After a brief overview of the size and nature of illicit drug use observed among American adolescents and young adults over the past 20 years, this paper argues that the nation's reliance on supply reduction as its primary strategy for controlling drug abuse has been unsuccessful. Of the two approaches to demand reduction--coercive techniques versus changing beliefs, attitudes, and norms--the latter, and primary prevention in particular, are judged most promising. The paper discusses three essential components to the process of early intervention: idea generation, program development, and systematic evaluation. The report examines the two most far-reaching current approaches to prevention--school-based programs and media-based efforts; the report then offers recommendations. The study also presents a number of specific ideas for expanded approaches to prevention. These include emphasis on health and other risks associated with various substances; early creation of parent groups; recreational alternatives for adolescents to "partying" organized around substance use; systematic attempts to change norms among adolescents regarding drug use; and a serious societal response to the adverse effects of widespread alcohol and cigarette advertising. The drug-related beliefs and attitudes of young people are examined, and procedures for changing those beliefs are suggested. (TE)