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Cannabis Review for the attention of the WHO


Cannabis in a jar

The scheduling under the Single Convention on Narcotic Drugs assumes a scientific justification. However, cannabis and cannabis resin have never been evaluated by the World Health Organisation (WHO) since it was mandated the review of psychoactive substances in 1948. The last evaluation for the international substance control conventions were therefore when the League of Nations evaluated them in 1924 and 1935.


In 80 years since that decision, both the social context of cannabis use and the science of drug dependence have dramatically changed. Yet, because there has never been a formal review, both herbal cannabis and cannabis resin continue to remain under the strictest drug control regime possible. As a result, in the absence of a recent scientific assessment, the continued prohibition of cannabis is completely illegitimate even though it may be legal.


With this wide ranging report (discussing topics from its effects on cognition and learning to mental health and therapeutic benefits), DrugScience enhances the ability of the WHO and its Expert Committee on Drug Dependence (ECDD) in fulfilling its international obligations and enables the Expert Committee to arrive at an independent and scientific recommendation whether a Critical Review is warranted or not.


The report does not come to conclusions on scheduling of cannabis in the international drug control conventions, as this is the prerogative of the ECDD.

Committee recommendations are needed on the following topics:


1. Whether a Critical Review should be conducted for reviewing the current scheduling in Schedules I and IV. Each of the following reasons would justify a recommendation for a Critical Review:


a. because WHO has never conducted a Critical Review, meaning that there is no scientific justification for the current scheduling; b. because the wide-spread medical use, including the use of preparations with a marketing authorization is in contradiction to listing in Schedule IV; c. because it is not clear whether the dependence-producing properties of cannabis and cannabis resin are between codeine and morphine (justification for Schedule I) or between dextropropoxyphene and codeine (justification for Schedule II) or below those of dextropropoxyphene (justification for not scheduling).


2. On the medical use of cannabis and its preparations (which can include revoking old recommendations by the Committee)


3. On the need of quality control on cannabis and cannabis products for medical and non-medical use.

This report was prepared by DrugScience in anticipation of the DrugScience presentation to the WHO ECDD 2016. It was not commissioned by the ECDD Secretariat or WHO. The authors alone are responsible for the views expressed in this report and they do not necessarily represent the decisions, policy, or views of the ECDD Secretariat or the WHO.


Update – 30/11/2016



At the 37th ECDD meeting the Committee requested that Secretariat begin collecting data towards a pre-review of cannabis, cannabis resin, extracts and tinctures of cannabis at a future meeting. Consistent with this request, two updates on the scientific literature on cannabis were prepared and subsequently presented to the Expert Committee. Following its deliberations the Committee noted that the current Schedule I of the 1961 Convention groups together cannabis and cannabis resin, extracts and tinctures of cannabis. Cannabis plant and cannabis resin are also in Schedule IV of the 1961 Convention. The Committee further noted that there are natural and synthetic cannabinoids in Schedule I and Schedule II of the 1971 Convention. The committee recognized:


  1. An increase in the use of cannabis and its components for medical purposes

  2. The emergence of new cannabis-related pharmaceutical preparations for therapeutic use

  3. Cannabis has never been subject to a formal pre-review or critical review by the ECDD.


The Committee requested that the Secretariat prepare relevant documentation in accordance with the Guidance on the WHO review of psychoactive substances for international control in order to conduct pre-reviews for the following substances:


  1. Cannabis plant and cannabis resin

  2. Extracts and tinctures of cannabis

  3. Delta-9-tetrahydrocannabinol (THC)

  4. Cannabidiol (CBD)

  5. Stereoisomers of THC.

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