Dopaminergic Genetic Variation Influences Aripiprazole Effects on Alcohol Self-Administration and the Neural Response to Alcohol Cues in a Randomized Trial

"It's been a long time since I drank like that": A case report of binge drinking associated with aripiprazole

Aripiprazole has been linked to the development of impulse control problems (ICPs), most commonly gambling. Aripiprazole's effect on serotonergic and dopaminergic pathways has had mixed results on drinking behaviors. A male patient receiving outpatient psychiatric care presented with ongoing symptoms of depression on his current regimen of mirtazapine and gabapentin. Aripiprazole was chosen for augmentation after multiple failed trials of alternative medications. Within 3 weeks the patient discontinued the medication due to escalating binge-drinking behavior. This behavior resolved within 3 days after discontinuing aripiprazole. Individuals who engage in binge drinking demonstrate consistent impulse control deficits that are unrelated to the rewarding effects of alcohol. Aripiprazole may be related to this patient's return to binge drinking from an ICP standpoint rather than driven by alcohol cravings as other psychosocial factors remained stable throughout this time.

Brexpiprazole in patients with schizophrenia with or without substance use disorder: an observational study

Background

Partial dopamine D2 receptor agonists are used for psychotic symptoms in adults with schizophrenia spectrum disorders. Recently, interest surged for partial dopamine D2 receptor agonists in substance use disorders (SUDs). Since it is believed that SUDs decrease the efficacy of pharmacotherapy of underlying psychiatric disorders, we tested the efficacy of the partial D2 agonist brexpiprazole in patients with schizophrenia who were either comorbid with a SUD (SUD group) or not comorbid (non-SUD) to assess treatment response and the effect of brexpiprazole on substance craving in SUD.

Methods

We included patients with DSM-5/DSM-5-TR schizophrenia (using SCID-5-CV) aged 18-66 years with either comorbid SUD or non-SUD to treat with brexpiprazole 4 mg/day for 6 months during February-October 2022. Patients were assessed with the Clinical Global Impressions-Severity (CGI-S) scale, the 24-item Brief Psychiatric Rating Scale (BPRS), and the Positive And Negative Syndrome Scale (PANSS) at baseline, weekly for the first 2 months and monthly for the next four. Furthermore, we assessed substance craving in SUD with a visual analog scale for craving (VAScrav) at the same timepoints.

Results

The total sample was 86 (85 analysable) 18- to 64-year-old (mean 39.32 ± 14.09) patients with schizophrenia [51 men (59.3%) and 35 women (40.7%)], of whom 48 SUD (55.8%) (37 men and 11 women) and 38 non-SUD (44.2%) (14 men and 24 women). No serious or persistent adverse events developed over the study period, but one patient dropped out for subjective akathisia. Results indicated the main effects of time with improvements over the course of the study for CGI-S, BPRS, and PANSS in both SUD and non-SUD groups and the entire sample, and for VAScrav in SUD. Brexpiprazole was associated with similar significant improvements in both groups at the 6 month endpoint compared to baseline.

Conclusion

Treatment with brexpiprazole for 6 months improved psychotic symptoms in patients with schizophrenia, independently from whether they belonged to the SUD or the non-SUD group; hence, SUD comorbidity did not confer treatment resistance to brexpiprazole. Furthermore, in the SUD group, we observed reduced substance craving.

Consuming oral cannabidiol prior to a standard alcohol dose has minimal effect on breath alcohol level and subjective effects of alcohol

RATIONALE

Cannabidiol (CBD) is found in the cannabis plant and has garnered attention as a potential treatment for alcohol use disorder (AUD). CBD reduces alcohol consumption and other markers of alcohol dependence in rodents, but human research on CBD and alcohol is limited. It is unknown whether CBD reduces drinking in humans, and mechanisms through which CBD could impact behavioral AUD phenotypes are unknown.

OBJECTIVES

This study explores effects of oral CBD on breath alcohol level (BrAC), and subjective effects of alcohol in human participants who report heavy drinking.

METHODS

In this placebo-controlled, crossover study, participants consumed 30 mg CBD, 200 mg CBD, or placebo CBD before receiving a standardized alcohol dose. Participants were blind to which CBD dose they received at each session and completed sessions in random order. Thirty-six individuals completed at least one session and were included in analyses.

RESULTS

Differences in outcomes across the three conditions and by sex were explored using multilevel structural equation models. BrAC fell fastest in the placebo condition, followed by 30 mg and 200 mg CBD. Stimulation decreased more slowly in the 200 mg CBD condition than in placebo (b =  - 2.38, BCI [- 4.46, - .03]). Sedation decreased more slowly in the 30 mg CBD condition than in placebo (b =  - 2.41, BCI [- 4.61, - .09]). However, the magnitude of condition differences in BrAC and subjective effects was trivial.

CONCLUSIONS

CBD has minimal influence on BrAC and subjective effects of alcohol. Further research is needed to test whether CBD impacts alcohol consumption in humans, and if so, what mechanism(s) may explain this effect.

Genetic profile for dopamine signaling predicts brain functional reactivity to repetitive transcranial magnetic stimulation

Research integrating molecular and imaging data provides important insights into how the genetic profile associated with dopamine signaling influences inter-individual differences in brain functions. However, the effects of genetic variations in dopamine signaling on the heterogeneity of brain changes induced by repetitive transcranial magnetic stimulation (rTMS) still remain unclear. The current study examined the composite effects of genetic variations in dopamine-related genes on rTMS-induced brain responses in terms of the functional network connectivity and working memory performance. Healthy individuals (n = 30) participated in a randomized, double-blind, sham-controlled study with a crossover design of five consecutive days where active rTMS or sham stimulation sessions were administered over the left dorsolateral prefrontal cortex (DLPFC) of the brain. Participants were mostly women (n = 29) and genotyped for polymorphisms in the catechol-O-methyltransferase and D2 dopamine receptor genes and categorized according to their genetic composite scores: high vs. low dopamine signaling groups. Pre- and post-intervention data of resting-state functional magnetic resonance imaging and working memory performance were obtained from 27 individuals with active rTMS and 30 with sham stimulation sessions. The mean functional connectivity within the resting-state networks centered on the DLPFC increased in the high dopamine signaling group. Working memory performance also improved with rTMS in the high dopamine signaling group compared to that in the low dopamine signaling group. The present results suggest that genetic predisposition to higher dopamine signaling may be a promising neurobiological predictor for rTMS effects on cognitive enhancement.Trial registration: ClinicalTrials.gov (NCT02932085).

The pharmacogenetics of the new-generation antipsychotics - A scoping review focused on patients with severe psychiatric disorders

Exploring the possible correlations between gene variations and the clinical effects of the new-generation antipsychotics is considered essential in the framework of personalized medicine. It is expected that pharmacogenetic data will be useful for increasing the treatment efficacy, tolerability, therapeutic adherence, functional recovery, and quality of life in patients with severe psychiatric disorders (SPD). This scoping review investigated the available evidence about the pharmacokinetics, pharmacodynamics, and pharmacogenetics of five new-generation antipsychotics, i.e., cariprazine, brexpiprazole, aripiprazole, lumateperone, and pimavanserin. Based on the analysis of 25 primary and secondary sources and the review of these agents' summaries of product characteristics, aripiprazole benefits from the most relevant data about the impact of gene variability on its pharmacokinetics and pharmacodynamics, with significant consequences on this antipsychotic's efficacy and tolerability. The determination of the CYP2D6 metabolizer status is important when administering aripiprazole, either as monotherapy or associated with other pharmacological agents. Allelic variability in genes encoding dopamine D2, D3, and serotonin, 5HT2A, 5HT2C receptors, COMT, BDNF, and dopamine transporter DAT1 was also associated with different adverse events or variations in the clinical efficacy of aripiprazole. Brexpiprazole also benefits from specific recommendations regarding the CYP2D6 metabolizer status and the risks of associating this antipsychotic with strong/moderate CYP2D6 or CYP3A4 inhibitors. US Food and Drug Administration (FDA) and European Medicines Agency (EMA) recommendations about cariprazine refer to possible pharmacokinetic interactions with strong CYP3A4 inhibitors or inducers. Pharmacogenetic data about cariprazine is sparse, and relevant information regarding gene-drug interactions for lumateperone and pimavanserin is yet lacking. In conclusion, more studies are needed to detect the influence of gene variations on the pharmacokinetics and pharmacodynamics of new-generation antipsychotics. This type of research could increase the ability of clinicians to predict favorable responses to specific antipsychotics and to improve the tolerability of the treatment regimen in patients with SPD.

Off-label and investigational drugs in the treatment of alcohol use disorder: A critical review

Compounds known to be successful in the treatment of alcohol use disorder include the aversive agent, Disulfiram, the glutamatergic NMDA receptor antagonist, Acamprosate, and the opioid receptor antagonists, Naltrexone and Nalmefene. Although all four are effective in maintaining abstinence or reduction of alcohol consumption, only a small percentage of patients receive pharmacological treatment. In addition, many other medications have been investigated for their therapeutic potential in the treatment of alcohol use disorder. In this review we summarize and compare Baclofen, Gabapentin, Topiramate, Ondansetron, Varenicline, Aripiprazole, Quetiapine, Clozapine, Antidepressants, Lithium, Neuropeptide Y, Neuropeptide S, Corticotropin-releasing factor antagonists, Oxytocin, PF-05190457, Memantine, Ifenprodil, Samidorphan, Ondelopran, ABT-436, SSR149415, Mifepristone, Ibudilast, Citicoline, Rimonabant, Surinabant, AM4113 and Gamma-hydroxybutyrate While some have shown promising results in the treatment of alcohol use disorder, others have disappointed and should be excluded from further investigation. Here we discuss the most promising results and highlight medications that deserve further preclinical or clinical study. Effective, patient-tailored treatment will require greater understanding provided by many more preclinical and clinical studies.

Effects of pharmacological and genetic regulation of COMT activity in alcohol use disorder: a randomized, placebo-controlled trial of tolcapone

Alcohol Use Disorder (AUD) is characterized by loss of control over drinking. Behavioral control is mediated, in part, by cortical dopamine signaling. Inhibition of catechol-O-methyltransferase (COMT), the enzyme primarily responsible for cortical dopamine inactivation, may increase cortical dopamine, especially among individuals with genetically mediated lower dopaminergic tone, such as COMT rs4680 (val158met) val-allele homozygotes. This study was a randomized, placebo-controlled, pharmacogenetic trial of the COMT inhibitor tolcapone. Ninety non-treatment-seeking AUD individuals were prospectively genotyped for rs4680 and randomized to tolcapone (200 mg t.i.d.) or placebo for 8 days. At baseline and on day 7, peripheral COMT activity was assayed, and participants completed an fMRI alcohol cue-reactivity task; on day 8, they completed a bar-lab paradigm. Primary outcomes were: (1) natural drinking during the medication period; (2) alcohol self-administration in the bar lab; and (3) alcohol cue-elicited cortical (right inferior frontal gyrus [rIFG]) and ventral striatal activation. At baseline, the rs4680 val-allele had an additive effect on COMT activity. Tolcapone, relative to placebo, reduced COMT activity in all genotype groups. COMT genotype moderated tolcapone's effect on drinking during the medication period and in the bar lab, such that tolcapone, relative to placebo, reduced drinking only among val-allele homozygotes. Tolcapone did not affect cue-elicited ventral striatal activation but reduced rIFG activation; less rIFG activation on day 7 was associated with less drinking during the medication period. Taken together, these data suggest that COMT inhibition may reduce drinking specifically among individuals genetically predisposed to excessive COMT activity and potentially low cortical dopamine tone.ClinicalTrials.gov identifier: NCT02949934 https://clinicaltrials.gov/ct2/show/NCT02949934.

A methodological checklist for fMRI drug cue reactivity studies: development and expert consensus

Cue reactivity is one of the most frequently used paradigms in functional magnetic resonance imaging (fMRI) studies of substance use disorders (SUDs). Although there have been promising results elucidating the neurocognitive mechanisms of SUDs and SUD treatments, the interpretability and reproducibility of these studies is limited by incomplete reporting of participants' characteristics, task design, craving assessment, scanning preparation and analysis decisions in fMRI drug cue reactivity (FDCR) experiments. This hampers clinical translation, not least because systematic review and meta-analysis of published work are difficult. This consensus paper and Delphi study aims to outline the important methodological aspects of FDCR research, present structured recommendations for more comprehensive methods reporting and review the FDCR literature to assess the reporting of items that are deemed important. Forty-five FDCR scientists from around the world participated in this study. First, an initial checklist of items deemed important in FDCR studies was developed by several members of the Enhanced NeuroImaging Genetics through Meta-Analyses (ENIGMA) Addiction working group on the basis of a systematic review. Using a modified Delphi consensus method, all experts were asked to comment on, revise or add items to the initial checklist, and then to rate the importance of each item in subsequent rounds. The reporting status of the items in the final checklist was investigated in 108 recently published FDCR studies identified through a systematic review. By the final round, 38 items reached the consensus threshold and were classified under seven major categories: 'Participants' Characteristics', 'General fMRI Information', 'General Task Information', 'Cue Information', 'Craving Assessment Inside Scanner', 'Craving Assessment Outside Scanner' and 'Pre- and Post-Scanning Considerations'. The review of the 108 FDCR papers revealed significant gaps in the reporting of the items considered important by the experts. For instance, whereas items in the 'General fMRI Information' category were reported in 90.5% of the reviewed papers, items in the 'Pre- and Post-Scanning Considerations' category were reported by only 44.7% of reviewed FDCR studies. Considering the notable and sometimes unexpected gaps in the reporting of items deemed to be important by experts in any FDCR study, the protocols could benefit from the adoption of reporting standards. This checklist, a living document to be updated as the field and its methods advance, can help improve experimental design, reporting and the widespread understanding of the FDCR protocols. This checklist can also provide a sample for developing consensus statements for protocols in other areas of task-based fMRI.

Initial Study on COMT and DRD2 Gene Polymorphisms as Well as the Influence of Temperament and Character Trait on the Severity of Alcohol Craving in Alcohol-Dependent Patients

The main aim of this work was to determine the impact of COMT and DRD2 gene polymorphisms together with temperament and character traits on alcohol craving severity alcohol-dependent persons. The sample comprised of 89 men and 16 women (aged 38±7). For the sake of psychological assessment various analytic methods have been applied like the Short Alcohol Dependence Data Questionnaire (SADD), Penn Alcohol Craving Scale (PACS) or Temperament and Character Inventory (TCI) test. The SNP polymorphism of the analyzed genes was determined by Real Time PCR test. The results showed, that the COMT polymorphismmay have an indirected relationship with the intensity and changes in alcohol craving during abstinence. The DRD2 receptor gene polymorphisms are related with the intensity of alcohol craving. It seems that the character traits like “self-targeting”, including “self-acceptance”, are more closely related to the severity of alcohol craving and polymorphic changes in the DRD2 receptor than temperamental traits. Although this is a pilot study the obtained results appeared to be promising and clearly indicate the link betweengene polymorphisms alcohol craving and its severity.

Methylation quantitative trait locus rs5326 is associated with susceptibility and effective dosage of methadone maintenance treatment for heroin use disorder

RATIONALE

Opioid use disorder is a complicated brain disease with high heritability. The underlying mechanisms of the genetic underpinnings in the susceptibility and treatment response of opioid use disorder remain elusive.

OBJECTIVES

To reveal the potential associations of genotypes and gene methylations of dopaminergic system genes, as well as roles of them in opioid use disorder. In the present study, we detected the DNA methylation in the promoter regions of five representative dopaminergic system genes (DRD1, DRD2, SLC6A3, TH, and COMT) between 120 patients with heroin use disorder in methadone maintenance treatment (MMT) program and 111 healthy controls. The associations of 25 SNPs in the above genes and methylation of 237 CpG sites, known as methylation quantitative trait loci (mQTLs), were determined. Then, the correlations of the above mQTLs and traits of heroin use disorder were analyzed in a sample set of 801 patients with heroin use disorder and 930 healthy controls.

RESULTS

Our results demonstrated that several mQTLs in the DRD1 and DRD2 genes were identified both in the heroin use disorder and healthy control groups. Interestingly, rs4867798-CpG_174872884 and rs5326-CpG_174872884 in the DRD1 gene were the unique SNP-CpG pairs in the patients with heroin use disorder. Furthermore, mQTL rs5326 was associated with the susceptibility and effective dosage of MMT for heroin use disorder, and demonstrated allele-specific correlation with the expression of the DRD1 gene in the human caudate.

CONCLUSIONS

Our findings suggest that some mQTLs may be associated with traits of opioid use disorder by implicating the DNA methylation and gene expression.

Association between polymorphism in gene related to the dopamine circuit and motivations for drinking in patients with alcohol use disorder

The development of alcohol use disorder (AUD) is influenced by genetic, psychological, and social factors. However, the identification of the load of each of these factors and the association between them is still debatable. This study aimed to explore the load of the association between AUD and polymorphisms in genes of the dopaminergic system, as well as with drinking triggers. The study comprised 227 inpatients with AUD and 174 controls. The pattern and motivations for drinking were evaluated using the Alcohol Use Disorders Identification Test (AUDIT) and the Inventory of Drinking Situations (IDS). Analyses of genetic variation in genes encoding dopaminergic were performed using next generation sequencing. We observed an significant association between a polymorphism in DDC (rs11575457) and AUD. Positive reinforcement factors as urges/temptations to drink and pleasant emotion, in isolation, were the significantly related elements to drinking. In addition, negative (physical discomfort) and positive reinforcement factors (testing personal control; pleasant time with others) significantly reinforced the interaction with DDC genetic variant for increased odds of an individual presenting AUD. These results indicated a complex relationship between the dopaminergic system and the drug-seeking behavior profiles.

Ibudilast for alcohol use disorder: study protocol for a phase II randomized clinical trial

BACKGROUND

Alcohol use disorder (AUD) is a chronic and relapsing condition for which current pharmacological treatments are only modestly effective. The development of efficacious medications for AUD remains a high research priority with recent emphasis on identifying novel molecular targets for AUD treatment and to efficiently screen new compounds aimed at those targets. Ibudilast, a phosphodiesterase inhibitor, has been advanced as a novel addiction pharmacotherapy that targets neurotrophin signaling and neuroimmune function.

METHODS

This study will conduct a 12-week, double-blind, placebo controlled randomized clinical trial of ibudilast (50 mg BID) for AUD treatment. We will randomize 132 treatment-seeking men and women with current AUD. We will collect a number of alcohol consumption outcomes. Primary among these is percent heavy drinking days (PHDD); secondary drinking outcomes include drinks per day, drinks per drinking day, percent days abstinent, percent subjects with no heavy drinking days, and percent subjects abstinent, as well as measures of alcohol craving and negative mood. Additionally, participants will have the option to opt-in to a neuroimaging session in which we examine the effects of ibudilast on neural activation to psychosocial stress and alcohol cues. Finally, we will also collect plasma levels of proinflammatory markers, as well as subjective and biological (salivary cortisol) markers of stress response.

DISCUSSION

This study will further develop ibudilast, a safe and promising novel compound with strong preclinical and clinical safety data for AUD, and will probe biological mechanisms underlying the effects of Ibudilast on stress, neuroinflammation, and alcohol cue-reactivity and craving. If ibudilast proves superior to placebo in this study, it will set the stage for a confirmatory multi-site trial leading to FDA approval of a novel AUD treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03594435 "Ibudilast for the Treatment of Alcohol Use Disorder". Registered on 20 July 2018.

Brain region-specific neuromedin U signalling regulates alcohol-related behaviours and food intake in rodents

Albeit neuromedin U (NMU) attenuates alcohol‐mediated behaviours, its mechanisms of action are poorly defined. Providing that the behavioural effects of alcohol are processed within the nucleus accumbens (NAc) shell, anterior ventral tegmental area (aVTA), and laterodorsal tegmental area (LDTg), we assessed the involvement of NMU signalling in the aforementioned areas on alcohol‐mediated behaviours in rodents. We further examined the expression of NMU and NMU receptor 2 (NMUR2) in NAc and the dorsal striatum of high compared with low alcohol‐consuming rats, as this area is of importance in the maintenance of alcohol use disorder (AUD). Finally, we investigated the involvement of NAc shell, aVTA and LDTg in the consumption of chow and palatable peanut butter, to expand the link between NMU and reward‐related behaviours. We demonstrated here, that NMU into the NAc shell, but not aVTA or LDTg, blocked the ability of acute alcohol to cause locomotor stimulation and to induce memory retrieval of alcohol reward, as well as reduced peanut butter in mice. In addition, NMU into NAc shell decreased alcohol intake in rats. On a molecular level, we found increased NMU and decreased NMUR2 expression in the dorsal striatum in high compared with low alcohol‐consuming rats. Both aVTA and LDTg, rather than NAc shell, were identified as novel sites of action for NMU's anorexigenic properties in mice based on NMU's ability to selectively reduce chow intake when injected to these areas. Collectively, these data indicate that NMU signalling in different brain areas selectively modulates different behaviours.

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.

The dopamine transporter VNTR polymorphism moderates the relationship between acute response to alcohol and future alcohol use disorder symptoms

Alcohol use disorder (AUD) is a genetically influenced disease with peak onset in young adulthood. Identification of factors that predict whether AUD symptoms will diminish or persist after young adulthood is a critical public health need. King and colleagues previously reported that acute response to alcohol predicted future AUD symptom trajectory. Genes associated with brain dopamine signaling, which underlies alcohol's rewarding effects, might influence this finding. This study analyzed whether variation at a variable number tandem repeat polymorphism in DAT1/SLC6A3, the gene encoding the dopamine transporter, moderated the predictive relationships between acute response to alcohol and future AUD symptoms among participants enrolled in the Chicago Social Drinking Project (first two cohorts). Heavy-drinking young adults (N = 197) completed an alcohol challenge, in which acute response (liking, wanting, stimulation, and sedation) was measured. Alcohol use disorder symptoms were assessed over the following 6 years. DAT1 genotype significantly moderated the interactions between follow-up time and alcohol liking (P = 0.006) and wanting (P = 0.006) in predicting future AUD symptoms. These predictive effects were strongest among participants who carried the DAT1 9-repeat allele, previously associated with enhanced striatal dopamine tone relative to the 10-repeat allele. Exploratory analyses indicated that DAT1 effects on the relationship between alcohol liking and AUD symptoms appeared stronger for females (n = 79) than males (n = 118) (P = 0.0496). These data suggest that heavy-drinking DAT1 9-repeat allele carriers who display high alcohol-induced reward in young adulthood may be predisposed to persistent AUD symptoms and support combining genotypic and phenotypic information to predict future AUD risk.

Prospects for pharmacotherapies to treat alcohol use disorder: an update on recent human studies

PURPOSE OF REVIEW

The aim of this study was to provide an update on medication development efforts for alcohol use disorder (AUD) by reviewing recently published (past 2 years) human studies that evaluated medications' effects on alcohol-related outcomes.

RECENT FINDINGS

Forty-five publications were found suitable for this review. A variety of compounds have been tested in the past 2 years as potential pharmacological options for AUD, including medications that act on multiple targets (topiramate, aripiprazole, quetiapine), calcium channels (gabapentin), gamma-Aminobutyric acid receptors (baclofen, diazepam), glutamate receptors (ifenprodil, memantine, glycine), nicotinic acetylcholine receptors (varenicline, mecamylamine), α1 adrenergic receptors (prazosin, doxazosin), neuroendocrine pathways (oxytocin, a vasopressin receptor 1b antagonist, a ghrelin receptor inverse agonist) and others (samidorphan, ibudilast, N-acetylcysteine, citoline). Important findings and limitations regarding the effects of these medications on alcohol-related outcomes are discussed.

SUMMARY

There is a critical need to increase the armamentarium of medications for AUD. Human laboratory studies may help screen and prioritize promising targets and compounds before running large clinical trials. Given the complexity of AUD and the heterogeneity of afflicted patients, future studies should also investigate potential moderators and predictors of response to each pharmacological intervention.

Building better strategies to develop new medications in Alcohol Use Disorder: Learning from past success and failure to shape a brighter future

Alcohol Use Disorder (AUD) is a chronic disease that develops over the years. The complexity of the neurobiological processes contributing to the emergence of AUD and the neuroadaptive changes occurring during disease progression make it difficult to improve treatments. On the other hand, this complexity offers researchers the possibility to explore new targets. Over years of intense research several molecules were tested in AUD; in most cases, despite promising preclinical data, the clinical efficacy appeared insufficient to justify futher development. A prototypical example is that of corticotropin releasing factor type 1 receptor (CRF1R) antagonists that showed significant effectiveness in animal models of AUD but were largely ineffective in humans. The present article attempts to analyze the most recent venues in the development of new medications in AUD with a focus on the most promising drug targets under current exploration. Moreover, we delineate the importance of using a more integrated translational framework approach to correlate preclinical findings and early clinical data to enhance the probability to validate biological targets of interest.

Medication Development for Alcohol Use Disorder: A Focus on Clinical Studies

Compared to other medical disorders, including other brain diseases, the number of medications approved for alcohol use disorder (AUD) is very small. Disulfiram, naltrexone (oral and long-acting), and acamprosate are approved by the US Food and Drug Administration (FDA) to treat patients with AUD. These medications are also approved in other countries, including in Europe, where the European Medicines Agency (EMA) also approved nalmefene for AUD. Furthermore, baclofen was recently approved for AUD in France. These approved medications have small effect sizes, which are probably the consequence of the fact that they only work for some patients, yet a personalized approach to match the right medication with the right patient is still in its infancy. Therefore, research is needed to expand the armamentarium of medications that clinicians can use to treat their patients, as well as to better develop personalized approaches. This book chapter reviews other medications, beyond those approved by the FDA, that have shown efficacy in clinical trials, as well as medications which are still in the early stages of evaluation in human studies.