Raymond F. Anton

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.

An Evaluation of μ-Opioid Receptor (OPRM1) as a Predictor of Naltrexone Response in the Treatment of Alcohol Dependence: Results From the Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) Study

CONTEXT Naltrexone hydrochloride treatment for alcohol dependence works for some individuals but not for everyone. Asn40Asp, a functional polymorphism of the mu-opioid receptor gene (OPRM1), might predict naltrexone response. OBJECTIVE To evaluate whether individuals with alcoholism who are heterozygous (Asp40/Asn40) or homozygous (Asp40/Asp40) for the OPRM1 Asp40 allele respond better to naltrexone. DESIGN Pharmacogenetic analysis conducted between January 1, 2001, and January 31, 2004. SETTING Eleven academic sites in the COMBINE Study. PARTICIPANTS Recently abstinent volunteers who met all 3 of the following conditions: (1) DSM-IV criteria for primary alcohol dependence; (2) participation in the COMBINE Study; and (3) availability of DNA. INTERVENTIONS Alcoholic subjects were treated for 16 weeks with 100 mg of naltrexone hydrochloride (234 Asn40 homozygotes and 67 with at least 1 copy of the Asp40 allele) or placebo (235 Asn40 homozygotes and 68 with at least 1 copy of the Asp40 allele). All participants received medical management (MM) alone or with combined behavioral intervention (CBI). MAIN OUTCOME MEASURES Time trends in percentage of days abstinent, percentage of heavy drinking days, and rates of good clinical outcome. RESULTS Alcoholic subjects with an Asp40 allele receiving MM alone (no CBI) had an increased percentage of days abstinent (P = .07) and a decreased percentage of heavy drinking days (P = .04) if treated with naltrexone vs placebo, while those with the Asn40/Asn40 genotype showed no medication differences. If treated with MM alone and naltrexone, 87.1% of Asp40 carriers had a good clinical outcome, compared with only 54.8% of individuals with the Asn40/Asn40 genotype (odds ratio, 5.75; confidence interval, 1.88-17.54), while, if treated with placebo, 48.6% of Asp40 carriers and 54.0% of individuals with the Asn40/Asn40 genotype had a good clinical outcome (interaction between medication and genotype, P = .005). No gene x medication interactions were observed in those treated with both MM and CBI. CONCLUSIONS These results confirm and extend the observation that the functionally significant OPRM1 Asp40 allele predicts naltrexone treatment response in alcoholic individuals. This relationship might be obscured, however, by other efficacious treatments. OPRM1 genotyping in alcoholic individuals might be useful to assist in selecting treatment options. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00006206.

Behavior and physiology of social stress and depression in female cynomolgus monkeys

The hypothesis that social subordination is stressful, and results in a depressive response in some individuals, was examined in socially housed female cynomolgus monkeys. Social status was manipulated such that half of the previously subordinate females became dominant and half of the previously dominant females became subordinate. Current subordinates hypersecreted cortisol, were insensitive to negative feedback, and had suppressed reproductive function. Current subordinates received more aggression, engaged in less affiliation, and spent more time alone than dominants. Furthermore, they spent more time fearfully scanning the social environment and displayed more behavioral depression than dominants. Current subordinates with a history of social subordination were preferentially susceptible to a behavioral depression response. The results of this experiment suggest that the stress of social subordination causes hypothalamic-pituitary-adrenal and ovarian dysfunction, and support the hypothesis that chronic, low-intensity social stress may result in depression in susceptible individuals.

Interaction of FKBP5 with childhood adversity on risk for post-traumatic stress disorder.

FKBP5 regulates the cortisol-binding affinity and nuclear translocation of the glucocorticoid receptor. Polymorphisms at the FKBP5 locus have been associated with increased recurrence risk of depressive episodes and rapid response to antidepressant treatment. A recent study showed that FKBP5 genotypes moderated the risk of post-traumatic stress disorder (PTSD) symptoms associated with childhood maltreatment. One thousand one hundred forty-three European Americans (EAs) and 1284 African Americans (AAs) recruited for studies of the genetics of substance dependence were also screened for lifetime PTSD. Four single-nucleotide polymorphisms (SNPs) in FKBP5, rs3800373, rs9296158, rs1360780, and rs9470080, were genotyped on the complete sample. Logistic regression analyses were performed to explore the interactive effect of FKBP5 polymorphisms and childhood adversity on the risk for PTSD. After correction for multiple testing, childhood adversity significantly increased the risk for PTSD. FKBP5 genotypes were not associated with the development of the disorder. In AAs, one of the SNPs, rs9470080, moderated the risk of PTSD that was associated with childhood abuse. Without childhood adverse experiences, participants with the TT genotype of this SNP had the lowest risk for PTSD, whereas they had the highest risk for PTSD after childhood adversity exposure. In addition, in EAs, alcohol dependence was observed to interact with childhood adverse experiences, and also FKBP5 polymorphisms, to increase the risk for PTSD. This study provides further evidence of a gene × environment effect of FKBP5 and childhood abuse on the risk for PTSD in AAs. Further study is required in other populations.

Functional neuroimaging studies of alcohol cue reactivity: a quantitative meta-analysis and systematic review.

A comprehensive understanding of the neurobiology of alcohol cue reactivity is critical in identifying the neuropathology of alcohol use disorders (AUD) and developing treatments that may attenuate alcohol craving and reduce relapse risk. Functional neuroimaging studies have identified many brain areas in which alcohol cues elicit activation. However, extant studies have included relatively small numbers of cases, with AUD of varying severity, and have employed many different cue paradigms. We used activation likelihood estimation, a quantitative, coordinate‐based meta‐analytic method, to analyze the brain areas activated by alcohol‐related cues across studies, and to examine whether these areas were differentially activated between cases and controls. Secondarily, we reviewed correlations between behavioral measures and cue‐elicited activation, as well as treatment effects on such activation. Data analyzed were from 28 studies of 679 cases and 174 controls. Among cases, alcohol cues elicited robust activation of limbic and prefrontal regions, including ventral striatum, anterior cingulate and ventromedial prefrontal cortex. As compared to controls, cases demonstrated greater activation of parietal and temporal regions, including posterior cingulate, precuneus and superior temporal gyrus. Cue‐elicited activation of ventral striatum was most frequently correlated with behavioral measures and most frequently reduced by treatment, but these results were often derived from region‐of‐interest analyses that interrogated only limbic regions. These findings support long‐standing theories of mesolimbic involvement in alcohol cue processing, but suggest that cue‐elicited activation of other brain areas may more clearly differentiate cases from controls. Prevention and treatment for AUD should consider interventions that may reduce cue‐elicited activation of these areas.

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.

Genome-wide association study of alcohol dependence: significant findings in African- and European-Americans including novel risk loci

We report a GWAS of alcohol dependence (AD) in European-American (EA) and African-American (AA) populations, with replication in independent samples of EAs, AAs and Germans. Our sample for discovery and replication was 16 087 subjects, the largest sample for AD GWAS to date. Numerous genome-wide significant (GWS) associations were identified, many novel. Most associations were population specific, but in several cases were GWS in EAs and AAs for different SNPs at the same locus,showing biological convergence across populations. We confirmed well-known risk loci mapped to alcohol-metabolizing enzyme genes, notably ADH1B (EAs: Arg48His, P=1.17 × 10−31; AAs: Arg369Cys, P=6.33 × 10−17) and ADH1C in AAs (Thr151Thr, P=4.94 × 10−10), and identified novel risk loci mapping to the ADH gene cluster on chromosome 4 and extending centromerically beyond it to include GWS associations at LOC100507053 in AAs (P=2.63 × 10−11), PDLIM5 in EAs (P=2.01 × 10−8), and METAP in AAs (P=3.35 × 10−8). We also identified a novel GWS association (1.17 × 10−10) mapped to chromosome 2 at rs1437396, between MTIF2 and CCDC88A, across all of the EA and AA cohorts, with supportive gene expression evidence, and population-specific GWS for markers on chromosomes 5, 9 and 19. Several of the novel associations implicate direct involvement of, or interaction with, genes previously identified as schizophrenia risk loci. Confirmation of known AD risk loci supports the overall validity of the study; the novel loci are worthy of genetic and biological follow-up. The findings support a convergence of risk genes (but not necessarily risk alleles) between populations, and, to a lesser extent, between psychiatric traits.

Toward standardization of carbohydrate-deficient transferrin (CDT) measurements: I. Analyte definition and proposal of a candidate reference method.

Abstract An alcohol-associated change in the serum transferrin glycoform pattern, carbohydrate-deficient transferrin (CDT), is used as a biomarker of chronic moderate to heavy alcohol consumption. A current limitation in CDT analysis is the lack of standardization, which hampers clinical and analytical comparison between studies. This situation prompted initiation of a Working Group (WG) on CDT Standardization under the auspices of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). The standardization work aims to define and validate the analyte, select a reference method, work out procedures for the production of reference materials, and make suggestions for the clinical usage of CDT. The first recommendation of the WG is that disialotransferrin should be the primary target molecule for CDT measurement and the single analyte on which CDT standardization is based. It is further recommended that HPLC should be the analytical principle considered as the basis of an interim reference method until a suitable mass spectrometric reference method is established. In clinical use, CDT should be expressed in a relative amount (% CDT), to compensate for variations in the total transferrin concentration. Clin Chem Lab Med 2007;45:558–62.

Adverse childhood events as risk factors for substance dependence: Partial mediation by mood and anxiety disorders

AIMS Adverse childhood events (ACEs) are associated with negative health outcomes. We examined ACEs as risk factors for substance dependence (SD) and the mediating effects of mood and anxiety disorders on the relations between ACEs and SD risk. DESIGN We compared early life experiences in 2061 individuals with a lifetime diagnosis of alcohol, cocaine, or opioid dependence and 449 controls. MEASUREMENTS Diagnostic and ACE data were obtained using the Semi-Structured Assessment for Drug Dependence and Alcoholism. FINDINGS Childhood abuse or exposure to violent crime was positively related to the number of lifetime mood and anxiety disorders and to SD risk. Mood and anxiety disorders had their first onset a mean of nearly 3 years before the first SD diagnosis and partially mediated the effect of ACEs on SD risk. CONCLUSION ACEs appear to contribute additively to the risk of SD, with mood and anxiety disorders in the causal path for a portion of this risk. The identification and effective treatment of mood and anxiety disorders associated with ACEs could reduce the risk of developing SD.

A multi-site dose ranging study of nalmefene in the treatment of alcohol dependence

Abstract: The opiate antagonist nalmefene has been shown in 2 single-site studies to reduce alcohol consumption and relapse drinking in alcohol-dependent individuals. This safety and preliminary multisite efficacy study evaluated 3 doses of nalmefene (5, 20, or 40 mg) in a double-blind comparison to placebo over a 12-week treatment period in 270 recently abstinent outpatient alcohol-dependent individuals. Participants concomitantly received 4 sessions of a motivational enhancement therapy (with a medication compliance component) delivered from trained counselors. Although more subjects in the active medication groups terminated the study early secondary to adverse events, the rates did not differ significantly from that of placebo. The 20-mg/d group experienced more insomnia, dizziness, and confusion, while the 5-mg group also had more dizziness and the 40-mg group had more nausea than the placebo group. Most of these symptoms were mild and improved over time. Although all subjects had a reduction in heavy drinking days, craving, γ-glutamyl transferase, and carbohydrate-deficient transferrin concentrations over the course of the study, there was no difference between the active medication and placebo groups on these measures. The time to first heavy drinking day was also not significantly different between the placebo and the active treatment groups. This relatively small multisite trial showed that nalmefene was reasonably well tolerated in recently abstinent alcoholics. However, possibly because of variation among the sites or the comparatively small sample size, there was no evidence of superior efficacy outcomes with nalmefene treatment.