Publications by authors named "Patrick K Randall"

Background: While the opiate antagonist, naltrexone, is approved for treating alcohol use disorder (AUD), not everyone who receives the medication benefits from it. This study evaluated whether the OPRM1 SNP rs1799971 interacts with the dopamine transporter gene DAT1/SLC6A3 VNTR rs28363170 or the catechol-O-methyltransferase (COMT) gene SNP rs4680 in predicting naltrexone response.

Methods: Individuals who met DSM-IV alcohol dependence were randomly assigned to naltrexone (50 mg/d) or placebo based on their OPRM1 genotype (75 G-allele carriers and 77 A-allele homozygotes) and also genotyped for DAT1 VNTR (9 vs.

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Background: The opioid antagonist naltrexone is not efficacious for every alcohol treatment seeker. However, various individual factors, such as genetic differences and nicotine-use/smoking status, have been suggested as predictors of naltrexone response. In a randomized clinical trial, we previously reported that nicotine-use/smoking status might be a stronger predictor of naltrexone efficacy than OPRM1 A118G single nucleotide polymorphism (SNP) genotype.

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Dopamine (DA) signaling regulates many aspects of Alcohol Use Disorder (AUD). However, clinical studies of dopaminergic medications, including the DA partial agonist aripiprazole (APZ), have been inconsistent, suggesting the possibility of a pharmacogenetic interaction. This study examined whether variation in DA-related genes moderated APZ effects on reward-related AUD phenotypes.

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Background: Aspects of impulsivity have been implicated in the development, or maintenance, of alcohol use disorder (AUD). The brain dopamine system is implicated in both reward processing/memory (typically subcortical) and in brain inhibitory control mechanisms (typically cortical). Using a validated clinical laboratory paradigm, the dopamine/serotonin "stabilizing" drug, aripiprazole was evaluated in non-treatment-seeking AUD individuals based on their level of impulsivity/self-control.

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Naltrexone reduces drinking among individuals with alcohol use disorders (AUDs), but it is not effective for everyone. Variability in its effects on reward-related brain activation, genetic variation, and/or cigarette smoking may account for this mixed response profile. This randomized clinical trial tested the effects of naltrexone on drinking and alcohol cue-elicited brain activation, evaluated whether OPRM1 A118G genotype or smoking moderated these effects, and explored whether the effects of medication on cue-elicited activation predicted subsequent drinking.

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Cognitive impairments, uncontrolled drinking, and neuropathological cortical changes characterize alcohol use disorder. Dysfunction of the orbitofrontal cortex (OFC), a critical cortical subregion that controls learning, decision-making, and prediction of reward outcomes, contributes to executive cognitive function deficits in alcoholic individuals. Electrophysiological and quantitative synaptomics techniques were used to test the hypothesis that heavy drinking produces neuroadaptations in the macaque OFC.

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Alcohol (ethanol) dependence is a chronic relapsing brain disorder partially influenced by genetics and characterized by an inability to regulate harmful levels of drinking. Emerging evidence has linked genes that encode K7, K, and K2 K channels with variation in alcohol-related behaviors in rodents and humans. This led us to experimentally test relations between K channel genes and escalation of drinking in a chronic-intermittent ethanol (CIE) exposure model of dependence in BXD recombinant inbred strains of mice.

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Abused inhalants are voluntarily inhaled at high concentrations to produce intoxicating effects. Results from animal studies show that the abused inhalant toluene triggers behaviors, such as self-administration and conditioned place preference, which are commonly associated with addictive drugs. However, little is known about how toluene affects neurons within the nucleus accumbens (NAc), a brain region within the basal ganglia that mediates goal-directed behaviors and is implicated in the development and maintenance of addictive behaviors.

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Small-conductance Ca(2+)-activated K(+) (KCa2) channels control neuronal excitability and synaptic plasticity, and have been implicated in substance abuse. However, it is unknown if genes that encode KCa2 channels (KCNN1-3) influence alcohol and drug addiction. In the present study, an integrative functional genomics approach shows that genetic datasets for alcohol, nicotine, and illicit drugs contain the family of KCNN genes.

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Background: Drinking motives are thought to be important mediators of the relationship between social anxiety and alcohol use. This project evaluates whether specific drinking motives accurately reflect alcohol dependence. If so, brief questions about drinking motives could serve as valuable alcohol screening tools with socially anxious patients.

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The prefrontal cortex (PFC) is a brain region that is critically involved in cognitive function and inhibitory control of behavior, and adolescence represents an important period of continued PFC development that parallels the maturation of these functions. Evidence suggests that this period of continued development of the PFC may render it especially vulnerable to environmental insults that impact PFC function in adulthood. Experimentation with alcohol typically begins during adolescence when binge-like consumption of large quantities is common.

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Rationale: The α4β2 nicotinic acetylcholine receptor partial agonist varenicline has been reported to reduce drinking among both heavy-drinking smokers and primary alcoholics, and this effect may be related to varenicline-mediated reduction of alcohol craving. Among smokers, varenicline has been reported to modulate cigarette cue-elicited brain activation in several reward-related areas.

Objectives: This pilot study tested varenicline's effects on drinking, alcohol craving, and alcohol cue-elicited activation of reward-related brain areas among non-treatment-seeking alcohol-dependent individuals.

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Background: There remains no FDA approved medication for the treatment of cocaine dependence. Preclinical studies and early pilot clinical investigations have suggested that N-acetylcysteine (NAC) may be useful in the treatment of the disorder.

Objective: The present report assessed the efficacy of NAC in the treatment of cocaine dependence.

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Background: There is a lack of consensus in the literature as to how to define drinking outcomes in clinical trials. Typically, separate statistical models are fit to assess treatment effects on several summary drinking measures. These summary measures do not capture the complexity of drinking behavior.

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Paroxetine alone is not sufficient to decrease alcohol use in socially anxious alcoholics seeking anxiety treatment. We tested the hypothesis that adding a brief-alcohol-intervention (BI) to paroxetine would decrease alcohol use. All subjects (N=83) had a diagnosis of social anxiety disorder, endorsed drinking to cope with anxiety, were NIAAA-defined at-risk drinkers, and were randomized to either paroxetine alone, or paroxetine plus BI.

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Rationale: Many studies have reported medication effects on alcohol cue-elicited brain activation or associations between such activation and subsequent drinking. However, few have combined the methodological rigor of a randomized clinical trial (RCT) with follow-up assessments to determine whether cue-elicited activation predicts relapse during treatment, the crux of alcoholism.

Objectives: This study analyzed functional magnetic resonance imaging (fMRI) data from 48 alcohol-dependent subjects enrolled in a 6-week RCT of an investigational pharmacotherapy.

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Variation at a single nucleotide polymorphism in the μ-opioid receptor gene (OPRM1), A118G (Asn40Asp), may moderate naltrexone (NTX) effects in alcohol dependence. Both NTX and A118G variation have also been reported to affect alcohol cue-elicited brain activation. This study investigated whether sub-acute NTX treatment and A118G genotype interacted in their effects on cue-elicited activation of the ventral striatum (VS), medial prefrontal cortex (mPFC), and orbitofrontal cortex (OFC).

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Aims: Hair ethyl glucuronide (EtG) is a promising biomarker of moderate-to-heavy alcohol consumption and may have utility in detecting and monitoring alcohol use in clinical populations where alcohol use is of particular importance. This study evaluated the relationship between hair EtG and drinking in patients with liver disease.

Methods: The subjects (n = 200) were patients with liver disease who presented for care at a university medical center.

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Introduction: Prior research indicates methylphenidate (MPH) and alcohol (ethanol, EtOH) interact to significantly affect responses humans and mice. The present studies tested the hypothesis that MPH and EtOH interact to potentiate ethanol-related behaviors in mice.

Methods: We used several behavioral tasks including: drug discrimination in MPH-trained and EtOH-trained mice, conditioned place preference (CPP), rota-rod and the parallel rod apparatus.

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Background: Naltrexone is moderately effective for the treatment of alcohol dependence, but there is great individual variability. The opioid receptor (OPRM1) single nucleotide polymorphism (SNP) asn40asp has been shown to alter alcohol and naltrexone response in animals and humans. In addition, the brain opioid and dopamine systems interact and might underlie drinking and craving.

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The NR2B subunit of N-methyl d-aspartate glutamate receptors influences pharmacological properties and confers greater sensitivity to the modulatory effects of ethanol. This study examined behavioral responses to acute ethanol in a conditional knockout mouse model that allowed for a delayed genetic deletion of the NR2B subunit to avoid mouse lethality. Mice lacking the NR2B gene (knockout) were produced by mating NR2B[f/f] mice with CAMKIIa-driven tTA transgenic mice and the tetO-CRE transgenic mice.

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Article Synopsis
  • Among alcohol-dependent individuals, early alcohol abstinence can lead to alcohol withdrawal (AW), which affects GABA and glutamate signaling in the brain.
  • A study found that the combination of gabapentin and flumazenil improved response inhibition in individuals with higher levels of AW compared to those receiving placebos.
  • While the improvement in response inhibition may help reduce later drinking, these medications did not significantly affect other areas of neurocognitive performance.
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Objective: Naltrexone, an efficacious medication for alcohol dependence, does not work for everyone. Symptoms such as insomnia and mood instability that are most evident during early abstinence might respond better to a different pharmacotherapy. Gabapentin may reduce these symptoms and help prevent early relapse.

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Alcoholism treatment often encourages involvement in Alcoholics Anonymous (AA). Little provision is made for women with social phobia (SP), who have been reported to have worse outcomes in twelve-step-facilitation (TSF) relative to cognitive behavioral therapy. This study examined whether SP moderated the effects of gender for these women in TSF.

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