As long as there is a market for drugs, there will be people to supply them. To attack the source of the problem, the demand for drugs must be eliminated. Drugs will never disappear, so people need to learn to live in a world that includes them. Our society has accepted the continued existence of tobacco and alcohol despite the harm they cause. Programs should be evaluated according to how many students in the program later tried drugs. Until the early 1970s, most drug prevention programs were not evaluated. Goal of presenting negative information about drugs in schools = prevention of use. Public health model: primary, secondary, and tertiary prevention. Aimed at young people who have not yet tried the substances in question. May encourage abstinence and help teach people how to view the potential influence of drugs on their lives, emotions, and social relationships.