Alcohol use disorders (AUDs), including alcohol abuse and dependence, are prevalent and associated with a variety of medical and social problems. Family, twin, and adoption studies have shown that heritable factors play a critical role in determining an individual’s vulnerability to AUDs1,2; twin studies indicate that the heritability of AUDs is around 50–60%.3,4 The incomplete phenotypic concordance between monozygotic twins suggests that environmental and/or epigenetic factors are also important contributors to susceptibility to AUDs.
