The Critical Review is the official mechanism by which a committee of experts called for the special occasion, within the World Health Organization (WHO), revises all the existing data and knowledge about a narcotic drug. This Expert Committee on Drug Dependence (ECDD) analyzes the information in order to establish the real potency, the assessed therapeutic effects, and the real health or social harms and risks that can be produced by each “narcotic” plant or substance. After making a Critical review, the ECDD delivers to the United Nations system and to the governments of the world a recommendation on the level of control to be applied.

Nowadays, Cannabis is still scheduled as a substance liable to abuse and highly addictive, with particularly dangerous properties and little or no therapeutic values (Schedules I and IV of the 1961 Single Convention), just as heroin. Despite the discovery of THC in the 1960’s, despite the discovery of the endocannabinoid system in the 1990’s, despite the growing number of diseases for which Cannabis is scientifically proven to have an useful therapeutic effect, Cannabis has not had any critical review since the year 1935 ! Yet in 1965, the ECDD (Expert Committee on Drug Dependance) made a pre-review that did not lead to any result, and in 1991, the ECDD recommended the descheduling of THC from the list of most harmful substances.


Today, the whole plant has to be descheduled from the tables I and IV of the 1961 Single Convention on Narcotic Drugs, the very international lock against any Cannabis policy reform at national level. But this have to be assessed by a Critical review by the ECDD, 81 years after the previous one. Many civil society organizations have been working on this issue for years, and today, the United Nations General Assembly, in the recent Special Session on the world drug problem (UNGASS 2016) recognizes the need of a renewed, balanced and scientific evidence-based approach towards the international scheduling system, by reaffirming the treaty-mandated role of WHO, but also resolving to “[support] scientific evidence-based review and scheduling of the most prevalent, persistent and harmful substances” as well as calling for “informed and coordinated scheduling decisions”.

The World Health Assembly (WHA) is the place and moment where most of the decisions concerning the ECDD are made. This year’s 69th WHA will take place from 23rd to 28th of May, in Geneva’s Palais des Nations, and includes an agenda item on the public health approach of drug policies, in the context of UNGASS.

It is time to advocate for a concrete change of paradigm in the international drug control system, towards  an evidence-based approach to policies, starting with the long overdue Critical review of the most used and one of the less harmful substances : Cannabis.

Expert Committee on Drug Dependence (ECDD)

Photo credit : IDPC

Photo credit : IDPC

The ECDD is a body of experts responsible for conducting the medical and scientific evaluation of dependence-producing substances, and for making recommendations concerning the level of international control to be applied to the UN Commission on Narcotic Drugs, the international legislative organ on narcotic drugs. In theory, no psychoactive substance can be scheduled internationally without first being evaluated by this expert committee of the WHO.

We can emphasize that the evaluation of substances by this committee is one of the few tasks of WHO, if not the only one, based on international treaties. It is a mandatory task.

The name of the committee is set since 1969, but before that, the committee has existed under various names :

  • 1969: Expert Committee on Drug Dependence.
  • 1966: Expert Committee on Dependence-Producing Drugs.
  • 1964: Expert Committee on Addiction-Producing Drugs.
  • 1950: Expert Committee on Drugs Liable to Produce Addiction.
  • 1949: Expert Committee on Habit-Forming Drugs established.

Before that, an expert committee, associated to the International Office for Public Health, made substances reviews and scheduling recommendations for the consideration of the League of Nations. Cannabis was reviewed under this League of Nations expert committee in 1935.

The article « Modernizing methodology for the WHO assessment of substances for the international drug control conventions » by E. Danenberg, L.A. Sorge, W. Wieniawski, S. Elliott, L. Amato and W.K. Scholten, published in Drug and alcohol dependence 131 (2013) 175–181, says :

After the WHO Executive Board rejected proposals for Supplementary guidelines twice, the Secretariat developed a major revision of the guidelines in force, addressing the issues that the Supplementary guidelines were sup- posed to address, but also paying attention to transparency of the process and the use of the internet. With the adoption of the Guidelines for the WHO Review of Psychoactive Substances for International Control by the Executive Board, the procedures to fol- low by the ECDD for abuse liability assessment are clearly defined and it requires that the approach is evidence-based. The procedure is centered around matters of public health to consider if a substance should be placed in the Single Convention on Narcotic Drugs, 1961 (Schedule I or II) or the Convention on Psychotropic Substances, 1971 (Schedule I, II, III or IV). Evaluation of a substance is undertaken by the ECDD and utilizes data provided by the WHO Secretariat. Overall, the review procedure considers a substance’s similarity to substances already in the 1961 or 1971 Conventions as well as a substance’s degree of therapeutic usefulness and impact on public health through its liability of abuse.

Since its first meeting 50 years ago, the ECDD has played a central role in the international drug control system. Its main task is to carry out medical and scientific evaluations of the abuse liability of dependence-producing drugs falling within the terms of the 1961 Single Convention on Narcotic Drugs and the 1971 Convention on Psychotropic Substances. It then makes recommendations to the United Nations Commission on Narcotic Drugs on the control measures, if any, that it considers appropriate. The Expert Committee’s reports are published by WHO in its Technical Report Series.


WHO review of psychoactive substances for international control





Source : « Guidance on the WHO review of psychoactive substances for international control« , WHO, 2010.

In their Series of Legislative Reform of Drug Policies #25, the Trans-National Institute and the International Drug Policy Consortium provide an interesting condensed schema of the schedules of the 1961 and 1971 conventions :



Source : « Scheduling in the international drug control system« , TNI & IDPC, 2014.