FRANÇAIS :
La consommation de substances psychoactives (SPA) a des effets particulièrement néfastes chez les adolescents et jeunes adultes. Celle-ci demeure importante en Europe, en particulier en France, et dans les pays anglo-saxons, mais une tendance à la baisse commence à être observée. Il est important de suivre ces évolutions et d'essayer de les expliquer. À partir d'éléments de la littérature et de données d'enquêtes récentes conduites par l'Observatoire français des drogues et des toxicomanies et par Santé publique France, ce rapport dresse un panorama, non exhaustif, des évolutions et des usages de consommation de SPA chez les jeunes en France et à l'étranger, et présente des pistes explicatives des tendances observées.

ENGLISH:
Introduction: The use of psychoactive substances (PS) has particularly harmful effects on adolescents and young adults. This remains important in Europe, particularly in France, and in English-speaking countries, but a downward trend is being observed. It is integral to follow the evolution of use amongst these populations and to work towards explaining them.
Methodology: Based on elements from the literature and data from recent surveys conducted by the French Observatory of Drugs and Drug Addiction and by the French public health agency (Santé publique France), this report provides a non-exhaustive overview of consumer trends and uses among young people in France and abroad, and presents some explanatory tracks of the observed trends.
Results: In France, the number of 17-year-olds reporting never having used alcohol, tobacco and cannabis increased from 5.1% in 2008 to 11, 7% in 2017. There is also a decline in alcohol, tobacco and cannabis consumption among teenagers and young adults. The experimentation of illicit drugs (other than cannabis) among 17-year-olds remains fairly stable between 2014 and 2017 (around 6.8%). These developments are fairly similar in other European and Anglo-Saxon countries, but some Eastern European countries are an exception. [...]
Conclusion: It remains difficult to measure the contribution of each factor participating in the downward trend in consumption observed. Nevertheless, it seems important to continue to deploy public policies combining regulatory measures and prevention campaigns based on changes in representations and behaviors, to support and encourage the reduction of psychoactive substances that remain at fairly high levels among young people.