History shows that humankind has always had an appetite for psychoactive substances. Since young people are especially vulnerable to drug abuse, the etiology, epidemiology, and prevention literature on substance use by school-aged children are examined in this booklet. It gives information on, and examples of, preventive approaches and programs in schools and communities in addition to providing guidelines for preventive work. Because of the diversity of substance use and prevention goals around the world, the information and guidelines presented here are stated in general terms. The book opens with an overview of drinking, providing examples of drinking behavior, drinking styles, and risks associated with alcohol use. Drug use among young people is discussed next, including reasons why young people use drugs. Tobacco use by children is then examined, along with determinants of tobacco use and the harm tobacco can cause. Prevention is the focus of the text and examples of health promotion within schools are provided. Tips on working with community members, working with other agencies, and working with parents are offered. Emphasis is also placed on education in the schools, on policies for developing prevention in schools, and on youth organizations, such as community sports clubs and prevention clubs. (RJM)