Citation

Di Forti M. World Psychiatry 2020; 19(2): 188-189.

Affiliation

Department of Social, Genetic and Developmental Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.

Copyright

(Copyright © 2020, World Psychiatric Association, Publisher John Wiley and Sons)

DOI

10.1002/wps.20737

PMID

32394550

Abstract

The wave of changes in cannabis laws coming from the US and more recently Canada has pushed many countries, including the land of Shakespeare, into the dilemma of legalizing or not legalizing cannabis use.

In the UK, a first step took place in November 2019, when medicinal cannabis became legal. Now British specialist physicians can prescribe cannabis for a handful of medical conditions. However, has the American experiment yet convinced its more cautious British allies to go all the way and legalize cannabis for recreational use?

As a clinician and an academic living in UK and working on the link between cannabis use and psychotic disorder, I have been watching the American experiment very closely.

Hall and Lynskey1 highlight that two of the key arguments of the legalization lobby are: a) that it will reduce adolescent access, and b) that the available cannabis will be ­safer and less potent because of state‐con­trolled levels of its active ingredient, tetra­hydrocannabinol (THC). These are clever­ly chosen predictions to reassure both con­cerned parents and mental health professionals against the well‐established association between cannabis use – especially when started in adolescence2 and of high potency types3 – and the risk to develop a psychotic disorder. But, have these two predictions held up against the evidence of time?

Hall and Lynskey give a comprehensive snapshot of the outcomes that have followed the changes in cannabis law since 2012 in the US. So, what about adolescents use?

The authors report that, while rates of cannabis use have increased among adults in states that have legalized cannabis, they have not changed among adolescents. Not surprisingly, as Canada, Uruguay and the US have legalized cannabis for adult use, whereas use remains illegal for adolescents, the latter continue to buy it from criminal gangs and they risk criminal prosecution for using it. Moreover, experience with both tobacco and alcohol has shown that adolescents’ choices are not influenced as much as adults’ by the legal status of a recreational drug. Furthermore, it is still early days to see whether the increase in rates of cannabis use among adults leaks down to influence younger groups ...

Language: en