The WHO Expert Committee on Drug Dependence (ECDD) is responsible for assessing psychoactive substances for possible control under the international drug control conventions. The ECDD reviews the therapeutic usefulness, the liability for abuse and dependence, and the public health and social harm potential of each substance under review. After the ECDD advises the Director-General of WHO as to whether to schedule or to amend the scheduling status of a substance, the Director-General will, as appropriate, communicate the recommendations to the United Nations Secretary-General. The Secretary-General communicates the advice to the Commission on Narcotic Drugs (CND), as appropriate. This report presents the recommendations of the thirty-seventh meeting of the WHO Expert Committee on Drug Dependence. The report summarizes the review of nine substances and the ECDD?s recommendations for the scheduling of seven substances. The report also provides updates on ketamine and cannabis, as requested byresolutions of the Commission on Narcotic Drugs. It contains updates on the work of international bodies concerned with controlled substances, as well as summaries of the follow-up discussions on recommendations made at the previous ECDD meeting, and on the discussions on criteria for assessing new psychoactive substances and on terminology.