According to a wealth of epidemiological literature, drug use appears to be strongly linked to urbanization and population density. However, these studies primarily focus on an adult population, most often marginalized. What about the adolescent population? To explore this question, the OFDT has been conducting since 2004 an original research project based on a municipal adaptation of the national ESCAPAD survey (the latter having been presented at the fourth Francophone conference on surveys). In 2004, using the entire methodology and questionnaire from the national ESCAPAD survey, the OFDT conducted a representative survey of a sample of more than 1,500 17-year-old Parisian adolescents residing within the city limits of Paris. Knowing the district of residence of the respondents made it possible to compare geographical and social disparities with the data on psychoactive substance use observed in the survey. [excerpt from presentation]