Addiction Neuroscience

We previously reported, using in-vivo fiber photometry, that operant responding reinforced by access to a peer (social self-administration) is associated with phasic dopamine increases in nucleus accumbens (NAc) core following lever insertion (reward-availability cue) and gradual increases preceding lever-pressing. Here, we sought to replicate these findings and determine whether dopamine signals (1) generalize to responding for high-carbohydrate palatable food, (2) show opposite patterns during negative reinforcement (shock avoidance/escape), and (3) depend on whether reinforcers are experienced alone or together. We trained rats (n=11; 6 females) to lever-press for access to a same-sex peer (15 s/trial) and palatable food (45-mg pellet/trial), followed by shock avoidance/escape (0.18-0.26 mA). After training, we expressed the dopamine sensor GRAB-DA2m and implanted optic fibers into NAc core. We measured dopamine activity during sessions with either one- or three-reinforcers. During social self-administration, dopamine activity showed phasic increases following lever insertion and gradual increases preceding lever-pressing; responses were moderately greater during sessions with all three reinforcers. Palatable food self-administration showed a similar pattern, but responses were approximately twofold greater during single-reinforcer sessions. During shock avoidance/escape, dopamine activity showed phasic decreases at warning onset, lever insertion, and shock onset; responses were also greater during single-reinforcer sessions. Results suggest that NAc core dopamine signaling distinguishes positive from negative reinforcement and is modulated by reinforcer availability. Compared with single-reinforcer sessions, dopamine responses during food self-administration and shock avoidance/escape were reduced during sessions with all three reinforcers, whereas responses during social self-administration modestly increased. Significance statementNucleus accumbens (NAc) dopamine is critical for processing the valence of positive reinforcers, whereas its role in negative reinforcement is less well understood. Here, we extended our prior work on operant social self-administration to determine whether these findings generalize to food reinforcement, show the opposite pattern during operant negative reinforcement (shock avoidance/escape), and depend on whether reinforcers are experienced alone or together. Results suggest that NAc core dopamine activity differentiates positive and negative reinforcement and is modulated by the presence of other available reinforcers. Specifically, dopamine responses during food self-administration and shock avoidance/escape were reduced when all three reinforcers were available together compared with when each reinforcer was experienced alone, whereas responses during social self-administration showed the opposite pattern.

Binge drinking is characterized by an initial bout of rapid, high-vigor alcohol intake (front-loading) followed by a prolonged period of lower-rate "maintenance" drinking, yet the circuit mechanisms that generate and regulate these phases remain unclear. Here, we develop a systems-level computational model that links the structure of binge drinking to interactions among medial prefrontal cortex (mPFC), insula, striatum, and ventral tegmental area (VTA). The model consists of cortical Seek (mPFC) and Go (insula) populations that form a mutually excitatory loop, a SetPoint population that integrates striatal activity as an internal estimate of effort/consumption, ventral (nucleus accumbens, NAc) and dorsal (dorsolateral striatum, DLS) striatal populations, and a dopaminergic VTA population providing transient reward-prediction signaling. Using a firing-rate formalism with noisy dynamics, we reproduce the canonical two-phase binge pattern and show that: (i) the PFC-insula loop acts as a bistable module that initiates and sustains front-loading; (ii) striato-cortical feedback to the Setpoint population controls the timing of the transition from front-loading to maintenance without altering its vigor; and (iii) the amplitude of the VTA dopamine transient selectively scales front-loading intensity. Sensitivity analyses identify PFC-insula connectivity, VTA-to-NAc modulation, and striato-cortical feedback as key parameters that bifurcate two-phase drinking into regimes with abolished or persistent front-loading. These findings provide a mechanistic framework for interpreting binge-like alcohol intake in terms of identifiable circuit motifs and generate testable predictions for targeting mPFC-insula-striatal-VTA interactions in alcohol use disorder.

Quantifying decision-making in experimental settings that mimic real-world conditions may provide insights into mechanisms underlying addiction. This study developed a computational model of opioid-seeking behavior. Out-of-treatment persons who regularly used heroin were stabilized on buprenorphine 8mg/day to minimize opioid withdrawal. Across programmatically-linked studies, three experimental conditions presented differing money vs. opioid unit amounts that could be earned per trial ($2 vs. 1-mg hydromorphone, n=23; $2 vs. 2-mg hydromorphone, n=36; $4 vs. 2-mg hydromorphone, n=24), controlling other factors. Progressive ratio schedules on each choice option required increasing effort across trials to earn the same amount. Trial-level outcomes were decision latency and choice on each option, and session-level outcomes were drug-money latency and breakpoint difference scores. A Markov computational model was used to predict the probability of choosing the same option as the previous trial (vs. switching). Model inputs included effort discrepancy (between earning the same vs. other commodity on next choice) and logarithm of the ratio of decisional speed (current vs. previous choice). Participants who more rapidly chose hydromorphone vs. money made more consecutive drug choices and expended greater effort earning hydromorphone. First-trial hydromorphone choice predicted continued effortful opioid-seeking. Participants repeated choices on 80% of trials; the model accurately predicted stick vs. switch behavior on 93% of trials. Participants typically repeated choices when faced with lower effort discrepancies and higher hydromorphone dose (2-mg vs. 1-mg). In conclusion, a Markov computational model accurately predicted effortful behavior in a choice paradigm that mimics real-world decisions between opioid and nondrug reinforcers.

4-hydroxytamoxifen (4-OHT) is commonly used to facilitate activity-dependent recombination in neurons. Here we show that one dose of 4-OHT devalues alcohol, contexts, and tastants, indicating that experimental designs using 4-OHT should control for its aversiveness. Further, reactivation of 4-OHT-responsive neurons causes conditioned taste avoidance. An activity screen coupled with graph theoretical analysis identifies candidate brain areas mediating these effects. We suggest these areas could be therapeutic targets for treating addiction.

Background: Substance use disorders (SUDs) are associated with impaired goal-directed decision-making, but the specific cognitive mechanisms underlying these deficits remain unclear. Forward planning, a key component of goal-directed control, requires strategies to contain computational demand and ensure feasibility through heuristics such as reducing planning depth, pruning unlikely options, and discounting probabilistic outcomes. This study investigated whether individuals with alcohol use disorder (AUD) and tobacco use disorder (TUD) differ from healthy controls in their use of these heuristics during sequential decision-making. Methods: We examined participants from the general population meeting criteria for at least moderate AUD (n = 45), TUD (n = 49), or both (n = 45), and compared them with matched healthy control groups. To assess forward planning, we used a previously published probabilistic three-step Markov decision task. Computational modeling was used to infer individual planning depths and compare model variants incorporating low-probability pruning, probability discounting, or both. Results: A combined model including both low-probability pruning and probability discounting best explained participants' behavior and was subsequently used for analysis. Compared to matched healthy controls, all groups with SUD exhibited significantly reduced planning depth. Moreover, individuals with SUD tended to show stronger probability discounting, with this effect reaching statistical significance in the comorbid group. Conclusion: Individuals with AUD and/or TUD engaged in forward planning using similar strategies as healthy controls but exhibited reduced planning depth and a tendency toward stronger probability discounting. These findings suggest the presence of altered planning processes in SUD, which could contribute to maladaptive decision-making. Future research is needed to clarify whether such differences reflect pre-existing cognitive traits, consequences of substance use, or both, and to explore their potential relevance for intervention.

Chronic ethanol consumption produces long-lasting effects on the brain that contribute to persistent behavioral changes. This has been modeled in animals using the chronic intermittent ethanol (CIE) paradigm, which induces escalation of consumption and alterations in affective and cognitive behavior. While this model has been well characterized in male subjects, the effects of CIE in females and long-term effects that persist beyond the acute withdrawal remain relatively underexplored. Here, female C57BL/6J mice were exposed to four weeks of chronic intermittent ethanol (CIE) vapor to induce dependence. Following CIE, mice were evaluated for physiological tolerance to ethanol and alterations in anxiety-like behaviors and memory processing. Using the ethanol responsivity battery (ERB) assay to assess physiological tolerance, we found blunted responsiveness to the intoxicating effects of ethanol in the CIE-exposed females, indicating heightened ethanol tolerance that persists beyond the acute withdrawal phase. A cohort underwent behavioral testing following CIE to characterize changes in anxiety-like behavior, exploration, and memory across abstinence. In early abstinence (<5 days post-CIE), CIE-exposed females showed increased exploratory behavior compared with Air controls. After one week of abstinence, CIE-exposed females displayed impaired object recognition memory. CIE-exposed females also showed increased anxiety-like behavior at protracted abstinence time points, exhibiting hyponeophagia in the novelty-suppressed feeding test at 2 weeks post-CIE. In addition, following cued fear conditioning, we found reduced extinction recall at 4 weeks post-CIE. Together, this work indicates that chronic alcohol exposure leads to increased alcohol tolerance and distinct, persistent alterations in memory and anxiety-like behavior in female mice.

Food addiction (FA) has been proposed as a phenotype sharing features with substance use disorders. Despite increasing recognition of food addiction as a behavioral phenotype with features overlapping substance use disorders, little is known about its prevalence or clinical significance among individuals with alcohol use disorder (AUD). Objective: To examine the prevalence of FA and to evaluate demographic, psychological, and alcohol-related correlates in individuals with AUD. Design, Setting, and Participants: This cross-sectional analysis included 743 adults with AUD who were either treatment seeking (Tx) (n = 534) for AUD and were enrolled in an inpatient program at the National Institutes of Health Clinical Center or not treatment-seeking (non Tx) (n = 209). Main Outcomes and Measures: FA symptoms were assessed using the Yale Food Addiction Scale, with >=2 symptoms categorized as FA in this report. Multivariable logistic regression models adjusted for age, education, and income were conducted separately within each cohort. Results: Among 743 adults with AUD, 238 (32.1%) met criteria for FA symptoms, with similar prevalence among Tx (32.6%) and nonTx (30.6%) participants despite marked differences in clinical characteristics. Across both cohorts, FA was independently associated with higher body mass index, greater psychological distress, and greater alcohol dependence severity. Childhood trauma and poorer sleep quality were additionally associated with FA among treatment-seeking participants, whereas alcohol-related measures differed according to treatment status. Conclusions and Relevance: FA was common among adults with AUD and was associated with greater psychological, behavioral, and metabolic burden regardless of treatment-seeking status. These findings suggest that FA identifies a clinically meaningful subgroup of individuals with AUD who may benefit from more comprehensive assessment and integrated treatment approaches.

Cocaine use disorder remains a critical public health concern with limited treatment options. Astrocytes are increasingly recognized as active regulators of neurotransmission and are emerging as important contributors to addiction neurobiology. Here, we examined how chemogenetic activation of astrocytic Gq signaling within the ventral tegmental area (VTA) influences cocaine-associated behaviors in drug-naive and cocaine-experienced rats. Using a subthreshold dose of cocaine in a conditioned place preference (CPP) paradigm, we found that VTA astrocyte Gq activation facilitated the acquisition of cocaine CPP in drug-naive rats but suppressed the development of cocaine CPP in cocaine-experienced rats. Additionally, chemogenetic activation of VTA astrocyte Gq signaling suppressed voluntary cocaine intake in a self-administration paradigm. Together, these findings demonstrate that VTA astrocyte Gq signaling shapes cocaine-associated behaviors in a drug history-dependent manner, highlighting VTA astrocytes as a potential therapeutic target in cocaine use disorder.

Following cocaine self-administration, male and female rats received daily semaglutide during a 30-day abstinence period before cue- and cocaine-induced reinstatement tests. Semaglutide attenuated cue-induced reinstatement and cocaine-induced stereotypy, although operant responding was elevated following cocaine priming. These findings support further investigation of semaglutide as a treatment for cocaine use disorder.

Background: Pavlovian-to-instrumental transfer (PIT) paradigms assess how environmental cues influence instrumental behaviour. Our previous research linked PIT to alcohol use disorder (AUD) and high-risk drinking using monetary rewards during learning. To better capture alcohol-related cue effects, we developed a PIT paradigm delivering trial-by-trial alcohol and juice rewards alongside monetary rewards, to examine alcohol-specific and general PIT effects in parallel. Methods: Seventy-five participants with AUD and ninety-five controls completed the task during functional magnetic resonance imaging. Alcohol-specific PIT was defined as increased alcohol choices during presentation of alcohol-associated versus juice-associated cues. General PIT was defined as increased response vigor during gain- versus loss-associated cues. Behavioural and neural associations with AUD status and AUDIT scores from baseline through one-year follow-up were examined. Results: Participants with AUD showed stronger alcohol-specific PIT effect than controls. Alcohol-specific PIT was positively associated with baseline AUDIT scores and with AUDIT scores across the one-year follow-up. Alcohol cues elicited stronger anterior insula responses, and region-of-interest analysis showed greater left amygdala responses to alcohol versus juice cues in AUD compared with controls. In contrast, general PIT showed a negative association with AUDIT but no association with AUD status. In the general PIT, no AUD-related neural differences were observed. Conclusions: These findings suggest that alcohol-specific PIT captures a clinically meaningful mechanism of cue-driven alcohol seeking that is distinct from generalized motivational transfer, supporting its potential utility as a mechanistic marker in AUD.

Fentanyl-related overdose deaths now commonly involve non-injection routes, yet preclinical opioid self-administration is modeled predominantly intravenously. Here we establish an oral fentanyl self-administration procedure in male and female inbred C57BL/6 and outbred CD1 mice that measures volitional intake, cue-driven seeking, extinction, and relapse. Mice self-administered oral fentanyl (70 {micro}g/mL) on a fixed-ratio 1 schedule across fifteen 3-hour sessions, followed by ten extinction sessions and a cued reinstatement test. A separate cohort underwent between-session dose thresholding across a quarter-log series from 222 to 22 {micro}g/mL. Seventy-five percent of mice acquired self-administration, with similar rates across genetic background and sex. Responding increased as fentanyl concentration fell, indicating dose-sensitivity toward a preferred drug level. C57BL/6 mice escalated intake and lever pressing across sessions, responded persistently early in extinction before declining, and reinstated pressing to a conditioned cue. CD1 mice consumed high levels from the outset with limited escalation and showed neither extinction nor cued reinstatement of pressing, but shortened their reward-port approach latency when cues returned. This shows that lever presses alone would have misclassified them as weakly conditioned. A composite severity score summing seven components of fentanyl-use risk varied continuously rather than splitting into high and low groups, even among inbred mice. Sex differences were largely confined to C57BL/6 mice, in which females showed stronger cue association and higher severity scores than males. These results reveal separable escalation-prone and relapse-prone phenotypes that track genetic background. Protocols, hardware specifications, and analysis code are openly available, lowering the barrier to adopting oral fentanyl self-administration.

Binge alcohol drinking is a public health concern that can dramatically increase the risk for development of alcohol use disorder (AUD). Continued alcohol drinking in the face of negative consequences is another key feature of AUD. A better understanding of the neural circuitry that regulates these behaviors could provide insight as to novel treatments for AUD. Serotonin is a neurotransmitter that has been implicated in alcohol consumption in both human studies and animal models. The orbitofrontal cortex (OFC) is a brain region that both receives serotonergic input from the dorsal raphe and has been implicated in AUD. However, how volitional alcohol consumption impacts serotonin signaling within the OFC and how this contributes to alcohol related behaviors is unknown. Here, we show that a history of alcohol consumption alters the ability of 5-HT to hyperpolarize OFC pyramidal neurons in mice and monkeys. Consistent with this, a history of binge alcohol consumption decreases the expression of the 5-HT1A but not 5-HT2A receptor in the OFC from mice. Next, we show that deletion of the 5-HT1A receptor from the OFC increased alcohol intake and preference in male, but not female mice. Finally, we found that 5-HT1A receptor deletion led to increased quinine-adulterated alcohol intake, a measure of aversion-resistant drinking, in both male and female mice. Altogether, we identified serotonin signaling in the OFC as key target for modulation of binge and compulsive alcohol consumption.

Alcohol misuse is a leading cause of preventable death worldwide. Chronic alcohol is associated with disrupted circadian rhythms, yet molecular mechanisms linking circadian rhythm dysregulation and alcohol consumption are poorly understood. Current FDA-approved treatments for alcohol use disorder (AUD) do not target molecular rhythms or sleep-wake cycles. Mammalian circadian rhythms are regulated by transcription-translation feedback loops that regulate expression of 'clock genes' (e.g., Arntl encoding for BMAL1). Both human and rodent studies demonstrate associations between clock gene variants and changes in reward-seeking behavior. Evidence suggests astrocytes, non-neuronal brain cells with cell-autonomous rhythms, may regulate both circadian rhythms and reward. In the nucleus accumbens (NAc), a region responsible for modulating alcohol- and reward-related behavior, over 43% of the astrocyte transcriptome is expressed rhythmically. However, no studies to date have investigated roles of NAc astrocyte rhythmicity in regulating alcohol drinking. We used AAV8-Gfap-Cre to functionally ablate molecular rhythms in NAc astrocytes of BMAL1 floxed mice. Two-bottle choice (2BC), drinking-in-the-light (DIL), and drinking-in-the-dark (DID) assessed alcohol drinking. Behavioral assays included locomotor response to novelty, sucrose preference, and social interaction. Disrupting molecular clock function in NAc astrocytes increased binge-like drinking during both DIL and DID paradigms (d = 1.44), but not with any other drinking paradigm or behavior. This study carves out a unique role for astrocytes in controlling the temporal organization of reward circuitry and susceptibility to binge-drinking. Future studies will investigate clock-controlled astrocyte mechanisms, such as glutamate uptake and ATP release, that may underlie binge-like drinking behavior.

In the KARE trial, 96 adults with severe alcohol use disorder, abstinent following detoxification, were randomised in a 2x2 factorial design to 3 weekly infusions of ketamine (0.8 mg/kg) or saline, each combined with mindfulness-based psychological support (PS) or alcohol psychoeducation (PE). We re-expressed the trial data on endpoints acceptable to regulators and compared the most and least intensive arms. Across pooled weeks 17-24, ketamine plus PS gave 78.5% versus 57.8% days abstinent (difference, 20.7 percentage points; P = .032); adjusted for baseline, the difference at weeks 21-24 was 26.9 percentage points (P = .011). At weeks 21-24, 50.0% versus 26.1% had no heavy drinking days (P = .127). Relative reductions in heavy drinking days were 55% in KARE, against 25%, -17%, 46% and 35% reported for naltrexone, exenatide, semaglutide and pemvidutide. These post hoc differences, measured 4 to 6 months after a 4 week course ended, are of magnitude similar to agents requiring continuous administration.

Genetics shape cocaine behavior and abuse liability, but the underlying neurophysiological effects remain understudied. In male C57BL/6J, B6129SF2/J, and DO/J mice, we report conserved and divergent cocaine induced neuroplasticity in the accumbens shell following 5 days of cocaine and 10 to 14 days of abstinence.

Rationale: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have attracted interest for their effects on motivational processes beyond satiation and weight loss, including motivation for drug rewards. Reward-predictive cues can acquire motivational value and promote food- and drug-seeking, raising the possibility that GLP-1RAs affect intake by altering cue-motivated behavior. Preclinical studies report reduced food intake and responding for drug rewards following GLP-1RA treatment. However, many preclinical studies have used acute treatment; whereas, clinically, GLP1-RAs are administered as chronic treatments with dose escalation to mitigate adverse effects. Objectives: Using a modified Pavlovian conditioned approach (PavCA) paradigm, we directly compared the effects of acute and chronic semaglutide treatment on conditioned approach behavior elicited by cues predicting different magnitudes of palatable food reward in male and female rats. Results: Although both treatment regimens reduced body weight relative to vehicle treatment, chronic semaglutide increased, whereas acute semaglutide decreased, sign-tracking toward reward-associated cues. Rats exhibited greater sign-tracking toward cues predicting large versus small rewards, but semaglutide did not differentially alter this reward-magnitude effect. Acutely treated rats consumed fewer reward pellets and exhibited less food-cup activity during non-cue periods. These findings suggest that nonspecific behavioral suppression or malaise may have contributed to reduced responding after acute treatment. Conclusions: The effects of semaglutide on cue-motivated behavior depend on the treatment regimen. Acute-treatment studies should be interpreted cautiously because adverse or nonspecific effects may contribute to apparent reductions in motivation.

Alcohol use disorders are heritable, and large-scale genome-wide association studies have recently identified novel genetic loci that are correlated with alcohol consumption and problematic alcohol use. One such gene is Slc39a8, which encodes the ion transporter ZIP8, responsible for cellular import of zinc and other metals. Slc39a8 is highly pleiotropic, and a common missense variant has been associated with decreased problematic alcohol use. Here, we used Slc39a8 heterozygous (HET) knockout mice and their wild type (WT) littermates to characterize the effects of reduced gene function on two models of voluntary alcohol consumption (drinking in the dark and intermittent access two-bottle choice), and anxiety- and depression-like behavior. We found that HET mice consumed less alcohol than WT in the intermittent access two-bottle choice procedure. No evidence was found for genotypic differences in baseline locomotor activity, anxiety-like, or depression-like behavior in the open field and forced swim tests. Slc39a8 mRNA expression and alcohol metabolism experiments confirmed decreased brain expression of Slc39a8 in HET mice and unchanged alcohol metabolism. Basal and post-alcohol measurement of zinc levels showed that HET mice after ethanol exposure had lower zinc concentrations in the liver and higher concentrations in blood than WT animals. Analysis of the spatial distribution of multiple trace metals in the brains of naive Slc39a8 HET and WT mice using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) showed region-specific genotypic differences in levels of zinc and iron. These results provide evidence for a direct role of Slc39a8 in ethanol consummatory behavior that does not appear to be due to metabolism, affective state, or locomotor activity. Moreover, we confirm that this animal model shows tissue- and brain region-specific alterations in zinc levels, highlighting potential mechanisms for future study.

Background: Deficits in inhibitory control are considered a central feature of alcohol use disorder (AUD), yet behavioral and neuroimaging findings have been inconsistent. One potential explanation is the marked heterogeneity of AUD, which encompasses multiple symptom dimensions that may differ in their underlying neurocognitive mechanisms. In this study, we investigated whether behavioral and neural markers of inhibitory control are associated with specific DSM-5 AUD symptom domains. Methods: A total of 589 participants (432 with non-treatment seeking AUD, 157 controls) completed a Stop-Signal Task (SST) during fMRI. Associations between DSM-5 symptom domains (impaired control over alcohol use, risky use, social problems, physical dependence) and SST performance, inhibition-related brain activation, and alcohol consumption were examined. Real-life drinking behavior was additionally assessed over 12 months using ecological momentary assessment (EMA). Results: Greater impaired control symptom severity was associated with poorer performance on go trials and diminished post-error slowing during SST. At the neural level, higher impaired control symptom severity was associated with reduced activation across fronto-insular, parietal, cingulate, supplementary motor, and cerebellar regions. In contrast, other symptom domains showed little to no associations with inhibition-related behavioral or neural measures. Higher impaired control symptom severity was associated with greater alcohol consumption across questionnaire-based and EMA-based assessments. Conclusions: In this large cohort, altered behavioral performance and recruitment of inhibition-related brain regions in the SST was selectively linked to impaired control symptoms. These findings highlight the importance of symptom-based approaches for understanding heterogeneity in addiction and may inform the development of more targeted interventions.

Pavlovian conditioned stimuli can compromise goal-directed behavior, particularly when they conflict with the required instrumental response. Previous research linked an increased impact of such Pavlovian-to-instrumental transfer (PIT) interference to risky drinking and alcohol dependence. However, it remained unclear whether the observed behavioral and neural alterations generalize to the substantially larger population of non-treatment-seeking individuals with predominantly mild-to-moderate alcohol use disorder (AUD) and to other substances like nicotine. We therefore studied 200 participants from the general population who were stratified by AUD and smoking status before completing a single-lever PIT task during functional imaging. PIT interference was measured as the difference in error rates between incongruent PIT trials, characterized by conflicts of Pavlovian and instrumental stimuli, and congruent trials. Associations with AUD and smoking status, as well as dimensional associations of behavioral PIT interference and neural responses to PIT conflicts with substance-related measures, were examined. As expected, participants with AUD showed greater PIT interference and reduced conflict-related activation in the lateral prefrontal, dorsomedial prefrontal, and anterior cingulate cortex than participants without AUD. The magnitude of these alterations also correlated with higher AUD severity and alcohol consumption, while being independent of smoking status and other smoking-related measures. These findings suggest that enhanced PIT interference generalizes to the broader AUD population but may not extend to other substances like nicotine. They further implicate a reduced recruitment of prefrontal control networks during PIT conflicts as a potential mechanism underlying enhanced PIT interference in AUD and its association with clinically relevant outcome measures.

Objective To evaluate the association of early addiction consultation with withdrawal pharmacotherapy and complications in hospitalized patients with alcohol withdrawal. Methods Retrospective single-center cohort of adult hospitalizations with alcohol withdrawal (diagnosis code or CIWA-Ar [&ge;]10 within 24 hours) from July 2020 to January 2026. Exposure was an addiction consult service order within 24 hours of arrival, compared with no or later consultation. Primary outcomes were intensive care unit (ICU) transfer after the first 24 hours and delirium tremens or withdrawal seizure not present on admission. Process outcomes included phenobarbital and thiamine administration within 24 hours and benzodiazepine dose in the first 48 hours. Secondary outcomes included length of stay and 30-day death or return to hospital. Results Of 4,663 hospitalizations, 1,379 (29.6%) received early consultation. After adjustment, early consultation was associated with lower odds of ICU transfer (odds ratio [OR] 0.73; 95% CI 0.54-0.99) and fewer episodes of delirium tremens (risk difference -1.09 per 100; -1.45 to -0.73), with no significant difference in withdrawal seizure. Early consultation was associated with phenobarbital (OR 1.57; 1.32-1.86) and thiamine (OR 1.23; 1.07-1.41) within 24 hours, higher 48-hour lorazepam-equivalent dose (ratio of geometric means 1.44; 1.32-1.57), shorter stays (ratio 0.92; 0.88-0.97), and lower odds of 30-day death or return to hospital (OR 0.78; 0.66-0.91). Conclusions Early addiction consultation was associated with earlier, more intensive withdrawal pharmacotherapy, lower odds of ICU transfer, and fewer episodes of delirium tremens, although the complication associations were sensitive to cohort definition.