Prevention is the promotion of constructive lifestyles and norms that discourage alcohol, tobacco and other drug (ATOD) abuse.

Prevention is achieved through the application of multiple strategies; it is an ongoing process that must relate to each emerging generation.

Many prevention approaches, such as selective prevention strategies, focus on helping individuals develop the knowledge, attitudes, and skills they need to make good choices or change harmful behaviors. Many of these strategies can be classroom-based.

Universal prevention approaches include the use of environmental prevention strategies, which are tailored to local community characteristics and address the root causes of risky behaviors by creating environments that make it easier to act in healthy ways. The successful execution of these strategies often involves lawmakers, local officials, and community leaders, as well as the acceptance and active involvement of members from various sectors of the community (such as business, faith, schools, and health). For example, the use of this type of strategy may offer fewer places for young people to purchase alcohol, so consuming alcohol becomes less convenient; therefore, less is consumed.

Environmental change strategies have specific advantages over strategies that focus exclusively on the individual. Because they target a much broader audience, they have the potential to produce widespread changes in behavior at the population level. Further, when implemented effectively, they can create shifts in both individual attitudes and community norms that can have long-term, substantial effects. Strategies that target the environment include communication, education, and enforcement.