Adolescence is often a time for experimenting with psychoactive substances and sometimes marks the transition to more regular use. Drawing on the results of general population surveys conducted in France, this article provides an overview of drug use among younger adolescents, highlighting how their patterns differ from those of older adolescents. It shows that regular use of various substances generally does not begin until around age 14, but that adolescents who experiment at an early age are at a significantly higher risk of transitioning to more intensive or problematic use. By presenting the methodological limitations of the surveys used, the authors discuss the nature of the observed link between early experimentation and level of use: while noting the indisputable predictive value of early first use in forecasting future problematic use, they show that interpreting this link can be challenging in cross-sectional epidemiological surveys.[author abstract]