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- Gowin, Joshua L., et al.
(författare)
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The Effect of Varenicline on the Neural Processing of Fearful Faces and the Subjective Effects of Alcohol in Heavy Drinkers
- 2016
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Ingår i: Alcoholism. - : WILEY-BLACKWELL. - 0145-6008 .- 1530-0277. ; 40:5, s. 979-987
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Tidskriftsartikel (refereegranskat)abstract
- Background: Pharmacotherapies for alcohol use disorder have been shown to reduce hazardous drinking and improve overall health. The effect sizes for the effectiveness of these medications, however, are small, underscoring the need to expand the range of therapeutics and develop personalized treatment approaches. Recent studies have suggested that varenicline, an 42-nicotinic partial agonist widely used for smoking cessation, can help alcoholics reduce drinking, but the neurocognitive underpinnings of its effectiveness remain largely unexplored. Methods: In this double-blind study, 32 heavy drinkers were randomized to receive varenicline (2 mg/d) or placebo. After 2 weeks of dosing, participants underwent functional MRI scans, during which they viewed images of faces with either neutral or fearful expressions at baseline and following an intravenous alcohol infusion to a target breath alcohol concentration of 80 mg%. Blood oxygen level-dependent (BOLD) response was analyzed with Analysis of Functional Neuroimaging software. Linear mixed-effects models were used to examine the effects of facial expression (fearful vs. neutral) and medication (placebo vs. varenicline) on BOLD response. The effect of medication on measures of subjective response to alcohol was also examined. Results: Results indicated a significant facial expression-by-medication interaction in the left amygdala. The groups showed equivalent activation to neutral faces, but, whereas the placebo group showed increased activation to fearful faces, the varenicline group showed no change in activation. Amygdala activation to fearful faces correlated with number of drinks in the previous 90 days and Obsessive Compulsive Drinking Scale scores. There was no effect of varenicline on subjective response to alcohol. Conclusions: Our results indicate that varenicline may disrupt amygdala response to fearful faces in heavy drinkers. Further, amygdala activation correlated with alcohol consumption, suggesting that the effects of varenicline may be related to aspects of drinking behavior. These results suggest that amygdala response to fearful faces may be developed as a biomarker of the effectiveness of medications being developed for the treatment of alcohol use disorder.
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| 2. |
- Schwandt, Melanie L., et al.
(författare)
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The CRFI Antagonist Verucerfont in Anxious Alcohol-Dependent Women: Translation of Neuroendocrine, But not of Anti-Craving Effects
- 2016
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Ingår i: Neuropsychopharmacology. - : Nature Publishing Group. - 0893-133X .- 1740-634X. ; 41:12, s. 2818-2829
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Tidskriftsartikel (refereegranskat)abstract
- Blockade of corticotropin-releasing factor receptor I (CRFI) suppresses stress-induced alcohol seeking in rodents, but clinical translation remains. Here, we first showed that the CRFI antagonist verucerfont potently blocks hypothalamic-pituitary adrenal (HPA) axis activation in adrenalectomized rats. We then evaluated verucerfont for its ability to block HPA axis activation and reduce stress-induced alcohol craving in alcohol-dependent patients. Anxious, alcohol-dependent women (age 21-65 years, n = 39) were admitted to the NIH Clinical Center and completed withdrawal treatment before enrollment if needed. One-week single-blind placebo was followed by randomized double-blind verucerfont (350 mg per day) or placebo for 3 weeks. Verucerfont effects on the HPA axis were evaluated using the dexamethasone-CRF test Craving was evaluated using two established protocols, one that combines a social stressor with physical alcohol cue exposure, and one that uses guided imagery to present personalized stress, alcohol, or neutral stimuli. An fMRI session examined brain responses to negative affective stimuli and alcohol cues. In contrast to our recent observations with another CRFI antagonist, pexacerfont, verucerfont potently blocked the HPA axis response to the dexamethasone-CRF test, but left alcohol craving unaffected. Right amygdala responses to negative affective stimuli were significantly attenuated by verucerfont, but responses to alcohol-associated stimuli were increased in some brain regions, including left insula. Discontinuation rates were significantly higher in the verucerfont group. Our findings provide the first translational evidence that CRFI antagonists with slow receptor dissociation kinetics may have increased efficacy to dampen HPA axis responses. The findings do not support a clinical efficacy of CRFI blockade in stress-induced alcohol craving and relapse.
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