The impact of the appetite-regulating, orexigenic peptide ghrelin on alcohol use disorders: A systematic review of preclinical and clinical data

Ghrelin, which is mainly released from the stomach, is the most important orexigenic regulator of food intake, inducing appetite, enhancing adiposity and releasing growth hormone. Besides the hypothalamus, ghrelin receptors (GHS-R1A) are also expressed in the mesolimbic dopaminergic system, which increases the possibility that ghrelin plays an important role in reward regulation for substance use disorders such as alcohol addiction, especially through activating the cholinergic-dopaminergic reward link. In this review we focus on the impact of ghrelin on the development and maintenance of alcohol addiction/dependence, alcohol consumption, alcohol craving and alcohol withdrawal, attempting to integrate preclinical and clinical studies concerning the intriguing relationship between appetite regulation, reward and alcohol addiction. Integrating the existing preclinical and clinical data on ghrelin antagonism, specifically at the GHS-R1A receptor in mesolimbic dopaminergic pathways, may reveal a new and innovative target for the treatment of alcohol dependence in the future.