Etiological contributions to heavy drinking from late adolescence to young adulthood

The authors examined genetic and environmental contributions to stability and change in heavy drinking from late adolescence to young adulthood in a sample of 1,152 twin pairs. In men, heavy drinking was similarly heritable at ages 17 (h² = .57) and 20 (h² = .39), and its stability owed primarily to common genetic factors. In women, heavy drinking was less heritable than in men at ages 17 (h² = .18) and 20 (h² = .30) and its stability was primarily due to enduring shared environmental influences. P3 amplitude, an event-related brain potential marker of alcoholism risk, was less predictive of heavy drinking in women than in men, providing further support for the proposition that biological factors have less impact on heavy drinking in young adult women than in young adult men.