A major focus of alcohol research is to identify children and adolescents who are at risk of developing alcohol problems. To the extent that such children can be identified, prevention and early intervention efforts have the potential to preclude or mitigate problematic drinking and its associated consequences. These consequences are not only concurrent but also cumulative. That is, beyond the immediate consequences of excessive alcohol use in adolescence—academic problems, poisoning, risky sex, motor vehicle accidents, suicides, and so on—the accretion of these consequences also reduces legitimate avenues to success in adulthood, disrupting key processes of brain development and increasing the likelihood of disability, unemployment, relationship problems, and criminal behavior.1–3