A crucial component of the "War on Drugs" is to provide interventions to at-risk individuals before they develop serious problems with substance use. In the 1990s, we have seen a dramatic increase in the quantity and quality of scientific research on the advancement of prevention science. Documenting the accomplishments of the leading researchers in the field and setting the stage for future progress in prevention science are the foci of Prevention and Societal Impact of Drug and Alcohol Abuse.