Konstantin Voronin

Differential brain activity in alcoholics and social drinkers to alcohol cues: relationship to craving

Using fMRI, our group previously found that after a sip of alcohol and exposure to alcohol beverage pictures, alcoholics compared to social drinkers had increased differential brain activity in the prefrontal cortex and anterior thalamus. This study extends this earlier work with several improvements including imaging the entire brain (rather than the anterior half previously) and recording craving, while the subjects viewed images within the scanner. In a Philips 1.5 T MRI scanner, 10 nontreatment-seeking alcoholics and 10 age-matched healthy social drinkers were given a sip of alcohol before viewing a 12 min randomized presentation of pictures of alcoholic beverages, nonalcoholic beverages, and two different visual control tasks. During picture presentation, changes in regional brain activity were measured in 15 transverse T2*-weighted blood oxygen level dependent slices. Subjects rated their urge to drink after each picture sequence. After a sip of alcohol, while viewing alcohol cues compared to viewing other beverage cues, the alcoholics, but not social drinkers, reported higher craving ratings and had increased activity in the prefrontal cortex and anterior limbic regions. Brain activity in the left nucleus accumbens, anterior cingulate, and left orbitofrontal cortex significantly correlated with subjective craving ratings in alcohol subjects but not in control subjects. This study suggests, as did our earlier study, that alcoholics and not social drinkers, when exposed to alcohol cues, have increased brain activity in areas that reportedly subserve craving for other addictive substances.

EFFECT OF NALTREXONE AND ONDANSETRON ON ALCOHOL CUE-INDUCED ACTIVATION OF THE VENTRAL STRIATUM IN ALCOHOL-DEPENDENT PEOPLE

CONTEXT Medication for the treatment of alcoholism is currently not particularly robust. Neuroimaging techniques might predict which medications could be useful in the treatment of alcohol dependence. OBJECTIVE To explore the effect of naltrexone, ondansetron hydrochloride, or the combination of these medications on cue-induced craving and ventral striatum activation. DESIGN Functional brain imaging was conducted during alcohol cue presentation. SETTING Participants were recruited from the general community following media advertisement. Experimental procedures were performed in the magnetic resonance imaging suite of a major training hospital and medical research institute. PATIENTS Ninety non-treatment-seeking alcohol-dependent (by DSM-IV criteria) and 17 social drinking (< 14 drinks per week) paid volunteers recruited through advertisements at an academic center. INTERVENTIONS A taste of alcohol and a series of alcohol-related pictures, neutral beverage pictures, and visual control images were provided to volunteers after 7 days of double-blind randomly assigned daily dosing with 50 mg of naltrexone (n = 23), 0.50 mg of ondansetron hydrochloride (n = 23), the combination of the 2 medications (n = 20), or matching placebos (n = 24). MAIN OUTCOME MEASURES Difference in brain blood oxygen level-dependent magnetic resonance when viewing alcohol pictures vs neutral beverage pictures with a particular focus on ventral striatum activity comparison across medication groups. Self-ratings of alcohol craving. RESULTS The combination treatment decreased craving for alcohol. Naltrexone with (P = .02) or without (P = .049) ondansetron decreased alcohol cue-induced activation of the ventral striatum. Ondansetron by itself was similar to naltrexone and the combination in the overall analysis but intermediate in a region-specific analysis. CONCLUSIONS Consistent with animal data that suggest that both naltrexone and ondansetron reduce alcohol-stimulated dopamine output in the ventral striatum, the current study found evidence that these medications, alone or in combination, could decrease alcohol cue-induced activation of the ventral striatum, consistent with their putative treatment efficacy.

Sertraline and cognitive behavioral therapy for depressed alcoholics: Results of a placebo-controlled trial

Alcoholism and depression are common disorders that frequently cooccur in the same individual. Selective serotonin reuptake inhibitors (SSRIs) are effective in the treatment of depression and also had decreased drinking in some studies of heavy drinkers and alcoholics. The reported effect of serotonergic medications on alcohol intake in depressed alcoholics has not been consistent. Most previous studies have not investigated the use of an SSRI in the context of cognitive behavioral therapy (CBT), a known efficacious treatment of both alcoholism and depression. The study presented here was a randomized placebo-controlled 12-week trial of sertraline combined with individual CBT focused on both alcoholism relapse prevention and depressive symptoms. Subjects were 82 currently depressed, actively drinking alcohol-dependent individuals. Subjects had either primary (independent) major depression (70 subjects) or substance-induced mood disorder and at least 1 first-degree relative (parent, sibling, or child) with an affective disorder (12 subjects). Depression and alcohol consumption outcomes were measured weekly over 12 weeks. Sertraline was well tolerated and all subjects had decreases in both depression and alcohol use during the study compared with baseline. Subjects who received sertraline had fewer drinks per drinking day than subjects who received placebo, but other drinking outcomes were not different between the 2 treatment groups. Treatment with sertraline was associated with less depression at the end of treatment in female subjects compared with female subjects who received placebo. Less drinking during the study was associated with improved depression outcome. The findings in this study suggest that sertraline, compared with placebo, may provide some modest benefit in terms of drinking outcome and also may lead to improved depression in female alcohol-dependent subjects. Additionally, alcohol relapse prevention CBT, delivered according to manual guidelines with modifications that provide specific attention to depression, appeared to be of benefit to subjects, although this interpretation is limited by the design of the study.

Naltrexone combined with either cognitive behavioral or motivational enhancement therapy for alcohol dependence.

Abstract: Although naltrexone has been shown to be effective in the treatment of alcohol dependence, less is known about its efficacy when combined with different behavioral therapies. Previous work has suggested that naltrexone works best when combined with weekly cognitive behavioral therapy (CBT). This study examined the efficacy of naltrexone when combined with CBT or a motivational enhancement therapy involving less patient contact. Outpatient alcoholics (N = 160) were randomly assigned to either naltrexone (50 mg/d) or placebo and either CBT (12 sessions) or motivational enhancement therapy (4 sessions), in a 4-cell design, and treated over a 12-week period. Subjects were evaluated periodically for alcohol consumption, craving, and biologic markers of drinking (carbohydrate-deficient transferrin and γ-glutamyltransferase). There was high retention and adherence to therapy and medication in the trial with no significant difference across the treatment groups. Naltrexone, independent of therapy assignment, increased the time to first relapse. However, the CBT-naltrexone group did better than the other groups on a variety of outcome measures. Fewer CBT-naltrexone-treated subjects relapsed, and those that did had both fewer, and more time between, subsequent relapses. This randomized controlled trial is consistent with previous reports about the utility of combining naltrexone with CBT. Despite being more efficient to administer, the combination of motivational enhancement therapy and naltrexone is less effective than CBT and naltrexone. Because CBT and naltrexone share common mechanisms of action, such as craving reduction and relapse prevention, these therapies are likely to be well suited to use in combination.

A clinical laboratory paradigm for evaluating medication effects on alcohol consumption: Naltrexone and nalmefene.

Opiate antagonist medications have been shown to improve alcoholism treatment, but few human laboratory-based studies investigating mechanisms for these effects have been conducted on alcohol dependent persons. The present study was designed to determine the impact of two opiate antagonists on alcohol consumption among nontreatment-seeking alcoholics (n=125) and social drinkers (n=90). Participants were randomly assigned to receive placebo, naltrexone (titrated to 50 mg/day), or nalmefene (titrated to 40 mg/day) for 8 days with an alcohol laboratory session on the final day. Alcohol consumption was monitored in the natural environment during the first 5 medication days, and during a choice consumption paradigm following a standard ‘priming’ alcohol dose in a bar–laboratory setting. Social drinkers consumed less alcohol than alcoholics during the prelab medication period and the laboratory choice consumption paradigm, and they attained lower blood alcohol levels than alcoholics following the priming drink. Both opiate antagonist medications equally reduced drinking amounts and frequency among alcoholics but not social drinkers, relative to placebo, during natural environment and bar–lab alcohol consumption evaluations. Greater medication side effects, mostly mild in nature, were observed in participants taking nalmefene. These findings demonstrate that both naltrexone and nalmefene can lead to reductions in alcohol consumption among alcoholics who are not attempting to reduce drinking. Similar laboratory paradigms may offer substantial advantages for observing these effects during evaluation of other medications as well.

The effect of aripiprazole on cue-induced brain activation and drinking parameters in alcoholics.

Because the effects of alcohol and its environmental cues on brain dopamine have been implicated in the maintenance of heavy drinking, drugs that modify dopamine might be useful in reducing drinking or promoting abstinence. The goal of the current study was to use an established brain imaging paradigm to explore the effect of aripiprazole (final dose 15 mg over a 14-day period), a dopamine stabilizer medication, on alcohol cue-induced brain activation and drinking in alcoholics. Non-treatment-seeking alcoholics were randomly assigned aripiprazole (n = 14) or identical placebo (n = 16) and reported their alcohol use while taking study medication for 14 days before an alcohol cue-induced brain functional magnetic resonance imaging study. In a Philips 3.0-T magnetic resonance imaging scanner, subjects were given a sip of alcohol before viewing a randomized presentation alcoholic- and nonalcoholic-beverage photographs while subjects rated their urge to drink. During photograph presentation, changes in regional brain activity were measured, and differences between viewing alcoholic beverage and nonalcoholic beverages were compared within and between groups. Brain activity analysis revealed increased activation for placebo-treated subjects in the right ventral striatum (P < 0.005; threshold 15 voxels), while there was a blunting of activation in this area in the aripiprazole-treated subjects. Aripiprazole-treated subjects, compared with placebo-treated subjects, also had significantly less heavy drinking during the 14-day medication period. The study provides both novel and valuable information regarding the effect of aripiprazole on cue-induced brain activation and voluntary drinking during treatment.

Interacting Effects of Naltrexone and OPRM1 and DAT1 Variation on the Neural Response to Alcohol Cues

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). Secondarily, variation at a variable number tandem repeat polymorphism in the dopamine transporter gene (DAT1/SLC6A3), which has been associated with increased reward-related activation in VS, was analyzed as a moderator of medication and A118G effects. Seventy-four non-treatment-seeking alcohol-dependent individuals, half preselected to carry at least one copy of the A118G G (Asp) allele, were randomized to NTX (50 mg) or placebo for 7 days, and performed an fMRI alcohol cue reactivity task on day 6. Region-of-interest analyses indicated no main effects of medication or A118G genotype. However, these factors interacted in their effects on OFC activation, such that, among NTX-treated individuals, G-allele carriers had less activation than A-allele homozygotes. DAT1 variation also moderated medication/A118G effects. There was a three-way interaction between medication and A118G and DAT1 genotypes on VS activation, such that, among G-allele carriers who received NTX, DAT1 10-repeat-allele (10R) homozygotes had less activation than 9-repeat-allele (9R) carriers. Further, 10R homozygotes who received NTX had less mPFC activation than 9R carriers. Polymorphic variation in OPRM1 and DAT1 should be considered in future studies of NTX, particularly regarding its effects on reward processing.

ARIPIPRAZOLE EFFECTS ON ALCOHOL CONSUMPTION AND SUBJECTIVE REPORTS IN A CLINICAL LABORATORY PARADIGM: POSSIBLE INFLUENCE OF SELF-CONTROL

INTRODUCTION There has been increasing interest in the use of medications that affect the dopamine receptor in the treatment of alcoholism. Aripiprazole has the unique pharmacology of being a partial dopamine agonist serving to stabilize brain dopamine systems in both frontal cortical and subcortical areas. As such, it might act to dampen alcohol reinforcement and craving and/or alter control over alcohol use. The current clinical laboratory study was conducted to evaluate the safety and efficacy of aripiprazole as a potential agent to alter drinking and objective effects of alcohol. METHODS Thirty nontreatment seeking alcoholics were enrolled in a subacute human laboratory study and received double-blind treatment with up to 15 mg of aripiprazole (n = 15) or identical placebo (n = 15) for 8 days. Tolerability and utility of aripiprazole was monitored during natural drinking over the first 6 days of medication treatment and also during a free choice limited access alcohol consumption paradigm following an initial drink of alcohol in a bar-lab setting on Day 8. RESULTS Aripiprazole was well tolerated and reduced drinking in nontreatment seeking alcoholics over 6 days of natural drinking--especially in those with lower self control (more impulsive). It also reduced drinks in the bar-lab after a priming drink and broke the link between priming drink induced stimulation and further drinking. During the bar-lab drinking session, there were no differences in subjective high, intoxication, or craving between subjects treated with aripiprazole or placebo. DISCUSSION This study joins several others in demonstrating the utility of subacute dosing laboratory paradigms for evaluating medication effects in alcoholics. Aripiprazole was well tolerated and lowered alcohol use, especially in those with lower impulse control. Further study is needed to determine the safety and utility of aripiprazole in the treatment of alcoholism and if subgroups of alcoholics are more likely to respond.

Predictors of Naltrexone Response in a Randomized Trial: Reward-Related Brain Activation, OPRM1 Genotype, and Smoking Status

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. One hundred and fifty-two treatment-seeking individuals with alcohol dependence, half preselected to carry at least one A118G G (Asp) allele, were randomized to naltrexone (50 mg) or placebo for 16 weeks and administered an fMRI alcohol cue reactivity task at baseline and after 2 weeks of treatment. Naltrexone, relative to placebo, significantly reduced alcohol cue-elicited activation of the right ventral striatum (VS) between baseline and week 2 and reduced heavy drinking over 16 weeks. OPRM1 genotype did not significantly moderate these effects, but G-allele carriers who received naltrexone had an accelerated return to heavy drinking after medication was stopped. Smoking moderated the effects of medication on drinking, such that naltrexone was superior to placebo only among smokers. The degree of reduction in right VS activation between scans interacted with medication in predicting subsequent drinking, such that individuals with greater reduction in activation who received naltrexone, but not placebo, experienced the least heavy drinking during the following 14 weeks. These data replicate previous findings that naltrexone reduces heavy drinking and reward-related brain activation among treatment-seeking individuals with AUDs, and indicate that smoking and the magnitude of reduction in cue-elicited brain activation may predict treatment response.

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

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. The interacting effects of APZ and a variable number tandem repeat (VNTR) polymorphism in DAT1/SLC6A3 (the gene encoding the DA transporter (DAT)) were tested. In addition, interactions between APZ and a genetic composite comprising the DAT1 VNTR and functional polymorphisms in catechol-O-methyltransferase (COMT), DRD2, and DRD4 were evaluated. Ninety-four non-treatment-seeking individuals with AUD were genotyped for these polymorphisms, randomized to APZ (titrated to 15 mg) or placebo for 8 days, and underwent an fMRI alcohol cue-reactivity task (day 7; n=81) and a bar lab paradigm (day 8). Primary outcomes were alcohol cue-elicited ventral striatal (VS) activation and the number of drinks consumed in the bar lab. DAT1 genotype significantly moderated medication effects, such that APZ, relative to placebo, reduced VS activation and bar-lab drinking only among carriers of the DAT1 9-repeat allele, previously associated with lower DAT expression and greater reward-related brain activation. The genetic composite further moderated medication effects, such that APZ reduced the primary outcomes more among individuals who carried a larger number of DAT1, COMT, DRD2, and DRD4 alleles associated with higher DA tone. Taken together, these data suggest that APZ may be a promising AUD treatment for individuals with a genetic predisposition to higher synaptic DA tone.