Gender differences exist in the prevalence, characteristics, and course of alcohol dependence (AD). Polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) are strong genetic determinants of AD. While inactive ALDH2 traditionally delays the development of AD in men, a new study has found that inactive ALDH2 can accelerate the development of AD in women.