Reports of adverse events from recreational cannabis tripled in France between 2012 and 2017 | Research

The takeaway

Adverse event reports from recreational cannabis tripled in France over six years, with psychiatric effects (51.2%) most common and cannabinoid hyperemesis syndrome emerging as a new concern.

Healthcare providers, public health officials, cannabis users, anyone interested in cannabis safety data

Adverse event reports tripled from 179 to 562 per year

What the researchers found

Cannabis adverse event reports tripled from 179 (2012) to 562 (2017), totaling 2,217 cases. Psychiatric effects were most common (51.2%), followed by neurological (15.6%), cardiac (7.8%), and gastrointestinal (7.7%). Dependence ranged from 10-20% of reports. Cannabinoid hyperemesis syndrome (87 cases) emerged from 2015. Seven deaths were reported.

Why it matters

This surveillance data provides one of the more comprehensive pictures of cannabis adverse events from a national reporting system, documenting the full spectrum of harms including the emergence of cannabinoid hyperemesis syndrome.

The numbers in context

2,217 total cases; 76.4% male; 18-34 age group most common; 71.6% inhaled; 64.2% chronic use; dependence 10-20%; 87 hyperemesis cases; 34 unexpected AEs; 7 deaths

How the study worked

Analysis of adverse events from recreational cannabis use reported to the French Addictovigilance Network from 2012 to 2017, excluding CBD and synthetic cannabinoids.

What this study cannot tell us

Voluntary reporting systems underestimate true adverse event rates. Increase in reports may partly reflect improved awareness and reporting rather than increased harm. Cannot determine causation from surveillance data alone.

How to read the evidence

National surveillance data from a formal pharmacovigilance network over six years

When this study was published

Published in 2021 using 2012-2017 French surveillance data. Cannabis remains illegal for recreational use in France.

The bigger picture

The tripling of adverse event reports likely reflects both increasing cannabis use and better reporting. The emergence of cannabinoid hyperemesis syndrome as a recognized condition illustrates how surveillance systems can identify new health concerns.

Questions still open

Is the increase in reports proportional to increased cannabis use or are adverse events becoming more common per user? How does the French adverse event profile compare to countries with legal cannabis? What is the true incidence of cannabinoid hyperemesis syndrome?

Common questions

What are the most common adverse effects of cannabis?

In this French surveillance study, psychiatric effects were most common (51.2%), followed by neurological problems (15.6%), cardiac issues (7.8%), and gastrointestinal effects (7.7%). Dependence was reported in 10-20% of cases.

What is cannabinoid hyperemesis syndrome?

A condition involving severe cyclic vomiting associated with chronic cannabis use. It emerged in the French reporting system from 2015, with 87 cases documented through 2017.

Read the original research

Adverse events of recreational cannabis use reported to the French addictovigilance network (2012-2017).

British journal of clinical pharmacology, 87(10), 3925-3937

View on PubMed ↗Publisher’s paper ↗

Citation

Bouquet, Emilie; Pain, Stéphanie; Eiden, Céline; Jouanjus, Emilie; Richard, Nathalie; Fauconneau, Bernard; Pérault-Pochat, Marie-Christine. (2021). Adverse events of recreational cannabis use reported to the French addictovigilance network (2012-2017).. British journal of clinical pharmacology, 87(10), 3925-3937. https://doi.org/10.1111/bcp.14812