The 25th anniversary of the French Observatory for Drugs and Drug Addiction Vol. 27, 2021/3 - pagesPages 5 to 10The 25th anniversary of the French Observatory for Drugs and Drug Addiction By Michel HautefeuillePages 11 to 33Objectivity, regularity, accessibility: what is the role for a public observatory in the field of drugs and addictive behaviour?By Julien Morel d’ArleuxPages 35 to 64Drugs and addictions: 20 years of developments in France (2000-2020)By Ivana ObradovicPages 65 to 86A look back at 20 years of quantifying drug use among adolescentsBy Stanislas Spilka, François BeckPages 87 to 112Free party, counterculture, drug uses, harm reduction, repressive measuresBy Clément Gérome, Fabrice Guilbaud