Do we need to reform international drug treaties as more countries legalise cannabis?

The future of international drug control treaties is in doubt because of recent treaty-violating decisions to legalize cannabis use in Canada, the United States and Uruguay.  Professor Wayne Hall, whose 2014 review of 20 years of cannabis research made world headlines, thinks so. If decriminalization is the way of the future, Hall advocates a cautious approach to policy reform that would involve trialling and evaluating the effects of incrementally more liberal drug policies. His suggestions, outlined below, are published online today by the scientific journal Addiction.

The international drug control treaties are endorsed by most member states of the United Nations (UN).  The treaties prohibit the non-medical use of amphetamines, cannabis, cocaine and heroin.  They aim to reduce the harmful use of prohibited drugs and facilitate access to these drugs for medical and scientific purposes.  Critics claim that the treaties have failed to tackle non-medical use of prohibited drugs and have justified policies that conflict with UN human rights treaties by incarcerating large numbers of drug users.

Hall's paper outlines types of policies that nations could adopt to address the different types of harm that different illicit drugs cause to users and others.  Some would require treaty change, while others could be accomplished by more 'flexible interpretations' of treaty provisions by member states and UN agencies.  His suggestions are:

  • Cannabis: This is the strongest candidate for national policy experiments on different ways of regulating its sale and use. This is happening in the USA, Uruguay and Canada. Rigorous evaluations of these experiments will be useful for other countries considering legalizing cannabis for adult recreational use.
  • Party drugs, such as ecstasy, LSD, and novel psychoactive substances:  The most important regulatory challenge for those who advocate more liberal policies is ensuring that drug manufacture and sale meet reasonable standards of consumer safety and consumers are well informed about the risks of using these drugs.
  • Opioids:  The best way forward may be a mitigated form of prohibition.  Mitigated prohibition differs from a 'war on drugs' by expanding treatment for opioid dependence, reducing some of its serious medical complications, and reducing the number of opioid users who are imprisoned.
  • Cocaine and amphetamines:  There are no easy answers here.  Proposed regulation via a modified prescription system seems unlikely to reduce harmful use. Prohibition may minimize use but it is not sufficient, because stimulants are very easy to produce illicitly. Stimulant policy needs better ways of reducing the demand for stimulants and more effective treatments for problem stimulant users.

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For editors:

Hall W (2017) The future of the international drug control system and national drug prohibitions. Addiction 112. doi: 10.1111/add.13941

Professor Wayne Hall has made large contributions in the field of public health in the area of drug use, addiction, treatment, ethics, and research as World Health Organization's expert adviser. As a "Highly Cited Author" identified by the Institute for Scientific Analysis, he is dedicated to public health research. His research interests include alcohol and drug research and education, cancer prevention, epidemiology, health policy, mental health, pharmacoeconomics and policy, and tobacco control. 

Media seeking interviews with Professor Wayne Hall should contact him via the University of Queensland by email ( or telephone (+61 7 336 55246).

Addiction is a monthly international scientific journal publishing peer-reviewed research reports on alcohol, illicit drugs, tobacco, and gambling as well as editorials and other debate pieces. Owned by the Society for the Study of Addiction, it has been in continuous publication since 1884. Addiction is the number one journal in the 2016 ISI Journal Citation Reports ranking in the substance abuse category for both science and social science editions.