Instead of being regarded as a health or discipline problem that involves only a few deviant adolescents, drug use has begun to be viewed in the last decade as social behavior that is functional for adolescents, not capricious, and is normative for the population. The most successful prevention programs have sought to delay the onset of tobacco use. They have targeted factors predictive of adolescent smoking, alcohol, and drug use. The programs teach adolescents why people their age smoke tobacco or use alcohol and drugs; how these meanings are established by peers, older role models, and advertising; how to resist these influences; and life skills and competencies to counterbalance the functions that drug use serves. These strategies are being studied for preventing use of alcohol and other drugs. In addition, elected peer leaders are trained to conduct these activities and serve as role models. Results are shown by studies of the Minnesota Smoking Prevention Program and in northern California, revealing 50-70 percent reductions in the onset of smoking. In addition, Botvin's Life Skills Training Program demonstrates success in delaying heavy alcohol and marijuana use. 6 references. (Author abstract modified)