While drug control laws tend to reduce the incidence of drug use, their enforcement is not without cost to society. Among the most obvious costs is the development of black markets in drugs and the criminalization of users. Modest control laws can substantially reduce drug use without incurring serious social costs. However, increasing the severity of control laws adds less and less to the benefits achieved and more and more to the costs to society. Ultimately the costs outweigh the benefits. We should aim for optimum levels of control by weighing both the benefits and costs of our drug control laws.
Efficacy evaluation of the school program Unplugged for drug use prevention among Brazilian adolescents