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Rao R, Topiwala A. Alcohol use disorders and the brain. Addiction 2020; 115:1580-1589. [PMID: 32112474 DOI: 10.1111/add.15023] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/11/2020] [Accepted: 02/25/2020] [Indexed: 12/15/2022]
Abstract
A diagnosis of alcohol use disorder is associated with a higher risk of dementia, but a dose-response relationship between alcohol intake consumption and cognitive impairment remains unclear. Alcohol is associated with a range of effects on the central nervous system at different doses and acts on a number of receptors. Acute disorders include Wernicke's encephalopathy (WE), traumatic brain injury, blackouts, seizures, stroke and hepatic encephalopathy. The most common manifestations of chronic alcohol consumption are Korsakoff's syndrome (KS) and alcohol-related dementia (ARD). There is limited evidence for benefit from memantine in the treatment of ARD, but stronger evidence for the use of high-dose parenteral thiamine in the progression of neuropsychiatric symptoms for WE. Accumulating evidence exists for pharmacological treatment in the prevention of hepatic encephalopathy. Rehabilitation of people with ARD may take several years, and requires an approach that addresses physical and psychosocial factors.
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Affiliation(s)
- Rahul Rao
- Institute of Psychiatry, Psychology and Neuroscience, Department of Old Age Psychiatry, London, UK.,South London and Maudsley NHS Foundation Trust, Psychological Medicine and Older Adults Directorate, London, UK
| | - Anya Topiwala
- University of Oxford, Big Data Institute, Nuffield Department of Population Health
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2
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Ray LA, Green R, Roche DJ, Magill M, Bujarski S. Naltrexone effects on subjective responses to alcohol in the human laboratory: A systematic review and meta-analysis. Addict Biol 2019; 24:1138-1152. [PMID: 31148304 DOI: 10.1111/adb.12747] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 02/13/2019] [Accepted: 02/24/2019] [Indexed: 02/03/2023]
Abstract
Naltrexone (NTX) has been widely studied for the treatment of alcohol use disorder with overall support for its efficacy. The mechanisms of action of naltrexone are thought to involve attenuation of the hedonic effects of alcohol and potentiation of its aversive effects. In order to provide a quantitative estimate of the effects of naltrexone on subjective response to alcohol, the aims of this meta-analytic review are to examine the effects of naltrexone across four domains of subjective response. Meta-analyses of naltrexone effects on alcohol craving (k = 16, N = 686), stimulation (k = 15, N = 675), sedation (k = 18, N = 777), and negative mood (k = 9, N = 281) suggested that under laboratory conditions and compared with placebo, naltrexone reduces craving (Hedges g = -0.252; SE = 0.054; 95% CI, -0.375 to -0.130; P < 0.01), reduces stimulation (g = -0.223; SE = 0.067; 95% CI, -0.372 to -0.074; P < 0.01), increases sedation (g = 0.251; SE = 0.064; 95% CI, 0.112-0.389; P < 0.01), and increases negative mood (g = 0.227; SE = 0.047; 95% CI, 0.100-0.354; P < 0.01). Results were robust when drinks per month and alcohol dose were added to the models as covariates. The effects of naltrexone varied by severity of alcohol use with medication effects on craving and stimulation being observed in sample of both heavy drinkers and AUD individuals. These results are consistent with the hypothesized mechanisms of action of NTX, although the effects are of small magnitude. This meta-analysis aggregates across multiple human laboratory studies of NTX's effects on subjective response to alcohol, providing a comprehensive summary of a key mechanism of NTX efficacy, namely, alteration of the subjective experience of alcohol.
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Affiliation(s)
- Lara A. Ray
- Department of PsychologyUniversity of California, Los Angeles Los Angeles CA USA
- Department of Psychiatry and Biobehavioral SciencesUniversity of California, Los Angeles Los Angeles CA USA
| | - ReJoyce Green
- Department of PsychologyUniversity of California, Los Angeles Los Angeles CA USA
| | | | - Molly Magill
- Center for Alcohol and Addiction StudiesBrown University Providence RI USA
| | - Spencer Bujarski
- Department of PsychologyUniversity of California, Los Angeles Los Angeles CA USA
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Hendershot CS, Wardell JD, Samokhvalov AV, Rehm J. Effects of naltrexone on alcohol self-administration and craving: meta-analysis of human laboratory studies. Addict Biol 2017; 22:1515-1527. [PMID: 27411969 PMCID: PMC6139429 DOI: 10.1111/adb.12425] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 05/19/2016] [Accepted: 06/21/2016] [Indexed: 12/21/2022]
Abstract
Randomized clinical trials have established the efficacy of naltrexone for reducing quantity of alcohol consumption and incidence of relapse to heavy drinking. To evaluate putative treatment mechanisms, human laboratory studies have examined naltrexone's effects on alcohol responses and self-administration during short-term medication protocols. Results from these studies are inconsistent and have yet to be examined in aggregate. This meta-analysis aimed to quantify naltrexone's effects on alcohol self-administration and craving in the context of placebo-controlled human laboratory trials. Potential moderators of medication effects were also examined. Meta-analyses of alcohol self-administration (k = 9, N = 490) and craving (k = 16, N = 748) confirmed that, under controlled experimental conditions, naltrexone reduces the quantity of consumption (Hedges' g = -.277, SE = .074, 95 percent CI = -.421, -.133, p < .001) and magnitude of self-reported craving (g = -.286, SE = .066, 95 percent CI = -.416, -.156, p < .001) relative to placebo. Subgroup and moderation analyses found no evidence that effect sizes differed by study population (dependent versus non-dependent drinkers), laboratory paradigm or duration of medication exposure. These results substantiate prior evidence for reductions in event-level craving and consumption as potential treatment mediators, also establishing effect sizes to inform future human laboratory trials. From a clinical perspective, these results may provide additional evidence regarding naltrexone's efficacy in the context of acute or subacute dosing regimens.
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Affiliation(s)
- Christian S. Hendershot
- Campbell Family Mental Health Research InstituteCentre for Addiction and Mental HealthCanada
- Department of Psychiatry, University of TorontoCanada
- Department of PsychologyUniversity of TorontoCanada
- Institute for Mental Health Policy ResearchCentre for Addiction and Mental HealthCanada
| | - Jeffrey D. Wardell
- Campbell Family Mental Health Research InstituteCentre for Addiction and Mental HealthCanada
| | - Andriy V. Samokhvalov
- Department of Psychiatry, University of TorontoCanada
- Institute for Mental Health Policy ResearchCentre for Addiction and Mental HealthCanada
- Institute for Medical SciencesUniversity of TorontoCanada
| | - Jürgen Rehm
- Campbell Family Mental Health Research InstituteCentre for Addiction and Mental HealthCanada
- Department of Psychiatry, University of TorontoCanada
- Institute for Mental Health Policy ResearchCentre for Addiction and Mental HealthCanada
- Dalla Lana School of Public HealthUniversity of TorontoCanada
- Technische UniversitätGermany
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Abstract
Conventional wisdom and survey data indicate that alcohol is a social lubricant and is consumed for its social effects. In contrast, the experimental literature examining alcohol's effects within a social context reveals that alcohol does not consistently enhance social-emotional experience. We identify a methodological factor that might explain inconsistent alcohol-administration findings, distinguishing between studies featuring unscripted interactions among naïve participants (k = 18) and those featuring scripted social interactions with individuals identified as study confederates (k = 18). While 89% of naïve-participant studies find positive effects of alcohol on mood (d = 0.5), only 11% of confederate studies find evidence of significant alcohol-related mood enhancement (d = -0.01). The naïve-participant versus confederate distinction remains robust after controlling for various moderators including stress manipulations, gender, group size, anxiety outcome measure, and within-group consistency of beverage assignment. Based on the findings of our review, we propose a multidimensional, social-attributional framework for understanding alcohol-related reward. Borrowing organizing principles from attribution theory, the social-attributional approach predicts that alcohol will enhance mood when negative outcomes are perceived to be unstable and/or self-relevant. Our framework proposes that alcohol's effects within a social context are largely explained by its tendency to free individuals from preoccupation with social rejection, allowing them to access social rewards. The social-attributional approach represents a novel framework for integrating distinct, well-validated concepts derived from several theories of alcohol's effects. It further presents promising lines of inquiry for future research examining the role of social factors in alcohol reward and addiction susceptibility.
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Conrad M, McNamara P, King A. Alternative substance paradigm: effectiveness of beverage blinding and effects on acute alcohol responses. Exp Clin Psychopharmacol 2012; 20:382-9. [PMID: 22867037 PMCID: PMC4048031 DOI: 10.1037/a0029261] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A fundamental goal of double-blind alcohol challenge studies is to reduce alcohol expectancies, though there is little research on the effectiveness of blinding procedures and their relationship to acute alcohol responses. This study examined social drinkers' perception of beverage content and related alcohol response during 3 separate double-blind experimental sessions with placebo, low-dose alcohol (0.4 g/kg), and high-dose alcohol (0.8 g/kg). Using the alternative substance paradigm, participants (N = 182) were informed that the beverage they consumed might contain alcohol, a stimulant, a sedative, or a placebo. At several time points, subjective and objective measures were obtained, and participants were asked to identify which substance they received. During both placebo and low-dose alcohol sessions, 33% and 50% of participants, respectively, did not correctly identify the beverage content; during the high-dose alcohol session, 20% did not correctly identify the beverage. Although correct and incorrect identifiers at any dose level did not differ on major background variables, drinking characteristics, or psychomotor performance during these sessions, they did differ on self-reported subjective responses, with greater sedation reported by incorrect identifiers in the placebo and high-dose conditions. In summary, results suggest that the alternative substance paradigm may be a viable option for alcohol laboratory studies, particularly for repeated sessions in within-subject designs and in cases in which the experimenter wants to reduce expectancy by not revealing a priori that alcohol is being administered.
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Affiliation(s)
- Megan Conrad
- Department of Psychology, University of Illinois at Chicago, 1007 W. Harrison Street, MC 285, Chicago, IL 60607, USA.
| | - Patrick McNamara
- Department of Psychiatry & Behavioral Neuroscience, Pritzker School of Medicine, University of Chicago, Chicago, IL
| | - Andrea King
- Department of Psychiatry & Behavioral Neuroscience, Pritzker School of Medicine, University of Chicago, Chicago, IL
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Stanley MD, Poole MM, Stoops WW, Rush CR. Amphetamine self-administration in light and moderate drinkers. Alcohol Clin Exp Res 2010; 35:443-53. [PMID: 21158875 DOI: 10.1111/j.1530-0277.2010.01361.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Light and moderate drinkers respond differently to the effects of abused drugs, including stimulants such as amphetamine. The purpose of this study was to determine whether light and moderate drinkers differ in their sensitivity to the reinforcing and subjective effects of d-amphetamine. We hypothesized that moderate drinkers (i.e., participants that reported consuming at least seven alcohol-containing beverages per week) would be more sensitive to the reinforcing and positive subject-rated effects of d-amphetamine than light drinkers. METHODS Data from four studies that employed similar d-amphetamine self-administration procedures and subject-rated drug-effect measures were included in the analysis. Light (n = 17) and moderate (n = 16) drinkers sampled placebo, low (8 to 10 mg), and high (16 to 20 mg) doses of oral d-amphetamine administered in eight capsules. Following sampling sessions, participants worked for a maximum of eight capsules, each containing 12.5% of the previously sampled dose, on a modified progressive-ratio schedule of reinforcement. RESULTS Both active doses of d-amphetamine functioned as a reinforcer in the moderate drinkers, while only the high dose did so in the light drinkers. The moderate drinkers worked for significantly more capsules that contained the high dose of d-amphetamine than did the light drinkers. d-Amphetamine produced prototypical stimulant-like subjective effects (e.g., dose-dependent increases in ratings of Good Effects; Like Drug and Willing to Take Again). Moderate drinkers reported significantly greater subjective effects than the light drinkers. CONCLUSION These results are consistent with those from previous laboratory experiments and suggest that moderate alcohol consumption may increase vulnerability to the abuse-related effects of stimulants.
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Affiliation(s)
- Matthew D Stanley
- Department of Behavioral Science, University of Kentucky College of Medicine, Lexington, USA
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Dose-dependent reduction of hazardous alcohol use in a placebo-controlled trial of naltrexone for smoking cessation. Int J Neuropsychopharmacol 2009; 12:589-97. [PMID: 18796184 PMCID: PMC3094855 DOI: 10.1017/s146114570800936x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The opiate antagonist naltrexone (Ntx) has demonstrated efficacy in the treatment of alcohol dependence and as a component of treatment to reduce heavy drinking. At present, there are no published dose-ranging clinical trials of the oral preparation for treatment of problem drinking. The present study evaluated the effects of Ntx on alcohol use among the subset of hazardous drinkers (n=102) who participated in a placebo-controlled, dose-ranging trial of oral Ntx (25-mg, 50-mg and 100-mg doses) combined with open-label transdermal nicotine patch for enhancing smoking cessation. On the primary outcome--no hazardous drinking (drinking that exceeded weekly or daily limits) during treatment--25 mg and 50 mg Ntx were superior to placebo (each p<0.05). These findings remained after controlling for baseline predictors or smoking abstinence during treatment. Time to remission of hazardous drinking was examined as a secondary outcome with definitions of hazardous drinking based on weekly limits, daily limits and the combination of weekly and daily limits and the results were consistent with the primary findings. In conclusion, the findings suggest that Ntx can reduce the risk of hazardous drinking in smokers who are not seeking or receiving alcohol treatment, providing strong evidence for the pharmacological effects of Ntx on drinking. This effect appears to favour lower doses that may be better tolerated and less expensive than the higher 100-mg dose. Given its efficacy and favourable side-effect profile, the 25-mg dose should be considered for future studies of combination therapy.
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Spanagel R. Alcoholism: A Systems Approach From Molecular Physiology to Addictive Behavior. Physiol Rev 2009; 89:649-705. [DOI: 10.1152/physrev.00013.2008] [Citation(s) in RCA: 491] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Alcohol consumption is an integral part of daily life in many societies. The benefits associated with the production, sale, and use of alcoholic beverages come at an enormous cost to these societies. The World Health Organization ranks alcohol as one of the primary causes of the global burden of disease in industrialized countries. Alcohol-related diseases, especially alcoholism, are the result of cumulative responses to alcohol exposure, the genetic make-up of an individual, and the environmental perturbations over time. This complex gene × environment interaction, which has to be seen in a life-span perspective, leads to a large heterogeneity among alcohol-dependent patients, in terms of both the symptom dimensions and the severity of this disorder. Therefore, a reductionistic approach is not very practical if a better understanding of the pathological processes leading to an addictive behavior is to be achieved. Instead, a systems-oriented perspective in which the interactions and dynamics of all endogenous and environmental factors involved are centrally integrated, will lead to further progress in alcohol research. This review adheres to a systems biology perspective such that the interaction of alcohol with primary and secondary targets within the brain is described in relation to the behavioral consequences. As a result of the interaction of alcohol with these targets, alterations in gene expression and synaptic plasticity take place that lead to long-lasting alteration in neuronal network activity. As a subsequent consequence, alcohol-seeking responses ensue that can finally lead via complex environmental interactions to an addictive behavior.
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Zacny JP, Walker DJ, Drum M, Sells M. Choice of sevoflurane and its subjective and psychomotor effects in light and moderate drinkers. Drug Alcohol Depend 2008; 94:101-8. [PMID: 18077105 PMCID: PMC2288701 DOI: 10.1016/j.drugalcdep.2007.10.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 10/18/2007] [Accepted: 10/18/2007] [Indexed: 11/30/2022]
Abstract
BACKGROUND Sevoflurane, an inhalant of the volatile anesthetic class, has neurobiological and behavioral effects in common with abused inhalants and ethanol. We sought to determine if choice for subanesthetic doses of sevoflurane, and its subjective and psychomotor effects, would differ as a function of alcohol-drinking status in healthy volunteers. METHODS The effects of four concentrations of sevoflurane (0, 0.2, 0.4, 0.8% sevoflurane in oxygen) were studied in 16 light drinkers and 16 moderate drinkers. During each of four sessions, subjects sampled a concentration of sevoflurane and 100% O(2) (placebo) for 10 min each. Subjective and psychomotor testing commenced 5 min into each sampling trial. Later, within the session, subjects chose nine times, once every 5 min, among sevoflurane (e.g., "Agent A"), placebo (e.g., "Agent B," 100% O(2)), or neither (and were administered 100% O(2), identified as "drug-free air"). RESULTS Choice for sevoflurane at the 0.4% concentration was significantly higher in the moderate drinkers than in the light drinkers. A number of subjective effects reported during inhalation of sevoflurane were markedly lower in the moderate-drinking group than in the light-drinking group. However, psychomotor impairment induced by sevoflurane was similar in magnitude in both groups. CONCLUSIONS Alcohol-drinking status affected sevoflurane choice. The results are consistent with several studies comparing light and heavier drinkers, using other drugs. Although both drinking groups were similarly impaired by sevoflurane, the moderate drinkers reported less of a subjective response than light drinkers, suggestive of cross-tolerance.
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Affiliation(s)
- James P. Zacny
- Department of Anesthesia and Critical Care The University of Chicago Chicago. Illinois USA
| | - Diana J. Walker
- Department of Anesthesia and Critical Care The University of Chicago Chicago. Illinois USA
| | - Melinda Drum
- Department of Health Studies The University of Chicago Chicago. Illinois USA
| | - Molly Sells
- Department of Anesthesia and Critical Care The University of Chicago Chicago. Illinois USA
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Brumback T, Cao D, King A. Effects of alcohol on psychomotor performance and perceived impairment in heavy binge social drinkers. Drug Alcohol Depend 2007; 91:10-7. [PMID: 17560739 PMCID: PMC2764986 DOI: 10.1016/j.drugalcdep.2007.04.013] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2006] [Revised: 04/13/2007] [Accepted: 04/26/2007] [Indexed: 11/30/2022]
Abstract
Alcohol intoxication often results in negative consequences; however, specific behavioral and subjective effects vary as a function of individual differences. The present study utilized an alcohol challenge paradigm to examine whether heavy binge social drinkers (HD; n=77), compared to light social drinkers (LD; n=55), exhibit: (1) greater tolerance in psychomotor task performance under the influence of alcohol, and (2) differential perceptions of the impairing effects of alcohol. The study included three test sessions in which participants consumed either a low (0.4 g/kg) or a high (0.8 g/kg) dose of ethanol or a placebo beverage administered in random order and counterbalanced within group. Participants completed the Digit-Symbol Substitution Task (DSST) and the Grooved Pegboard at pre-drink baseline and at multiple time points after beverage consumption. They also completed a scale of perceived impairment at several intervals after beverage consumption. Ethanol impaired performance at the high dose, but not at the low dose (ps<.001). The groups exhibited similar alcohol-induced impairment. However, HD reported lower self-perceived impairment compared to LD, particularly during the early portion of the blood alcohol curve when actual impairment was most pronounced (p<.001). Thus, this study extends prior research in that habitual binge social drinking does not appear to be associated with tolerance to alcohol's impairing effects on select psychomotor skills. Further, results may have implications for alcohol-related harm as binge social drinkers regularly consume intoxicating doses of alcohol but may not be aware of the physical and cognitive impairments produced by alcohol.
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Affiliation(s)
- Ty Brumback
- The University of Chicago, Department of Psychiatry, Chicago, IL 60637, USA.
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Smith SS, Gong QH. Ethanol effects on GABA-gated current in a model of increased alpha4betadelta GABAA receptor expression depend on time course and preexposure to low concentrations of the drug. Alcohol 2007; 41:223-31. [PMID: 17591545 PMCID: PMC2658629 DOI: 10.1016/j.alcohol.2007.04.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 04/17/2007] [Accepted: 04/17/2007] [Indexed: 01/28/2023]
Abstract
Several recent studies have suggested that alphabetadelta subtypes of gamma-aminobutyric acid type A (GABAA) receptors (delta-GABAR) are a target for low dose ethanol (<30 mM). However, there are also conflicting reports suggesting that only high doses of the drug (100 mM) modulate these receptors. In addition, the studies which have demonstrated a clear effect of low dose ethanol on delta-GABAR find different effective concentrations for this effect. Here, we test the hypothesis that the apparent disparity in effective concentration is due to time-course effects when low (1-3 mM) dose ethanol is preapplied. To this end, we tested ethanol effects on native GABAR in CA1 hippocampus in a model of increased alpha4betadelta GABAR expression following 48h administration of the GABA-modulatory steroid THP (3alpha-OH-5beta-pregnan-20-one) to adult, female rats. GABA(EC20)-gated current was recorded with whole-cell patch clamp procedures from acutely isolated pyramidal cells. We assessed ethanol's effect on GABA-gated current using either (1) 2-5 min application of ethanol in increasing concentrations (0.1-30 mM) or (2) coadministration of ethanol with GABA. Two minute application of 1-3 mM ethanol produced optimal potentiation of GABA-gated current following steroid treatment, with higher concentrations less effective. In contrast, 30 mM ethanol produced optimal effects when ethanol was not preapplied. However, following preapplication of 1mM ethanol, 30 mM ethanol decreased the peak GABA-gated current. These findings suggest that ethanol may act at multiple interacting sites to affect GABAR efficacy and desensitization. These data also suggest that ethanol effects on GABA-gated current are affected by the time course of exposure and previous exposure to low concentrations of the drug.
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Affiliation(s)
- Sheryl S Smith
- Department of Physiology and Pharmacology, Box 31, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
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12
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Jayaram-Lindström N, Wennberg P, Hurd YL, Franck J. Effects of naltrexone on the subjective response to amphetamine in healthy volunteers. J Clin Psychopharmacol 2004; 24:665-9. [PMID: 15538132 DOI: 10.1097/01.jcp.0000144893.29987.e5] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
While dopaminergic mechanisms in amphetamine-taking behavior have been extensively studied, the contribution of the endogenous opioid system is less clear. We assessed the effects of an opioid antagonist, naltrexone (50 mg), on the subjective response to an oral dose of dexamphetamine (30 mg) in 12 healthy volunteers in a double-blind, placebo-controlled design. Volunteers received a total of 4 combinations of the study preparation (placebo-naltrexone, placebo-amphetamine) over 4 occasions with 1-week intervals. The primary objective of the study was to evaluate the effect of pretreatment with naltrexone on the subjective response to amphetamine. This was measured using a Visual Analog Scale, assessing the subjective effects over 7 hours. The secondary objective was to measure the effects of naltrexone on behavioral and physiologic responses to amphetamine. This was measured by blood pressure, heart rate, skin conductance, and speed of reading at the end of each session. Amphetamine produced significant effects on subjective arousal when compared to placebo after 1 hour (P < 0.001) and continued to be evident until 7 hours. Pretreatment with naltrexone significantly attenuated the subjective effects of amphetamine (P < 0.05), and this effect was time-dependent with a reduction from the 3-hour time point. Naltrexone did not influence the behavioral and physiologic effects of amphetamine in this sample. The results provide preliminary evidence that naltrexone may reduce the reinforcing effects of amphetamine via modulation of the opioid system. The potential of naltrexone as an adjunct pharmaceutical for the treatment of amphetamine dependence is promising and needs to be investigated further.
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Affiliation(s)
- Nitya Jayaram-Lindström
- Section of Alcohol and Drug Dependence Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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13
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Abstract
Although far from conclusive, evidence implicating the endogenous opioid system in the development and maintenance of alcoholism is growing. Currently available data suggest that ethanol increases opioid neurotransmission and that this activation is part of the mechanism responsible for its reinforcing effects. Findings from preclinical research indicate that ethanol consumption and ethanol-induced dopamine (DA) release are both reduced by opioid antagonists. Individual differences in endogenous opioid activity have been linked to inherited risks for alcoholism in studies comparing ethanol-preferring and nonpreferring rats, as well as in studies using targeted gene mutation (knockout) strategies. To a large extent, findings from human studies have paralleled those from the preclinical work. Persons who differ in family history of alcoholism have been shown to also differ in basal beta-endorphin activity, beta-endorphin response to alcohol, and subjective and HPA axis hormonal response to opioid antagonists. Findings from clinical trials indicate that opioid antagonists may reduce ethanol consumption in alcoholics, particularly in persons who have resumed drinking. Nevertheless, many questions remain unanswered about the use of opioid antagonists in alcoholism treatment and about the exact role of the opioid system in ethanol preference and reward. The progression of knowledge in this field suggests that many of these questions are imminently answerable, as our ability to characterize relationships between opioid activity and human behavior continues to develop. This paper summarizes both the progress that has been made and the gaps that remain in our understanding of the interactions between the endogenous opioid system and risk for alcoholism.
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Affiliation(s)
- L M Oswald
- Departments of Medicine and Psychiatry, The Johns Hopkins University, School of Medicine, Ross Research Building, Room 863, 720 Rutland Avenue, Baltimore, MD 21205, USA
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Kranzler HR, Armeli S, Feinn R, Tennen H. Targeted Naltrexone Treatment Moderates the Relations Between Mood and Drinking Behavior Among Problem Drinkers. J Consult Clin Psychol 2004; 72:317-27. [PMID: 15065964 DOI: 10.1037/0022-006x.72.2.317] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
One hundred fifty-three problem drinkers were randomly assigned to receive naltrexone 50 mg or placebo on a daily or targeted (to high-risk drinking situations) basis. Using structured nightly diaries, participants recorded negative and positive mood, desire to drink, and alcohol consumption over 8 weeks. Results indicated that individuals engaged in any drinking and heavy drinking more on days characterized by relatively higher levels of positive or negative mood states. Naltrexone attenuated the positive association between heavy drinking and both positive and negative mood, and targeted administration attenuated the positive association between heavy drinking and positive mood. There was also evidence that desire to drink mediated the effect of targeted administration on the relation between positive mood and any drinking that day. These findings underscore the utility of daily measurement for understanding the processes that underlie pharmacological interventions for problem drinking.
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Affiliation(s)
- Henry R Kranzler
- Alcohol Research Center, Department of Psychiatry, University of Connecticut School of Medicine, Farmington, CT 06030-2103, USA.
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15
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Stoops WW, Fillmore MT, Poonacha MS, Kingery JE, Rush CR. Alcohol choice and amphetamine effects in light and moderate drinkers. Alcohol Clin Exp Res 2003; 27:804-11. [PMID: 12766625 DOI: 10.1097/01.alc.0000067977.23096.6a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The results of previously published reports suggest that light and moderate drinkers respond differently to the effects of commonly abused sedatives (e.g., diazepam or ethanol). The purpose of this experiment was to determine whether light and moderate drinkers respond differentially to the effects of ethanol and d-amphetamine. METHODS In the first phase of this experiment, volunteers (eight light drinkers and eight moderate drinkers) randomly sampled 0.5 g/kg of ethanol and placebo across two separate sessions. In the second phase, volunteers completed three sessions in which they chose either ethanol or placebo. In the third phase, volunteers received 0, 5, 10, and 15 mg of d-amphetamine. Each dose was tested twice. After drug administration in each phase, volunteers completed a battery of subject-rated, performance, and physiologic measures periodically for 5 hr. RESULTS Ethanol produced prototypical subject-rated effects (e.g., increased ratings on the Alcohol Sensation Scale), but it was chosen over placebo infrequently. Light and moderate drinkers did not differ in terms of the self-reported or reinforcing effects of ethanol. d-Amphetamine produced prototypical subject-rated stimulant-like effects (e.g., dose-dependent increases in ratings of High and Rush). Moderate drinkers reported significantly greater drug effects than light drinkers. Responses to ethanol reliably predicted subsequent responses to d-amphetamine on several measures. CONCLUSIONS The results of this experiment suggest that even moderate ethanol use may increase an individual's vulnerability to abuse drugs. Future studies should determine whether light and moderate drinkers respond differentially to other commonly abused drugs (e.g., opioids) and whether behavioral responses to ethanol also predict responses to these compounds.
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Affiliation(s)
- William W Stoops
- Department of Behavioral Science, College of Medicine, University of Kentucky, Lexington, KY 40536-0086, USA
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16
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Abstract
A variety of evidence suggests that endogenous opioid peptides play a role in the short-term control of eating. More recently, opioid receptor antagonists like naltrexone have been approved as a treatment for alcohol dependence. Here we review the evidence for a role of opioid peptides in both normal and abnormal eating and drinking behaviours and in particular try to identify the nature of the role of opioids in these behaviours. Particular attention is paid to the idea that opioid reward processes may be involved both in the short-term control of eating and hedonic aspects of alcohol consumption, and parallels are drawn between the effects of opiate antagonists on food pleasantness and the experience of drinking alcohol. The review also explores the extent to which data from studies using opiate antagonists and agonists provide evidence for a direct role of endogenous opioids in the control of ingestive behaviour, or alternatively whether these data may be better explained through non-specific effects such as the nausea commonly reported following administration of opiate antagonists. The review concludes that the present data suggests a single opioid mechanism is unlikely to explain all aspects of ingestive behaviour, but also concludes that opioid-mediated reward mechanisms play an important control in hedonic aspects of ingestion. The review also highlights the need for further empirical work in order to elucidate further the role of opioid peptides in human ingestive behaviour.
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Affiliation(s)
- Martin R Yeomans
- Laboratory of Experimental Psychology, University of Sussex, Brighton, Sussex BN1 9QG, UK.
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17
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Na C, Lee YS. Alcohol urge and plasma beta-endorphin change after alcohol challenge with naltrexone pretreatment in social drinkers. Prog Neuropsychopharmacol Biol Psychiatry 2002; 26:663-70. [PMID: 12188097 DOI: 10.1016/s0278-5846(01)00315-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The authors have investigated the effect of naltrexone (NTX) on lowering the urge of alcohol drinking and the action mechanism of NTX. Fifteen healthy male social drinkers voluntarily participated. The experimental method was a double-blind, placebo-controlled cross-over design. To eliminate NTX effect, 1 week washout cross-over interval was taken. Subjects ingested NTX, 50 mg/day, or placebo for 1 week. Then, the alcohol (0.5 ml/kg) challenge test was done in the evening. Blood samples were taken immediately before drinking, at 20 min and at 60 min after alcohol drinking. Plasma beta-endorphin, plasma ACTH and serum cortisol levels were checked. Subjects completed self-report questionnaires such as the visual analog scales of drink urge and the alcohol sensation scales at regular intervals. In the case of NTX pretreatment, the subjects reported significantly (P=.013) less urge to drink alcohol on the self-reporting urge scales, especially at postdrinking 20 min and 60 min than placebo pretreatment. After alcohol challenge, the subjects reported significantly more dizziness (P=.015) in the case of NTX pretreatment, and reported less mood elevation trend, though not significant (P=.052). Basal plasma beta-endorphin levels were not different, but in the case of NTX pretreatment, the increasing degree of plasma beta-endorphin during 20 min after alcohol challenge was significantly (P=.039) higher than with placebo pretreatment. This results show that the NTX reduced the urge to drink alcohol with the mechanism of partially blocking the opioid positive reward system and partially mimicking the alcohol effect.
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Affiliation(s)
- Chul Na
- Department of Neuropsychiatry, College of Medicine, Chung-Ang University Medical Center, Seoul, South Korea.
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18
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Pretreatment With Hydromorphone, a ??-Opioid Agonist, Does Not Alter the Acute Behavioral and Physiological Effects of Ethanol in Humans. Alcohol Clin Exp Res 2001. [DOI: 10.1097/00000374-200101000-00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Rush CR. Pretreatment With Hydromorphone, a mu-Opioid Agonist, Does Not Alter the Acute Behavioral and Physiological Effects of Ethanol in Humans. Alcohol Clin Exp Res 2001. [DOI: 10.1111/j.1530-0277.2001.tb02121.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Richards JB, Zhang L, Mitchell SH, de Wit H. Delay or probability discounting in a model of impulsive behavior: effect of alcohol. J Exp Anal Behav 1999; 71:121-43. [PMID: 10220927 PMCID: PMC1284697 DOI: 10.1901/jeab.1999.71-121] [Citation(s) in RCA: 592] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Little is known about the acute effects of drugs of abuse on impulsivity and self-control. In this study, impulsivity was assessed in humans using a computer task that measured delay and probability discounting. Discounting describes how much the value of a reward (or punisher) is decreased when its occurrence is either delayed or uncertain. Twenty-four healthy adult volunteers ingested a moderate dose of ethanol (0.5 or 0.8 g/kg ethanol: n = 12 at each dose) or placebo before completing the discounting task. In the task the participants were given a series of choices between a small, immediate, certain amount of money and $10 that was either delayed (0, 2, 30, 180, or 365 days) or probabilistic (i.e., certainty of receipt was 1.0, .9, .75, .5, or .25). The point at which each individual was indifferent between the smaller immediate or certain reward and the $10 delayed or probabilistic reward was identified using an adjusting-amount procedure. The results indicated that (a) delay and probability discounting were well described by a hyperbolic function; (b) delay and probability discounting were positively correlated within subjects; (c) delay and probability discounting were moderately correlated with personality measures of impulsivity; and (d) alcohol had no effect on discounting.
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Affiliation(s)
- J B Richards
- Department of Psychiatry, University of Chicago, Illinois 60637, USA
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21
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Abstract
This paper is the twentieth installment of our annual review of research concerning the opiate system. It summarizes papers published during 1997 that studied the behavioral effects of the opiate peptides and antagonists, excluding the purely analgesic effects, although stress-induced analgesia is included. The specific topics covered this year include stress; tolerance and dependence; eating and drinking; alcohol; gastrointestinal, renal, and hepatic function; mental illness and mood; learning, memory, and reward; cardiovascular responses; respiration and thermoregulation; seizures and other neurologic disorders; electrical-related activity; general activity and locomotion; sex, pregnancy, and development; immunologic responses; and other behaviors.
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Affiliation(s)
- G A Olson
- Department of Psychology, University of New Orleans, LA 70148, USA
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