Prefrontal and striatal dopamine D/D receptors correlate with fMRI BOLD activation during stopping.

D-like dopamine receptors in animals and humans have been shown to be linked to impulsive behaviors that are highly relevant for several psychiatric disorders. Here, we investigate the relationship between the fronto-striatal D/D dopamine receptor availability and response inhibition in a selected population of healthy OPRM1 G-allele carriers. Twenty-two participants successively underwent blood-oxygen level dependent functional magnetic resonance imaging (fMRI) while performing a stop-signal task and a separate positron emission tomography (PET) scan.

Efficacy of Varenicline in Patients With Severe Alcohol Dependence: A Pilot Double-Blind Randomized and Controlled Study.

Purpose/background: Varenicline has proven its efficacy in the treatment of nicotine dependence, and there is also evidence that it could be helpful in the treatment of alcohol dependence. In our pilot study, we investigated the feasibility and acceptability of varenicline for the treatment of a population of patients with severe alcohol dependence and multiple somatic comorbidities after alcohol detoxification.

Methods/procedures: We conducted a phase II, double-blind, placebo-controlled randomized trial of daily oral varenicline versus a placebo in alcohol-dependent men and women after alcohol detoxification (n = 28).

Acute effect of intravenously applied alcohol in the human striatal and extrastriatal D /D dopamine system.

Investigations on the acute effects of alcohol in the human mesolimbic dopamine D /D receptor system have yielded conflicting results. With respect to the effects of alcohol on extrastriatal D /D dopamine receptors no investigations have been reported yet. Therefore we applied PET imaging using the postsynaptic dopamine D /D receptor ligand [ F]fallypride addressing the question, whether intravenously applied alcohol stimulates the extrastriatal and striatal dopamine system.

Association of VMAT2 gene polymorphisms with alcohol dependence.

Alcohol-related diseases cause significant harm in the western world. Up to 65 % of the phenotypic variance is genetically determined. Few candidate genes have been identified, comprising ADH4, ALDH2, COMT, CRHR1, DAT (SLC6A3), GABRA2 and MAOA.

Possible association between OPRM1 genetic variance at the 118 locus and alcohol dependence in a large treatment sample: relationship to alcohol dependence symptoms.

Background: Several lines of evidence from previous research indicate that opioid receptors play an important role in ethanol reinforcement and alcohol dependence (AD) risk. Conflicting results were reported on the role of the mu-opioid receptor (OPRM1) polymorphism A118G (Asn40Asp, rs1799971) in the development of alcoholism.

Methods: We investigated a total number of 1,845 alcohol-dependent subjects recruited from inpatient facilities in Germany and 1,863 controls for the mu-opioid receptor (OPRM1) polymorphism using chi-square statistics.

Broad disruption of brain white matter microstructure and relationship with neuropsychological performance in male patients with severe alcohol dependence.

Aims: In the last years, refined magnetic resonance diffusion tensor imaging (DTI) methods have become available to study microstructural alterations in the human brain. We investigated to what extent white matter tissue abnormalities are present in male patients after chronic, excessive alcohol consumption and if these alterations are correlated with measures of alcohol consumption and neuropsychological performance.

Methods: Twenty-four detoxified adult male patients with severe alcohol dependence and 23 healthy male control subjects were included in the study.

Dopamine D2/D3 receptor availability and venturesomeness.

The construct of impulsivity is considered as a major trait of personality. There is growing evidence that the mesolimbic dopamine system plays an important role in the modulation of impulsivity and venturesomeness, the two key components within the impulsivity-construct. The aim of the present study was to explore an association between trait impulsivity measured with self-assessment and the dopaminergic neurotransmission as measured by positron emission tomography (PET) in a cohort of healthy male subjects.

Impulsiveness and venturesomeness in German smokers.

Introduction: Cigarette smoking is a behavior, which is influenced by genetic, demographic, and psychological factors. A large body of research has examined the association of cigarette smoking variables with individual differences in personality traits. The aim of the current study was to replicate the findings of higher self-reported impulsivity in smokers compared with never-smokers in a German sample using Eysenck´s construct of impulsivity.

Risk gene variants for nicotine dependence in the CHRNA5-CHRNA3-CHRNB4 cluster are associated with cognitive performance.

Recent studies strongly support an association of the nicotinic acetylcholine receptor gene cluster CHRNA5-CHRNA3-CHRNB4 with nicotine dependence (ND). However, the precise genotype-phenotype relationship is still unknown. Clinical and epidemiological data on smoking behavior raise the possibility that the relevant gene variants may indirectly contribute to the development of ND by affecting cognitive performance in some smokers who consume nicotine for reasons of "cognition enhancement.

Association of ADH4 genetic variants with alcohol dependence risk and related phenotypes: results from a larger multicenter association study.

Genetic variants of the alcohol-metabolizing enzyme ADH4, located on chromosome 4q22-4q23, have been related to alcohol dependence (AD) risk in previous research. The aim of this association study in a large multicenter sample of alcohol-dependent individuals and controls is to confirm ADH4 single nucleotide polymorphism (SNP) and haplotype association with AD and relevant related phenotypes. One thousand, six hundred and twenty-two (1622) inpatient subjects and 1469 control subjects with DSM-IV.

Disturbed structural connectivity is related to inattention and impulsivity in adult attention deficit hyperactivity disorder.

Inattention and impulsivity are the most prominent clinical features of attention deficit hyperactivity disorder (ADHD) in adulthood. Structural and functional neuroimaging studies of subjects with ADHD have demonstrated abnormalities in several brain areas, including fronto-striatal and fronto-cerebellar networks. Mostly, these studies were based on volumetric measurements and have been conducted in children.

Severity of dependence modulates smokers' neuronal cue reactivity and cigarette craving elicited by tobacco advertisement.

Smoking-related cues elicit craving and mesocorticolimbic brain activation in smokers. Severity of nicotine dependence seems to moderate cue reactivity, but the direction and mechanisms of its influence remains unclear. Although tobacco control policies demand a ban on tobacco advertising, cue reactivity studies in smokers so far have not employed tobacco advertisement as experimental stimuli.

Disturbed brain activation during a working memory task in drug-naive adult patients with ADHD.

Neuroimaging studies in attention-deficit/hyperactivity disorder (ADHD) have shown abnormalities in several brain areas including the frontostriatal circuitry and were mostly conducted in children and adolescents. We investigated 30 never-medicated adult ADHD patients (16 males) and 30 matched healthy control individuals. Functional magnetic resonance imaging was acquired during a working memory paradigm (n-back).

Human dopamine receptor D2/D3 availability predicts amygdala reactivity to unpleasant stimuli.

Dopamine (DA) modulates the response of the amygdala. However, the relation between dopaminergic neurotransmission in striatal and extrastriatal brain regions and amygdala reactivity to affective stimuli has not yet been established. To address this issue, we measured DA D2/D3 receptor (DRD2/3) availability in twenty-eight healthy men (nicotine-dependent smokers and never-smokers) using positron emission tomography with [18F]fallypride.

No association of alcohol dependence with SLC6A5 and SLC6A9 glycine transporter polymorphisms.

To determine whether glycine transporter polymorphisms are associated with alcoholism, three genetic variants of SLC6A5 and two polymorphisms of SLC6A9 were genotyped in 463 German non-alcoholic controls and 644 German alcohol-dependent subjects. Association was investigated employing chi-square statistics and haplotype analysis. There was a significant association between the SLC6A5 polymorphism (rs1443547) and alcohol dependence as alcoholic individuals had a lower rate of AG-allele (chi(2) = 6.

Genome-wide association study of alcohol dependence.

Context: Alcohol dependence is a serious and common public health problem. It is well established that genetic factors play a major role in the development of this disorder. Identification of genes that contribute to alcohol dependence will improve our understanding of the mechanisms that underlie this disorder.

Low novelty seeking and high self directedness scores in alcohol-dependent patients without comorbid psychiatric disorders homozygous for the A10 allele of the dopamine transporter gene.

The gene for the human dopamine transporter DAT1 displays several polymorphisms, including a 40-bp variable number of tandem repeats (VNTR) ranging from 3 to 13 copies in the 3'-untranslated region (UTR) of the gene. Some hints for an association of certain VNTR with psychiatric disorders, behavioural problems and temperament traits have been found. This study explored possible associations between the most frequent DAT1 polymorphism, namely the A10 VNTR, and personality traits as measured by the Temperament and Character Inventory (TCI) and the NEO Five Factor Inventory (NEO-FFI) in alcohol-dependent patients (ADP).

Detection times for urinary ethyl glucuronide and ethyl sulfate in heavy drinkers during alcohol detoxification.

Aims: Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are conjugated ethanol metabolites formed in low amounts after alcohol consumption. Compared with ethanol, EtG and EtS are excreted in urine for a prolonged time, making them useful as sensitive alcohol biomarkers. This study determined the detection times for EtG and EtS in alcoholic patients undergoing alcohol detoxification.

Cannabinoid receptor 1 blocker rimonabant (SR 141716) for treatment of alcohol dependence: results from a placebo-controlled, double-blind trial.

Multiple lines of evidence suggest that the endocannabinoid system is implicated in the development of alcohol dependence. In addition, in animal models, the cannabinoid receptor 1 blocker rimonabant was found to decrease alcohol consumption, possibly by indirect modulation of dopaminergic neurotransmission. This was a 12-week double-blind, placebo-controlled, proof-of-concept study to assess the possible efficacy of the cannabinoid receptor 1 antagonist rimonabant 20 mg/d (2 x 10 mg) in the prevention of relapse to alcohol in recently detoxified alcohol-dependent patients.

Association of low striatal dopamine d2 receptor availability with nicotine dependence similar to that seen with other drugs of abuse.

Objective: All drugs of abuse induce a phasic dopamine release within the striatum that does not undergo habituation. Prolonged substance consumption impairs the natural function of the mesolimbic dopamine system, as shown by a decrease in the availability of striatal dopamine 2 (D(2)) receptors in patients suffering from cocaine, heroin, amphetamine, and alcohol dependence. However, it is unclear whether similar changes can also be observed in heavy-smoking nicotine-dependent smokers.

Biomarkers to disclose recent intake of alcohol: potential of 5-hydroxytryptophol glucuronide testing using new direct UPLC-tandem MS and ELISA methods.

Aims: This study compared two new methods for direct determination of 5-hydroxytryptophol glucuronide (GTOL) in urine, a biomarker for detection of recent alcohol consumption.

Methods: Urine samples were collected from ten alcoholic patients during recovery from intoxication. A direct injection ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for measurement of the urinary GTOL to 5-hydroxyindoleacetic acid (5-HIAA) ratio, and an ELISA assay for direct measurement of GTOL, were used.

Tiagabine does not attenuate alcohol-induced activation of the human reward system.

Rationale: The rewarding effects of ethanol and other drugs of abuse are mediated by activation of the mesolimbic dopamine system. Recent neuroimaging studies in primates and humans suggest that cocaine-induced dopamine stimulation might be diminished by drugs augmenting gamma-aminobutyric acid A (GABA-A) receptor function such as the GABA transaminase inhibitor vigabatrin.

Objectives: The objective of this study was to test the property of the selective GABA transporter 1 (GAT1) inhibitor tiagabine to block ethanol-induced activation of the mesolimbic reward system in an i.