This report presents the recommendations of a WHO Expert Committee responsible for reviewing information on dependence-producing drugs to assess the need for their international control. The first part of the report contains a summary of the Committee's evaluations of seven substances (dronabinol, oripavine, buprenorphine, butorphanol, ketamine, khat, and zopiclone). The report also discusses the substances that were pre-reviewed (gamma-hydroxybutyric acid and tramadol) and recommended gamma-hydroxybutyric acid for critical review at a future meeting. Two substances (gamma-butyrolactone and 1 4-butanediol) were identified for future pre-review). The second part of the report discusses the guidelines for the WHO review of dependence-producing psychoactive substances for international control. It includes sections on amending the current guidelines, interpretation of specific aspects of the guidelines and access to information necessary for the evaluation of substances. The final section considers other matters including activities of the EMCCDA, the use of pharmacovigilance data, promotion of education and information on the appropriate use of psychoactive drugs, and the impact of international control on medical availability of substances.