of Pavlovian conditioned responding to an alcohol cue

Nicotine enhances Pavlovian conditioned responses to reward-associated cues. We investigated through which nicotinic acetylcholine receptor (nAChR) subtypes nicotine acts to produce this behavioral effect to an alcohol-associated cue. Male Long-Evans rats with freely available food and water were first accustomed to drinking 15% ethanol in their home cages using an intermittent access, two-bottle choice procedure. Then the rats were given 15 Pavlovian conditioning sessions in which a 15-s audiovisual conditioned stimulus (CS) predicted the delivery of 0.2 ml of ethanol, the unconditioned stimulus (US). Each session contained 12 CS-US trials. A control group received explicitly unpaired presentations of the CS and US. We measured Pavlovian conditioned approach to the site of US delivery during presentations of the CS, accounting for pre-CS baseline activity. Before each conditioning session, rats were injected subcutaneously with nicotine (0.4 mg/kg) or saline (1 ml/kg). During nAChR antagonist test sessions, rats were first injected systemically with the β2*-selective nAChR antagonist dihydro-beta-erythroidine (DHβE; 3 mg/kg) or the α7-selective nAChR antagonist methyllycaconitine (MLA; 6 mg/kg), followed by their assigned nicotine or saline injection before assessing their conditioned response to the alcohol-associated cue. Consistent with previous reports, nicotine enhanced the Pavlovian conditioned response to the alcohol-paired cue. DHβE attenuated this enhancement, whereas MLA did not. These results suggest that nicotine acts via β2*, but not α7, nAChRs to amplify Pavlovian conditioned responding to an alcohol cue. These findings contribute to a growing literature that identifies nAChRs as potential targets for pharmacological treatment of co-morbid alcohol and tobacco use disorders.

Ibudilast moderates the effect of mood on alcohol craving during stress exposure

Neuroinflammation is implicated in the development and maintenance of alcohol use disorder (AUD) and neuroimmune therapeutics show promise in treating AUD. Proinflammatory signaling contributes to progressive elevations in the dysfunction of mood and alcohol craving. The current study sought to examine potential biobehavioral mechanisms of neuroimmune modulation in AUD under experimental conditions. In a community sample of individuals with AUD who completed a placebo-controlled crossover trial of ibudilast, we tested the effect of ibudilast on the relationship between mood states and alcohol craving. Multilevel modeling analyses tested the hypothesis that ibudilast would moderate the effect of positive and negative mood states on alcohol craving during stress and cue exposures. Results revealed that after stress-induction, participants' feelings of depression and happiness were more strongly predictive of their craving for alcohol while taking ibudilast as compared with placebo (ps < .03). These results suggest that with neuroimmune modulation, positive and negative mood states may have a stronger influence on one's desire to drink, such that craving may be more mood dependent. No moderating effect of ibudilast on mood states and craving were observed after alcohol cue exposure. Given the potential of anti-inflammatory treatments to reduce depressive symptomatology, this strengthened relationship between mood and craving under ibudilast might reduce the likelihood of stress-related craving and subsequent drinking over time. Moreover, ibudilast may enhance the benefits of happiness, such that maintaining positive mood in the face of acute stress may attenuate craving. Future trials directly testing the clinical implications of these mechanistic findings are warranted. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A randomized controlled trial examining the effects of intranasal oxytocin on alcohol craving and intimate partner aggression among couples

BACKGROUND

While alcohol use disorder (AUD) is a well-established risk factor for intimate partner aggression (IPA), effective treatments for co-occurring AUD and IPA (AUD/IPA) are lacking. Oxytocin is one promising pharmacological candidate for AUD/IPA given its potential to modulate social behavior and attenuate alcohol use. However, emerging data suggests that oxytocin's prosocial effects are inconsistent, and a small number of studies have also found that oxytocin might have the potential to be aggressogenic. No studies have directly examined the impact of oxytocin on alcohol- or IPA-related outcomes in a dyadic context.

METHODS

The goal of this double-blind, randomized, and placebo-controlled trial was to examine the effects of a single dose of intranasal oxytocin (40 international units) on cue-induced alcohol craving, subjective aggression, laboratory task-based IPA, and cortisol reactivity in a sample of 100 couples (N = 200 individuals) with AUD and physical IPA in their current relationship.

RESULTS

There were no statistically significant differences between the oxytocin and placebo conditions for any of the primary outcomes.

CONCLUSIONS

Findings suggest that a single dose of intranasal oxytocin was not efficacious in mitigating alcohol craving or aggression in this sample. Although hypotheses were not supported, the findings provide important evidence that oxytocin was not aggressogenic in this high-risk sample. Future research investigating dispositional and contextual moderators of oxytocin response in addition to the therapeutic effects of more intensive oxytocin dosing or administration strategies on alcohol craving and aggression is warranted.

Global sleep quality is associated with tonic craving, but not cue-induced craving

OBJECTIVE

Sleep disturbance is widespread among individuals with alcohol use disorder (AUD) and is thought to reduce the capacity for self-regulation. The present study examines how sleep disturbance is associated with the regulation of tonic (i.e., "trait-like") and cue-induced (i.e., "provoked") craving, among individuals with AUD.

METHODS

Participants with an AUD (N = 58) completed the Pittsburgh Sleep Quality Index (PSQI) for sleep quality, the Obsessive-Compulsive Drinking Scale (OCDS) for tonic craving, and the Alcohol Urge Questionnaire (AUQ) for cue-induced craving during an alcohol cue-exposure paradigm. A series of hierarchical regressions examined the independent contribution of sleep quality to tonic and cue-induced alcohol craving.

RESULTS

PSQI global score was associated with tonic craving per the OCDS, over and above alcohol use and demographic measures. PSQI global score was not associated with cue-induced craving.

CONCLUSION

These findings suggest that sleep dysfunction plays a role in tonic alcohol craving and that the underlying mechanism may be the reduction of self-regulation. Treatments targeting sleep dysfunction in AUD may prove useful in reducing craving and overall alcohol use.

How laboratory studies of cigarette craving can inform the experimental alcohol craving literature

Interest in alcohol and other drug craving has flourished over the past two decades, and evidence has accumulated showing that craving can be meaningfully linked to both drug use and relapse. Considerable human experimental alcohol craving research since 2000 has focused on craving as a clinical phenomenon. Self-reported craving to drink typically has served as a catch-all for the craving construct in these studies, whereas few studies have considered craving as a process (or hypothetical construct) that interacts with other phenomena to affect use. In contrast to alcohol, we believe that recently there has been more mechanistic work targeting cigarette craving-related processes. Here, we briefly present a narrative review of studies of acute alcohol craving in humans that have been conducted during the past two decades. We then specify important ways in which alcohol and tobacco differ (e.g., the role of withdrawal), and we note the unique challenges in inducing robust alcohol craving states in the laboratory. Finally, we offer recommendations for how the alcohol field might advance its conceptual understanding of craving by adopting ideas and methods drawn from the smoking research literature. Specifically, we suggest that researchers extend their studies to not only examine the link between alcohol craving and relapse but also to focus on why and, in some instances, how alcohol cravings matter clinically, and the circumstances under which craving especially matters. We propose research to investigate the shifts in alcohol-related cognitive and affective processing that occur during alcohol craving states. Furthermore, we highlight the value of research examining the level of insight that individuals with varying levels of alcohol involvement possess about their own craving-related processing shifts. We believe that laboratory studies can provide rich opportunities to examine conceptual questions about alcohol craving that are central to addiction.

The overexpression of GDNF in nucleus accumbens suppresses alcohol-seeking behavior in group-housed C57Bl/6J female mice

Background

Craving for alcohol, in other words powerful desire to drink after withdrawal, is an important contributor to the development and maintenance of alcoholism. Here, we studied the role of GDNF (glial cell line-derived neurotrophic factor) and BDNF (brain-derived neurotrophic factor) on alcohol-seeking behavior in group-housed female mice.

Methods

We modeled alcohol-seeking behavior in C57Bl/6J female mice. The behavioral experiments in group-housed female mice were performed in an automated IntelliCage system. We conducted RT-qPCR analysis of Gdnf, Bdnf, Manf and Cdnf expression in different areas of the female mouse brain after alcohol drinking conditioning. We injected an adeno-associated virus (AAV) vector expressing human GDNF or BDNF in mouse nucleus accumbens (NAc) after ten days of alcohol drinking conditioning and assessed alcohol-seeking behavior. Behavioral data were analyzed by two-way repeated-measures ANOVA, and statistically significant effects were followed by Bonferroni’s post hoc test. The student’s t-test was used to analyze qPCR data.

Results

The RT-qPCR data showed that Gdnf mRNA level in NAc was more than four times higher (p < 0.0001) in the mice from the sweetened alcohol group compared to the water group. Our data showed a more than a two-fold decrease in Manf mRNA (p = 0.04) and Cdnf mRNA (p = 0.02) levels in the hippocampus and Manf mRNA in the VTA (p = 0.04) after alcohol consumption. Two-fold endogenous overexpression of Gdnf mRNA and lack of CDNF did not affect alcohol-seeking behavior. The AVV-GDNF overexpression in nucleus accumbens suppressed alcohol-seeking behavior while overexpression of BDNF did not.

Conclusions

The effect of increased endogenous Gdnf mRNA level in female mice upon alcohol drinking has remained unknown. Our data suggest that an increase in endogenous GDNF expression upon alcohol drinking occurs in response to the activation of another mesolimbic reward pathway participant.

NOP receptor antagonism attenuates reinstatement of alcohol-seeking through modulation of the mesolimbic circuitry in male and female alcohol-preferring rats

In patients suffering from alcohol use disorder (AUD), stress and environmental stimuli associated with alcohol availability are important triggers of relapse. Activation of the nociceptin opioid peptide (NOP) receptor by its endogenous ligand Nociceptin/Orphanin FQ (N/OFQ) attenuates alcohol drinking and relapse in rodents, suggesting that NOP agonists may be efficacious in treating AUD. Intriguingly, recent data demonstrated that also blockade of NOP receptor reduced alcohol drinking in rodents. To explore further the potential of NOP antagonism, we investigated its effects on the reinstatement of alcohol-seeking elicited by administration of the α2 antagonist yohimbine (1.25 mg/kg, i.p.) or by environmental conditioning factors in male and female genetically selected alcohol-preferring Marchigian Sardinian (msP) rats. The selective NOP receptor antagonist LY2817412 (0.0, 3.0, 10.0, and 30.0 mg/kg) was first tested following oral (p.o.) administration. We then investigated the effects of LY2817412 (1.0, 3.0, 6.0 μg/μl/rat) microinjected into three candidate mesolimbic brain regions: the ventral tegmental area (VTA), the central nucleus of the amygdala (CeA), and the nucleus accumbens (NAc). We found that relapse to alcohol seeking was generally stronger in female than in male rats and oral administration of LY2817412 reduced yohimbine- and cue-induced reinstatement in both sexes. Following site-specific microinjections, LY2817412 reduced yohimbine-induced reinstatement of alcohol-seeking when administered into the VTA and the CeA, but not in the NAc. Cue-induced reinstatement was suppressed only when LY2817412 was microinjected into the VTA. Infusions of LY2817412 into the VTA and the CeA did not alter saccharin self-administration. These results demonstrate that NOP receptor blockade prevents the reinstatement of alcohol-seeking through modulation of mesolimbic system circuitry, providing further evidence of the therapeutic potential of NOP receptor antagonism in AUD.

Exploring regulation and function of dopamine D3 receptors in alcohol use disorder. A PET [11C]-(+)-PHNO study

Preclinical studies support an important role of dopamine D3 receptors (DRD3s) in alcohol use disorder (AUD). In animals, voluntary alcohol consumption increases DRD3 expression, and pharmacological blockade of DRD3s attenuates alcohol self-administration and reinstatement of alcohol seeking. However, these findings have yet to be translated in humans. This study used positron emission tomography (PET) and [11C]-(+)-PHNO to compare receptor levels in several dopamine D2 receptor (DRD2) and DRD3 regions of interest between AUD subjects in early abstinence (n = 17; 6.59 ± 4.14 days of abstinence) and healthy controls (n = 18). We recruited non-treatment seeking subjects meeting DSM-5 criteria for AUD. We examined the relationship between DRD2/3 levels and both alcohol craving and alcohol motivation/wanting, using a cue reactivity procedure and an intravenous alcohol self-administration (IVASA) paradigm, respectively. [11C]-(+)-PHNO binding levels in AUD subjects were significantly lower than binding in HCs when looking at all DRD2/3 ROIs jointly (Wilk's Λ = .58, F(6,28) =3.33, p = 0.013, η2p = 0.42), however there were no region-specific differences. Binding values demonstrate -12.3% and -16.1% lower [11C]-(+)-PHNO binding in the SMST and SN respectively, though these differences did not withstand Bonferroni corrections. There was a positive association between [11C]-(+)-PHNO binding in the SN (almost exclusively reflective of DRD3) and alpha (lower values reflect higher alcohol demand) in the APT after Bonferroni corrections (r = 0.66, p = 0.0080). This demonstrates that AUD subjects with lower DRD3 levels in the SN exhibit increased demand for alcohol. These results replicate previous findings demonstrating reduced DRD2/3 levels while also supporting a lack of DRD3 upregulation and potential downregulation in early abstinent AUD. Furthermore, the finding that binding in the SN is associated with alcohol demand warrants further examination.

Negative affect and alcohol craving in trauma-exposed young adult drinkers

BACKGROUND

Clinical research indicates that successful posttraumatic stress disorder (PTSD) treatment does not lead to improvements in alcohol use outcomes in comorbid PTSD and alcohol use disorder (AUD). Emerging theory suggests that treating PTSD may not disrupt an association between negative affect and alcohol craving, which underlies negative reinforcement drinking. The goal of the current study was to determine the respective influences of PTSD symptoms, coping motives, and negative affect on trauma and alcohol cue reactivity to inform theoretical models of co-occurring PTSD and AUD.

METHODS

The sample consisted of 189 young adults (50.3% women; 49.2% current PTSD; 84.0% current AUD) who endorsed interpersonal trauma (e.g., sexual/physical assault) and current weekly alcohol use. Participants completed a trauma and alcohol cue reactivity assessment, in which subjective (e.g., craving, affect) and physiological (i.e., salivation) measures were recorded in response to 4 narrative (i.e., personalized trauma or standard neutral) and in vivo beverage (i.e., personalized alcohol or water) cue combinations.

RESULTS

Forward-fitted linear mixed-effects (LME) models confirmed that trauma cue-elicited craving was elevated among those high but not low in PTSD symptoms, consistent with prior research and theory. Trauma cue-elicited craving was fully explained by increases in negative affect, with no evidence of a direct effect of trauma cue on craving. PTSD symptoms moderated an association between trauma cue and negative affect (but not negative affect and craving), and coping motives for alcohol moderated an association between negative affect and craving (but not trauma cue and negative affect).

CONCLUSIONS

This study provides novel laboratory evidence for the respective contributions of negative affect, PTSD symptoms, and coping motives on alcohol craving in trauma-exposed drinkers. It offers a methodological framework in which to evaluate novel strategies that aim to disrupt negative reinforcement drinking in individuals with co-occurring PTSD and AUD.

Evaluating the influences of major depression and posttraumatic stress disorder on trauma and alcohol cue reactivity

Despite support for the role of self-medication alcohol use in the etiology and maintenance of comorbid posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD), theoretical and empirical models of PTSD-AUD rarely account for the role of common comorbidities in risk processes, such as major depressive disorder (MDD). The current study examined the main and interactive effects of PTSD and depressive symptoms on patterns of trauma and alcohol cue reactivity to elucidate potential influences of depression on conditioned craving responses to trauma memories. It was hypothesized that depressive symptoms would be associated with greater cue reactivity (i.e., craving and salivation) to personalized trauma cues, above and beyond the influence of PTSD symptoms. Participants were 184 trauma-exposed young adults (50% female) endorsing current weekly alcohol use. Patterns of craving and salivation were assessed in response to four combinations of narrative (trauma vs. neutral) and beverage (alcohol vs. water) cues. Forward-fitted linear mixed effects models with deviance testing were conducted to ascertain the impact of the within-subjects factors (narrative and beverage cues) and covariates (PTSD and depressive symptoms) on self-reported and physiological (salivation) alcohol craving. Depressive symptoms were associated with elevated drinking coping motives, AUD symptom severity, and alcohol use problems at baseline; however, depressive symptoms did not show main or interactive effects with narrative or beverage cues to predict craving or salivation, p's > 0.05. Results suggest that, in the context of PTSD symptoms, depressive symptoms may not exacerbate alcohol craving responses to trauma reminders or alcohol cues.

Salivary measurement and mindfulness-based modulation of prescription opioid cue-reactivity

BACKGROUND

Chronic pain patients on long-term opioid therapy (LTOT) may be at elevated risk for developing conditioned opioid cue-reactivity as their prescribed dosing schedules simultaneously function as fixed reinforcement schedules. Since opioids are typically consumed orally during LTOT, it stands to reason that opioid cue exposure might elicit conditioned salivary responses. However, no study has examined salivary cue-reactivity among opioid users during in-vivo exposure to their own prescription opioid medication.

METHODS

Two samples (N = 68, N = 39) of chronic pain patients on LTOT were recruited from primary care and specialty care clinics. Study 1 aimed to determine whether chronic pain patients receiving LTOT exhibited salivary cue-reactivity to their prescribed opioid. Study 2 was a pilot study that aimed to assess the effects of behavioral treatment on chronic pain patients' salivary cue-reactivity.

RESULTS

In Study 1, exposure to the patient's own prescribed opioid resulted in significantly greater increases in salivation and cue-elicited craving than exposure to a neutral cue. In Study 2 participants who were randomized to an 8-week Mindfulness-Oriented Recovery Enhancement intervention evidenced significantly greater decreases in opioid cue-reactivity than participants in an active control condition as evidenced by both reduced salivation and craving ratings.

CONCLUSIONS

Study findings demonstrate salivation may serve as a useful, objective index of opioid cue-reactivity. With further refinement of this task, conditioned salivary response could be used to identify especially vulnerable patients, who then could be targeted with a personalized medicine approach for selective and intensive prevention/treatment interventions to preempt escalation of opioid use to opioid misuse and OUD.

A novel human laboratory model for screening medications for alcohol use disorder

Background

Alcohol use disorder (AUD) is a highly prevalent, chronic relapsing disorder with a high disease burden in the USA. Pharmacotherapy is a promising treatment method for AUD; however, the few FDA-approved medications are only modestly effective. Medications development for AUD is a high priority research area, but the cumbersome drug development process hinders many potential compounds from reaching approval. One area with major opportunities for improvement is the process of screening novel compounds for initial efficacy, also known as early phase 2 trials. Early phase 2 trials incorporate human laboratory paradigms to assess relevant clinical constructs, such as craving and subjective responses to alcohol. However, these controlled paradigms often lack the ecological validity of clinical trials. Therefore, early phase 2 trials can be more efficient and clinically meaningful if they combine the internal validity of experimental laboratory testing with the external validity of clinical trials. To that end, the current study aims to develop and validate a novel early efficacy paradigm, informed by smoking cessation literature, to screen novel medications for AUD. As an established AUD medication, naltrexone will serve as an active control to test both the practice quit attempt model and the efficacy of a promising AUD pharmacotherapy, varenicline.

Methods

Individuals with current AUD reporting intrinsic motivation to change their drinking will complete a week-long “practice quit attempt” while on study medication. Participants are randomized and blinded to either naltrexone, varenicline, or placebo. During the practice quit attempt, participants will complete daily visits over the phone and fill out online questionnaires regarding their drinking, alcohol craving, and mood. Additionally, participants will undergo two alcohol cue-reactivity sessions.

Discussion

The successful completion of this study will advance medications development by proposing and validating a novel early efficacy model for screening AUD pharmacotherapies, which in turn can serve as an efficient strategy for making go/no-go decisions as to whether to proceed with clinical trials.

Trial registration

ClinicalTrials.gov NCT04249882. Registered on 31 January 2020.

Intravenous Alcohol Administration Selectively Decreases Rate of Change in Elasticity of Demand in Individuals With Alcohol Use Disorder

BACKGROUND

Alcohol demand is a key behavioral economic concept that provides an index of alcohol's relative reinforcing value. Initial studies have reported that alcohol demand increases during alcohol administration and in response to alcohol cues. However, the extent to which these effects are observed explicitly in samples composed of individuals with alcohol use disorder (AUD) and are operative in conjunction with each other has not been studied.

METHODS

To address this gap in the literature, we assessed alcohol demand during an alcohol challenge and subsequent alcohol cue-exposure paradigm in non-treatment-seeking, alcohol-dependent (i.e., DSM-IV criteria) participants (N = 27). Specifically, participants completed 2 counterbalanced intravenous, placebo-controlled, alcohol administration sessions followed by a controlled cue-exposure paradigm. At baseline and at breath alcohol concentration of 0.06 g/dl, participants completed the alcohol purchase task, assessing estimated alcohol consumption at escalating prices. Participants were also assessed for alcohol demand following each cue exposure.

RESULTS

During alcohol administration, there was a significant decrease in the rate of change in elasticity compared with placebo, and during the cue-reactivity paradigm, there was a significant main effect such that alcohol cues decreased the rate of change in elasticity relative to water cues. There were no statistically significant differences in other demand indices.

CONCLUSIONS

These findings provide further evidence that alcohol administration increases price insensitivity and extends the literature on alcohol's effects on demand by using a clinical sample with AUD and by adding a placebo-alcohol condition.

Examining the Relationship Between Self-Reported Drinking and In-Laboratory Drinking and Craving: Is There Concordance?

BACKGROUND

In-laboratory drinking sessions that allow direct assessment of drinking and craving are an emerging method for testing novel pharmacotherapy compounds and behavioral interventions for alcohol use disorders. Despite wide implementation, limited evidence supports the concordance between drinking in the laboratory and in a natural setting. This study examined the relationship between self-reports of drinking prior to and drinking and craving during an alcohol drinking paradigm (ADP).

METHODS

Participants were adult heavy drinkers (N = 64) who participated in a pharmacotherapy study. Participants completed self-report alcohol assessments and a baseline ADP session prior to any medication administration. Alcohol craving was assessed during priming and ad lib ADP phases. Outcomes were the associations of total drinks consumed in-laboratory and summary drinking measures for the 30 days prior to the ADP and reports of maximum drinks (past year and lifetime). Additional outcomes were the association of self-reported drinking and alcohol craving during the ADP and the concordance between self-report and ADP World Health Organization (WHO) drinking classifications.

RESULTS

Number of drinking days, average drinks per drinking occasion, and lifetime and past-year maximum drinks were all related to drinking in the laboratory. Heavy drinking days were not related to drinking in the laboratory but were associated with ADP craving. Alcohol craving was also associated with other measures of self-reported drinking. There was also a significant association between WHO drinking risk classification and in-laboratory drinking.

CONCLUSIONS

The observed relationships between self-reported drinking and drinking in-laboratory across drinking indices suggest that in-laboratory alcohol consumption may reflect participants' real-world alcohol consumption, supporting the value of laboratory-based drinking paradigms. The demonstrated relationship with self-reported drinking and ADP alcohol craving further supports the value of such paradigms to model key drinking predictors. These results provide support for the validity of laboratory-based paradigms to accurately reflect participants' recent drinking levels.

A persistent alcohol cue memory trace drives relapse to alcohol seeking after prolonged abstinence

Alcohol use disorder is characterized by a high risk of relapse during periods of abstinence. Relapse is often triggered by retrieval of persistent alcohol memories upon exposure to alcohol-associated environmental cues, but little is known about the neuronal circuitry that supports the long-term storage of alcohol cue associations. We found that a small ensemble of neurons in the medial prefrontal cortex (mPFC) of mice was activated during cue-paired alcohol self-administration (SA) and that selective suppression of these neurons 1 month later attenuated cue-induced relapse to alcohol seeking. Inhibition of alcohol seeking was specific to these neurons as suppression of a non-alcohol-related or sucrose SA-activated mPFC ensemble did not affect relapse behavior. Hence, the mPFC neuronal ensemble activated during cue-paired alcohol consumption functions as a lasting memory trace that mediates cue-evoked relapse long after cessation of alcohol intake, thereby providing a potential target for treatment of alcohol relapse vulnerability.

Baclofen modulates cardiovascular responses to appetitive cues in treatment-seeking alcohol use disorder individuals

OBJECTIVE

To assess whether baclofen-treated alcohol dependent participants show different subjective and psychophysiological responses to appetitive cues during an alcohol cue reactivity task compared to placebo, and whether these responses are associated with prospective drinking outcomes.

METHODS

Forty-two alcohol dependent participants (placebo: n = 12, low-dose baclofen [30 mg/day] n = 18, high-dose baclofen [75 mg/day]: n = 12) completed an alcohol cue reactivity task, whereby water and alcohol beverage cues were presented, with subsequent recovery periods, and subjective alcohol craving and psychophysiological indices (skin conductance; cardiovascular measures: heart rate, high-frequency heart rate variability) were recorded.

RESULTS

High-dose baclofen-treated participants showed both overall cue reactivity to water and alcohol cues and greater recovery effects during recovery periods, revealed by high-frequency heart rate variability, when compared to low-dose- and placebo-treated participants. There were no medication effects on subjective craving. In high-dose baclofen participants only, there was a predictive effect of lower baseline heart rate variability and fewer post-test percentage of heavy drinking days.

CONCLUSION

There was a dose-specific rescuing effect of high-dose baclofen on the dynamic modulation of cardiovascular responses to eliciting cues. Investigation of treatment responses using psychophysiological techniques may elucidate baclofen's mechanisms of action, and identify subgroups amenable to treatment.

Acute Effect of Eating Sweets on Alcohol Cravings in a Sample with At-Risk Drinking

BACKGROUND

Alcohol craving, or the desire to drink alcohol, has been identified as a key experience preceding alcohol use. Alcoholics Anonymous has long claimed that individuals can allay alcohol cravings by eating sweets. Empirical tests of this strategy are limited to a few preclinical studies in rats, and there is no existing experiment testing the acute effect of eating sweets on alcohol cravings in humans.

PURPOSE

The current study sought to experimentally test the acute effect of eating sweets on alcohol cravings in a sample with at-risk drinking.

METHODS

After being exposed to an alcohol cue, individuals with at-risk drinking (N = 150) were randomly assigned to eat sweets (n = 60), eat calorie-equivalent bland food (n = 60), or watch a video (n = 30). Caloric amounts were manipulated. Individuals with at-risk drinking were then exposed to a second alcohol cue. Changes in alcohol cravings from after the first to after the second alcohol cue were measured via visual analog scale and heart rate.

RESULTS

There were no significant between-group differences in changes in alcohol cravings. Caloric amounts did not modify effects.

CONCLUSIONS

Experimental findings did not provide evidence to support the clinical lore that eating sweets can reduce alcohol cravings, albeit only acutely and for those with at-risk drinking. Other empirically supported strategies for managing alcohol cravings (e.g., pharmacotherapies, mindfulness) could instead be promoted.

Evidence for incentive salience sensitization as a pathway to alcohol use disorder

The incentive salience sensitization (ISS) theory of addiction holds that addictive behavior stems from the ability of drugs to progressively sensitize the brain circuitry that mediates attribution of incentive salience (IS) to reward-predictive cues and its behavioral manifestations. In this article, we establish the plausibility of ISS as an etiological pathway to alcohol use disorder (AUD). We provide a comprehensive and critical review of evidence for: (1) the ability of alcohol to sensitize the brain circuitry of IS attribution and expression; and (2) attribution of IS to alcohol-predictive cues and its sensitization in humans and non-human animals. We point out gaps in the literature and how these might be addressed. We also highlight how individuals with different alcohol subjective response phenotypes may differ in susceptibility to ISS as a pathway to AUD. Finally, we discuss important implications of this neuropsychological mechanism in AUD for psychological and pharmacological interventions attempting to attenuate alcohol craving and cue reactivity.

Effects of Oxytocin Administration on Cue-Induced Craving in Co-occurring Alcohol Use Disorder and PTSD: A Within-Participant Randomized Clinical Trial

BACKGROUND

Individuals with alcohol use disorder (AUD) are much more likely to meet criteria for posttraumatic stress disorder (PTSD) than the general population. Compared to AUD alone, those with comorbid AUD-PTSD experience worse outcomes. Prior literature suggests that oxytocin, a hypothalamic neuropeptide, may be effective in the treatment of both AUD and PTSD when administered intranasally, although specific mechanisms remain elusive.

METHODS

Forty-seven male patients with comorbid AUD-PTSD were administered intranasal oxytocin in a randomized, double-blind, dose-ranging (20 IU, 40 IU, and matched placebo), within-participant design with study visits at least 1 week apart. A cue-induced craving paradigm was conducted using each participant's preferred alcoholic beverage versus a neutral water cue. Self-reported alcohol craving and heart rate (HR) were recorded and analyzed using linear mixed-effect models.

RESULTS

While alcohol cues significantly induced self-reported craving and increased HR compared to neutral water cues, neither dosage of oxytocin compared to placebo reduced self-reported cue-induced alcohol craving nor cue-induced changes in HR in patients with PTSD-AUD.

CONCLUSIONS

These preliminary findings suggest that oxytocin does not affect cue-induced craving. Our results contribute to an ever-growing field of research investigating the effects of intranasal oxytocin on the symptoms of substance use disorders and will help further refine methodology and streamline future inquiries in this area.

The Use of Functional Magnetic Resonance Imaging to Test Pharmacotherapies for Alcohol Use Disorder: A Systematic Review

Alcohol use disorder (AUD) is a chronic relapsing condition that represents a significant public health concern. Pharmacological treatment development for AUD is a top research priority, and many studies are being conducted to evaluate potential AUD treatments. Understanding the brain circuitry impacted by addiction is crucial for the development of efficacious pharmacological interventions. These neuroadaptations can be probed noninvasively using functional magnetic resonance neuroimaging (fMRI). fMRI may be an effective tool to identify biomarkers for AUD pharmacotherapies, evaluating changes associated with pharmacological treatment. Thus, the present qualitative review of the literature focuses on the role of fMRI as a tool for medication development for AUD. The aim of this review was to assemble research across a range of fMRI paradigms to study the effectiveness of pharmacological treatments of adult AUD. First, we present a qualitative review of fMRI AUD pharmacotherapy studies, differentiating studies based on their dosing regimen. Second, we provide recommendations for the field to improve the use of fMRI as a biomarker for AUD pharmacotherapy.

Comparing alcohol cue-reactivity in treatment-seekers versus non-treatment-seekers with alcohol use disorder

Background: Recent studies have examined the distinction between treatment-seekers and non-treatment-seekers with alcohol use disorder (AUD) with a focus on treatment development.Objectives: To advance our understanding of treatment-seeking in clinical research for AUD, this study compares treatment-seekers to non-treatment-seekers with AUD on alcohol cue-reactivity (CR).Methods: A community sample (N = 65, 40% female) of treatment-seeking (n = 32, 40.6% female) and non-treatment-seeking individuals (n = 33, 39.4% female) with a DSM-5 diagnosis of moderate-to-severe AUD completed a laboratory CR paradigm. Analyses compared the two groups on subjective alcohol craving, heart rate, and blood pressure after the presentation of water cues and alcohol cues.Results: Mixed-design analyses of variance revealed a main effect of treatment-seeking status (i.e., group; p = .02), such that treatment-seekers reported higher levels of subjective craving across both water (p = .04) and alcohol (p = .03) cue types. However, analyses did not support a group × cue type interaction effect (p = .9), indicating that treatment-seekers were not more cue-reactive. Group differences in craving were no longer significant when controlling for AUD severity. On blood pressure and heart rate, there was no significant effect of cue type, group, or cue type × group (p's > 0.13).Conclusion: These findings suggest that while treatment-seekers report higher levels of subjective craving than non-treatment-seekers, they are not more cue-reactive. Under the framework of medications development, we interpret these null findings to indicate that non-treatment seeking samples may be informative about CR and therefore, medication-induced effects on CR.

Cue-Reactive Imagery Mediates the Relationships of Reward Responsiveness with Both Cue-Reactive Urge to Gamble and Positive Affect in Poker-Machine Gamblers

Previous research has demonstrated that gambling cues (e.g., flashing lights on poker-machines) can trigger an urge to gamble in poker-machine gamblers. However, the psychological mechanisms that promote the urge to gamble remain poorly understood. The present study explored whether reward responsiveness predicted urge to gamble and positive affect, and whether cue-reactive rationality, volitional control and imagery mediated these relationships. Ninety-three (45% male and 55% female) Australian regular poker-machine gamblers aged between 18 and 77 participated in an online cue-reactivity experiment. Participants initially completed the Problem Gambling Severity Index and Reward Responsiveness scale. Subsequently, at three time points (i.e., baseline, directly after a neutral cue and directly after a gambling cue) participants completed the rationality, volitional control and imagery subscales of the Phenomenology of Consciousness Inventory and two visual analogue scales that measured urge to gamble and positive affect. Analyses indicated that gambling cues triggered statistically significant increases in both urge to gamble and positive affect and these variables were statistically significantly positively correlated with reward responsiveness. Furthermore, only cue-reactive imagery mediated the relationships between reward responsiveness and the two outcome variables (i.e., cue-reactive urge to gamble and positive affect). These findings highlight the potential importance of targeting reward responsiveness and cue-reactive mental imagery in the context of exposure therapies for poker-machine problem gamblers.

Effects of Citalopram on Cue-Induced Alcohol Craving and Thalamic D2/3 Dopamine Receptor Availability

BACKGROUND

Selective serotonin reuptake inhibitors are often used in alcohol use disorders. Clinical trials with selective serotonin reuptake inhibitors for alcohol use disorders, however, have yielded mixed results. The goal of this project was to assess whether a single i.v. dose of a selective serotonin reuptake inhibitor reduces craving for alcohol and/or simultaneously increases striatal dopamine concentration in individuals with alcohol dependence.

METHODS

Alcohol-dependent (DSM-IV-TR criteria) volunteers and matched controls (n = 10/group) underwent a double-blind, placebo-controlled, within-subjects study. Participants received i.v. citalopram (40 mg) or saline (counter-balanced) followed by a cue-induced craving assessment and [18F]-fallypride positron emission tomography scanning.

RESULTS

In the alcohol-dependent individuals, the citalopram (compared with saline) resulted in decreased cue-induced craving for alcohol. For the whole study group, cue-induced alcohol craving was inversely correlated with thalamic (but not striatal) dopamine D2/3 receptor availability.

CONCLUSIONS

Acute serotonin reuptake inhibition reduces cue-induced alcohol craving. Furthermore, thalamic dopamine abnormalities and the striatal hyperdopaminergic hypothesis of alcohol use disorder are supported.

Neural correlates of tobacco cue reactivity predict duration to lapse and continuous abstinence in smoking cessation treatment

It has been hypothesized that neural reactivity to drug cues in certain limbic/paralimbic regions of the brain is an indicator of addiction severity and a marker for likelihood of success in treatment. To address this question, in the current study, 32 participants (44 percent female) completed a functional magnetic resonance imaging cigarette cue exposure paradigm 2 hours after smoking, and then enrolled in a 9-week smoking cessation treatment program. Neural activation to smoking cues was measured in five a priori defined limbic/paralimbic regions previously implicated with cue reactivity across substances. These included regions of the ventral striatum, anterior cingulate cortex and amygdala. Cox proportional hazard modeling was conducted to predict the number of days to first smoking lapse by using neural activation in these regions. Greater neural activation during pre-treatment exposure to smoking cues in the right ventral striatum, the left amygdala, and the anterior cingulate was associated with longer periods of abstinence following cessation. A similar pattern was present for continuous abstinence for the full duration of treatment. While baseline levels of nicotine dependence were strongly associated with treatment outcome, activation in the right ventral striatum predicted duration of abstinence beyond level of nicotine dependence. These results suggest that pre-treatment reactivity to smoking cues in areas associated with cue reactivity may be associated with successfully maintaining abstinence during treatment. This is consistent with models that propose that as addiction becomes more severe, motivational processing shifts from regions that subserve reward salience and learning to regions responsible motor behavior and habit learning.

Mindfulness buffers the effects of cue-induced craving on alcohol demand in college drinkers

Alcohol consumption among young adult college students represents a significant public health problem. The presence of alcohol-related cues in drinkers' environments can trigger powerful alcohol cravings, which may influence drinking outcomes. Less is known about how this cue-induced craving influences behavioral economic demand for alcohol. In addition, research has suggested that trait mindfulness may be an important buffer of the effects of internal states of craving on drinking decisions. Based on this literature, we hypothesized that cue-induced cravings would be associated with increased alcohol demand, an effect that would be attenuated among drinkers who have higher levels of mindfulness. Young adult college student drinkers (n = 69) completed a laboratory-based cue-induced craving assessment, a self-report assessment of trait mindfulness, and an alcohol purchase task. Findings revealed that cue-induced craving was related to higher alcohol demand. Consistent with the study hypothesis, acceptance, a component of mindfulness, buffered the effects of cue-induced craving on alcohol demand. Results raise the possibility that mindfulness-based interventions may be useful in helping disrupt the link between internal states of craving and drinking decisions in young adult college student drinkers.

Neural responses to cues paired with methamphetamine in healthy volunteers

Drug cues, or conditioned responses to stimuli paired with drugs, are widely believed to promote drug use. The acquisition of these conditioned responses has been well characterized in laboratory animals: neutral stimuli paired with drugs elicit conditioned responses resembling the motivational and incentive properties of the drug itself. However, few studies have examined acquisition of conditioning, or the nature of the conditioned response, in humans. In this study, we used fMRI to examine neural responses to stimuli that had been paired with methamphetamine or placebo in healthy young adults. Participants first underwent four conditioning sessions in which visual-auditory stimuli were paired with either methamphetamine (20 mg, oral) or placebo. Then on a drug-free test day, the stimuli were presented during an fMRI scan to assess neural responses to the stimuli. We hypothesized that the stimuli would elicit drug-like brain activity, especially in regions related to reward. Instead, we found that the methamphetamine-paired stimuli, compared to placebo-paired stimuli, produced greater activation in regions related to visual and auditory processing, consistent with the drug's unconditioned effects on sensory processing. This is the first study to demonstrate conditioned neural responses to drug-paired stimuli after just two pairings of methamphetamine in healthy adults. The study also illustrates that conditioned responses may develop to unexpected components of the drug's effects.

Characterizing conditioned reactivity to sequential alcohol-predictive cues in well-trained rats

Implicit learning about antecedent stimuli and the unconditional stimulus (US) properties of alcohol may facilitate the progressive loss of control over drinking. To model this learning, Cofresí et al. (2017) developed a procedure in which a discrete, visual conditional stimulus (houselight illumination; CS) predicted the availability of a retractable sipper that rats could lick to receive unsweetened alcohol [Alcoholism: Clinical and Experimental Research, 41, 608-617]. Here we investigated the possibility that houselight illumination, sipper presentation, and oral alcohol receipt might each exert control over alcohol seeking and drinking. We also determined the relationship between ingested dose and blood alcohol concentration, in order to validate the idea that the US is a post-ingestive action of alcohol. Finally, we tested a major prediction from the conditioning account of problematic drinking [Tomie, A., & Sharma, N. (2013). Current Drug Abuse Reviews, 6, 201-219], which is that once learned, responses elicited by a CS will promote drinking. We found that despite having constrained opportunities to drink alcohol during the conditioning procedure, ingested doses produced discriminable blood concentrations that supported cue conditioning. Based on our analysis of the dynamics of cue reactivity in well-trained rats, we found that houselight illumination triggered conditioned approach, sipper presentation evoked licking behavior, and alcohol receipt promoted drinking. Reactivity to these cues, which varied in terms of their temporal proximity to the alcohol US, persisted despite progressive intoxication or satiety. Additionally, rats with the greatest conditioned reactivity to the most distal alcohol cue were also the fastest to initiate drinking and drank the most. Our findings indicate that the post-ingestive effects of alcohol may condition multiple cues simultaneously in adult rats, and these multiple cues help to trigger alcohol seeking and drinking. Moreover, identification and characterization of these cues should be helpful for designing interventions that attenuate the power of these cues over behavior.

The Role of the Ghrelin System in Drug Addiction

In the past years, a significant volume of research has implicated the appetitive hormone ghrelin in the mechanisms underlying drug use and addiction. From a neuroscientific standpoint, ghrelin modulates both reward and stress pathways, two key drivers of substance use behaviors. Previous investigations support a connection between the ghrelin system and alcohol, stimulants, and tobacco use in both animals and humans, while the research on opioids and cannabis is scarce. In general, upregulation of the ghrelin system seems to enhance craving for drugs as well as substances use. On the other hand, acute and chronic exposure to drugs of abuse influences the ghrelin system at different levels. This chapter summarizes the literature on the relationship between the ghrelin system and substance-related behaviors. We also review recent work investigating the ghrelin system as a potential pharmacological target for treating substance use disorders and discuss the need for additional research.

Effects of varenicline on alcohol cue reactivity in heavy drinkers

RATIONALE

Clinical trials and human laboratory studies have established that varenicline can reduce rates of alcohol use among heavy drinkers. Less is known about the mechanisms by which varenicline has this effect on drinking behavior. Reactivity to alcohol cues is often cited as the primary cause of relapse among those being treated for alcohol use disorder, and several front-line treatments for alcohol use disorder work, at least in part, by minimizing cue-induced alcohol craving.

OBJECTIVE

The current double-blind, placebo-controlled human laboratory study tested the effects of varenicline on alcohol cue reactivity in a group of heavy-drinking adult smokers and nonsmokers.

METHODS

As part of a larger series of sequential human laboratory experiments testing the effects of varenicline on drinking outcomes, participants were assigned (between-participant) to receive either active varenicline (2 mg/day) or placebo. Following a titration period, participants (n = 77) attended a laboratory session during which they were exposed to alcohol and neutral cues using a standard cue reactivity paradigm.

RESULTS

Alcohol cue exposure increased craving for alcohol in both medication groups. However, participants receiving varenicline showed a smaller increase in alcohol craving compared to participants receiving placebo. The medication effect did not differ between smokers and nonsmokers. Among smokers, alcohol cue exposure also increased tobacco craving. Varenicline did not attenuate this effect.

CONCLUSIONS

Results support the use of varenicline for reducing alcohol use in heavy drinkers and identify a potential mechanism by which varenicline reduces drinking. Varenicline continues to show promise as a pharmacological treatment for alcohol use disorder.

Development of the Neuroimmune Modulator Ibudilast for the Treatment of Alcoholism: A Randomized, Placebo-Controlled, Human Laboratory Trial

Current directions in medication development for alcohol use disorder (AUD) emphasize the need to identify novel molecular targets and efficiently screen new compounds aimed at those targets. Ibudilast (IBUD) is a neuroimmune modulator that inhibits phosphodiesterase-4 and -10 and macrophage migration inhibitory factor and was recently found to reduce alcohol intake in rats by ∼50%. To advance medication development for AUD, the present study consists of a randomized, crossover, double-blind, placebo-controlled laboratory study of IBUD in nontreatment-seeking individuals with current (ie, past month) mild-to-severe AUD. This study tested the safety, tolerability, and initial human laboratory efficacy of IBUD (50 mg b.i.d.) on primary measures of subjective response to alcohol as well as secondary measures of cue- and stress-induced changes in craving and mood. Participants (N=24) completed two separate 7-day intensive outpatient protocols that included daily visits for medication administration and testing. Upon reaching a stable target dose of IBUD (or matched placebo), participants completed a stress-exposure session (day 5; PM), an alcohol cue-exposure session (day 6; AM), and an i.v. alcohol administration session (day 6; PM). Participants stayed overnight after the alcohol administration, and discharge occurred on day 7 of the protocol. Medication conditions were separated by a washout period that was ⩾7 days. IBUD was well tolerated; however, there were no medication effects on primary measures of subjective response to alcohol. IBUD was associated with mood improvements on the secondary measures of stress exposure and alcohol cue exposure, as well as reductions in tonic levels of craving. Exploratory analyses revealed that among individuals with higher depressive symptomatology, IBUD attenuated the stimulant and mood-altering effects of alcohol as compared with placebo. Together, these findings extend preclinical demonstrations of the potential utility of IBUD for the treatment of AUD and suggest that depressive symptomatology should be considered as a potential moderator of efficacy for pharmacotherapies with neuroimmune effects, such as IBUD.

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

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

Naltrexone moderates the relationship between cue-induced craving and subjective response to methamphetamine in individuals with methamphetamine use disorder

RATIONALE

Reductions in cue-induced craving and subjective response to drugs of abuse are commonly used as initial outcome measures when testing novel medications for the treatment of addiction. Yet neither the relationship between these two measures at the individual level nor the moderating effects of pharmacotherapies on this relationship has been examined.

OBJECTIVE

This secondary data analysis sought to examine (1) the predictive relationship between cue-induced craving and subsequent acute subjective response to methamphetamine (MA) and (2) whether the opioid-receptor antagonist naltrexone moderated this association in a sample of non-treatment-seeking individuals who met DSM-IV criteria for MA use disorder (abuse or dependence).

METHODS

Participants (n = 30) completed two 4-day medication regimens (oral naltrexone 50 mg or placebo, in a randomized, counterbalanced, and double-blind fashion). On day 4 of each medication regimen, participants completed a cue-reactivity paradigm followed by intravenous MA administration. Methamphetamine craving was assessed after the cue-reactivity paradigm, and subjective response to MA was assessed during MA infusion.

RESULTS

Cue-induced craving for MA was positively associated with post-infusion subjective MA effects, including positive (i.e., stimulation, good effects, feel drug, high), negative (i.e., anxious and depressed), and craving-related (i.e., want more, would like access to drug, crave) responses. Naltrexone, vs. placebo, significantly reduced the association between cue-induced craving and positive subjective response to MA.

CONCLUSIONS

The findings indicate that naltrexone moderates the predictive relationship between cue-induced craving and positive subjective effects of MA, thereby suggesting a behavioral mechanism by which naltrexone may be efficacious in treating MA use disorder.

Medications development for the treatment of alcohol use disorder: insights into the predictive value of animal and human laboratory models

Development of effective treatments for alcohol use disorder (AUD) represents an important public health goal. This review provides a summary of completed preclinical and clinical studies testing pharmacotherapies for the treatment of AUD. We discuss opportunities for improving the translation from preclinical findings to clinical trial outcomes, focusing on the validity and predictive value of animal and human laboratory models of AUD. Specifically, while preclinical studies of medications development have offered important insights into the neurobiology of the disorder and alcohol's molecular targets, limitations include the lack of standardized methods and streamlined processes whereby animal studies can readily inform human studies. Behavioral pharmacology studies provide a less expensive and valuable opportunity to assess the feasibility of a pharmacotherapy prior to initiating larger scale clinical trials by providing insights into the mechanism of the drug, which can then inform recruitment, analyses, and assessments. Summary tables are provided to illustrate the wide range of preclinical, human laboratory, and clinical studies of medications development for alcoholism. Taken together, this review highlights the challenges associated with animal paradigms, human laboratory studies, and clinical trials with the overarching goal of advancing treatment development and highlighting opportunities to bridge the gap between preclinical and clinical research.