The aim of this study was to identify the latest trends in psychotropic drug use and the effect of the increase of maintenance treatments for serious opioid addiction. The results are based on data from OPPIDUM, an annual survey primarily concerned with the consumption of licit and illicit drugs. The study involved 1066 drug addicts recruited during the month of October 1997 from 38 French health centres connected with the Centres for Evaluation and Information on Drug Addiction (CEIP). The most frequently reported drugs were benzodiazepines (n = 323), some of which, especially flunitrazepam (Rohypnol, n = 123), are extremely addictive. The data showed a slight decrease in heroin consumption as well as a marked increase in the use of maintenance treatments. The association between benzodiazepines and buprenorphine (Subutex) should consequently be studied, whether buprenorphine is being used illicitly or prescribed as a maintenance treatment.