The use of alcohol and other drugs is a worldwide problem, and has become a major concern and the target of social, political, psychological and scientific studies. A drug is any substance that is not produced by the body and which, when consumed, causes changes in the functioning of some of its systems. Drugs have always been present in people's lives, since ancient times, and their use has expanded and changed over the years. A distinction had to be made between the use and abuse of psychoactive substances in order to better meet the emerging demand. As a result, there was a need to create laws and public policies aimed at some kind of treatment and monitoring, ranging from a total ban on the use of psychoactive substances to the release of some of them, and harm reduction was brought in as an alternative. And it was through the Psychiatric Reform that began around 1970 that the debate on changes in the mental health sector significantly increased, thus allowing the construction of a new public policy on drugs.