CHS-related emergency visits in Alberta more than doubled from 15 to 32 per 100,000 population between pre-legalization and the COVID-19 pandemic period, with 100% of surveyed CHS patients meeting criteria for cannabis use disorder.
Emergency physicians, gastroenterologists, addiction medicine specialists, and public health officials.
CHS emergency prevalence doubled from pre-legalization to COVID-19 period
What the researchers found
CHS treatment prevalence increased from 15/100,000 pre-legalization to 21/100,000 post-legalization to 32/100,000 during COVID (p<0.001). Among chronic cannabis users aged 16-24, prevalence reached 6/1,000. Survey data showed universal cannabis use disorder (CUDIT-R >=8), with 59% screening for moderate anxiety and 68% for depression.
Why it matters
The steep increase in CHS treatment prevalence over just 3 years, especially during COVID-19, signals a rapidly growing healthcare burden that clinicians need to recognize and manage.
The numbers in context
Survey: 157 CHS patients. CUDIT-R >=8: 100%. Moderate+ anxiety: 59%. Moderate+ depression: 68%. Alberta ED prevalence: 15 pre-legalization, 21 post-legalization, 32 during COVID per 100,000. Ages 16-24: 6 per 1,000 chronic users.
How the study worked
Two-part study: (1) internet survey of 157 CHS sufferers in Canada and US, and (2) administrative health database analysis for Alberta (population 5 million) examining ED visits for vomiting with cannabis use codes across three time periods.
What this study cannot tell us
Survey sample was self-selected. Administrative data may undercount CHS due to coding variability. COVID-19 period may have altered ED-seeking behavior. Cannot separate legalization effects from temporal trends.
How to read the evidence
Combines population-level administrative data with patient survey data, though each component has limitations.
When this study was published
Published in 2022 covering 2017-2021.
The bigger picture
The universal cannabis use disorder among CHS patients suggests that CHS may be a marker of severe cannabis dependence, not just heavy use, with important implications for treatment approach.
Questions still open
- What drove the additional COVID-19 increase: more cannabis use, more potent products, or pandemic-related stress? Why do some heavy cannabis users develop CHS while others do not?
Common questions
Is CHS becoming more common?
Do CHS patients have cannabis addiction?
Read the original research
Cannabinoid hyperemesis syndrome in North America: evaluation of health burden and treatment prevalence.
Alimentary pharmacology & therapeutics, 56(11-12), 1532-1542
Citation
Andrews, Christopher N; Rehak, Renata; Woo, Matthew; Walker, Ian; Ma, Christopher; Forbes, Nauzer; Rittenbach, Katherine; Hathaway, Joshua; Wilsack, Lynn; Liu, Andy; Nasser, Yasmin; Sharkey, Keith A. (2022). Cannabinoid hyperemesis syndrome in North America: evaluation of health burden and treatment prevalence.. Alimentary pharmacology & therapeutics, 56(11-12), 1532-1542. https://doi.org/10.1111/apt.17265
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