Despite increasing cannabis potency in Europe, the severity of emergency department visits for cannabis toxicity stayed the same over 10 years
Across 40 European emergency departments over a decade, the clinical severity of lone cannabis intoxication presentations remained largely stable despite documented increases in cannabis potency.
Quick Facts
What This Study Found
Among 3,839 ED presentations for lone cannabis toxicity (2013-2022), the most common symptoms were anxiety (35%), agitation (22%), decreased alertness (21%), and vomiting (20%). Very few statistically significant changes in clinical features occurred over time. Severity markers (ambulance transfer 76%, hospitalization 13%, ICU 1%, death 0.1%) showed no significant time trends in linear or nonlinear models.
Key Numbers
3,839 ED presentations across 40 EDs in 25 countries. Median age 25, 71% male. Anxiety 35%, agitation 22%, decreased alertness 21%, vomiting 20%. Seizures, arrhythmias, hyperthermia each < 3%. Hospitalization 13%, ICU 1%, death 0.1%. Only hypotension and hypertensive crisis showed significant increasing trends.
How They Did This
Secondary analysis of the Euro-DEN Registry across 40 emergency departments in 25 European countries from October 2013 to December 2022. Only presentations with lone cannabis use (no alcohol or other drugs detected) were included. Time trends for 14 clinical signs and 4 severity markers were analyzed using linear and nonlinear models.
Why This Research Matters
The common assumption that higher-potency cannabis products lead to more severe emergency presentations is not supported by this large European dataset. This matters for public health messaging: potency concerns are valid, but the clinical severity picture at the emergency level has remained stable.
The Bigger Picture
Cannabis potency has been a major policy talking point. This study suggests that while potency increases are real, they have not translated into measurably worse outcomes in emergency settings, potentially because users self-titrate or because acute cannabis toxicity has a ceiling effect.
What This Study Doesn't Tell Us
Relies on ED presentations, which may miss cases that resolve without medical attention. Drug testing varied across centers. Changes in user behavior (self-titration) could mask potency effects. Euro-DEN may not capture all acute cannabis presentations.
Questions This Raises
- ?Are users self-titrating to compensate for higher potency?
- ?Would the picture differ for edibles, which have different toxicity patterns?
- ?Could increasing potency still affect long-term outcomes without changing acute presentations?
Trust & Context
- Key Stat:
- No significant change in hospitalization, ICU admission, or death rates from cannabis toxicity over 10 years
- Evidence Grade:
- Large multi-country registry with decade-long data and rigorous trend analysis, though voluntary reporting and variable testing across centers introduce some uncertainty.
- Study Age:
- 2026 publication covering Euro-DEN data from 2013-2022
- Original Title:
- Changes in clinical features and severity in patients presenting to European emergency departments with acute cannabis toxicity over the 10-year period from 2013 to 2022.
- Published In:
- Addiction (Abingdon, England), 121(2), 316-330 (2026)
- Authors:
- Miró, Òscar(2), Galicia, Miguel(2), Dargan, Paul I(6), Wood, David M, Dines, Alison M, Heyerdahl, Fridtjof, Hovda, Knut Erik, Giraudon, Isabelle, Yates, Christopher, Liechti, Matthias, Vallersnes, Odd Martin, Eyer, Florian, Burillo-Putze, Guillermo
- Database ID:
- RTHC-08494
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Does this mean high-potency cannabis is safe?
Not necessarily. This study found that emergency department presentations did not worsen, but it does not address long-term mental health effects, dependency, or other non-acute harms that potency may influence.
What symptoms do people show up with?
The most common were anxiety (35%), agitation (22%), drowsiness or reduced consciousness (21%), and vomiting (20%). Serious events like seizures and cardiac arrhythmias were rare (under 3%).
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Cite This Study
https://rethinkthc.com/research/RTHC-08494APA
Miró, Òscar; Galicia, Miguel; Dargan, Paul I; Wood, David M; Dines, Alison M; Heyerdahl, Fridtjof; Hovda, Knut Erik; Giraudon, Isabelle; Yates, Christopher; Liechti, Matthias; Vallersnes, Odd Martin; Eyer, Florian; Burillo-Putze, Guillermo. (2026). Changes in clinical features and severity in patients presenting to European emergency departments with acute cannabis toxicity over the 10-year period from 2013 to 2022.. Addiction (Abingdon, England), 121(2), 316-330. https://doi.org/10.1111/add.70233
MLA
Miró, Òscar, et al. "Changes in clinical features and severity in patients presenting to European emergency departments with acute cannabis toxicity over the 10-year period from 2013 to 2022.." Addiction (Abingdon, 2026. https://doi.org/10.1111/add.70233
RethinkTHC
RethinkTHC Research Database. "Changes in clinical features and severity in patients presen..." RTHC-08494. Retrieved from https://rethinkthc.com/research/miro-2026-changes-in-clinical-features
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.