Effects of Ghrelin on Alcohol Cue Reactivity and Craving

Only a few medications are approved for the treatment of alcohol dependence and there exists a substantial need for discovering ways to provide more effective treatments. Accordingly, identifying new potential neuropharmacological targets in the treatment of alcohol dependence represents a high priority in public health. Ghrelin is a 28-amino acid peptide acting as the endogenous ligand for the growth hormone secretagogue receptor (GHS-R). Ghrelin was first isolated from the stomach, but a central hypothalamic production of ghrelin has also been demonstrated. Ghrelin plays a key role in the regulation of appetite. Consistent with the common neurobiological substrates for control of food and alcohol consumption, preclinical investigations suggest that ghrelin plays a role in the neurobiology of alcohol dependence, thus representing a new potential neuropharmacology target. In keeping with the preclinical studies, human investigations showed that alcohol consumption affects blood ghrelin levels and that blood ghrelin levels significantly and positively correlate with craving measurements in alcohol-dependent individuals. The effects of exogenous ghrelin injected intravenous (i.v.) in alcohol-dependent individuals, however, have never been investigated. The current project proposes a randomized double-blind placebo-controlled 3-group between-subject laboratory study aimed at investigating the effects of exogenous ghrelin i.v. on non-treatment seeking alcohol-dependent subjects in terms of urges to drink, attention to cues and related psychophysiological measures. This project has the goals to: i) conduct an alcohol laboratory study testing the role of ghrelin i.v., therefore demonstrating the feasibility of such a study and the safety of ghrelin i.v. when administered to alcohol-dependent individuals; and ii) explore the effects of ghrelin i.v. on alcohol craving assessed under controlled conditions, such as a cue-reactivity (CR) experiment. This study will address wh