The most commonly used psychoactive substances have often been part of our societies for a long time. An initial set of measures to prevent addiction therefore involves modifying the environment to discourage their use through regulations or taxes. Another set of actions focuses on identifying users in order to help them reduce or stop their use. This involves, in particular, early detection and brief interventions. However, none of the measures listed above constitute prevention in the strict sense, which in principle involves preventing the onset of use rather than helping people stop. Cohort data show that early adverse events can increase the risk of psychoactive substance use. It is therefore important to draw on fifty years of prevention research, which has demonstrated the value of home visits before and after birth, parenting support programs, initiatives to improve the school environment in elementary school, and the development of psychosocial skills during adolescence. These broad-spectrum approaches, which are not specific to addiction prevention, also have the advantage of having a positive impact across many areas of social life.