MAOA and alcohol abuse: Research has demonstrated that the effects of GLP-1 in alcohol use disorder and SUD are mediated partly through the downregulation of dopamine signaling and even enhanced catabolism in both the synapse and mitochondria due to GLP1 agonistic increase in the gene expression such as Catechol-O-methyltransferase (COMT) and Monoamine Oxidase A (MAOA) [30, 31].