1. Heavy drinking may change DNA, leading to increased craving for alcohol.
2. Omkaram Gangisetty et al, Hypermethylation of Proopiomelanocortin and Period 2 Genes in Blood Are Associated with Greater Subjective and Behavioral Motivation for Alcohol in Humans, Alcoholism: Clinical and Experimental Research (2018). DOI: 10.1111/acer.13932.