The initiation and continuation of alcohol use by an individual is influenced by numerous factors, chiefly the individual’s genetic makeup, the environments to which he or she is exposed, and complex mechanisms through which genes interact with one another and with the environment. These same factors determine an individual’s pattern of alcohol consumption and the risks for developing alcohol dependence (alcoholism) or other alcohol use disorders.

Research has also revealed that neither genetic nor environmental factors are static. That is, the emergence and progression of drinking behavior and of drinking consequences are influenced by multiple ongoing changes in biology, physiological and psychological development, and environment that occur over the course of a person’s life. These observations are in accord with a broader recognition that human development continues throughout life, rather than stopping after adulthood is reached. The influence of alcohol on biology and behavior is dynamic and changes as an individual moves from childhood into adolescence and through the various stages of adulthood.