We hypothesized that (i) higher levels of alcohol consumption would be associated with lower peripheral levels of plasma OT; (ii) regular alcohol use would be associated with OXTR polymorphisms previously linked to problematic alcohol use (e.g., A‐allele carriers of the OXTR rs53576); and (iii) greater alcohol use would be associated with epigenetic modification of OT function (i.e., greater DNA methylation of OXTR promoter regions). This evidence concerns the gene OXTR and alcohol dependence.