CHS emergency visits doubled after cannabis legalization and rose further during COVID-19
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.
Quick Facts
What This Study 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.
Key Numbers
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 They Did This
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.
Why This Research 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 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.
What This Study Doesn't 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.
Questions This Raises
- ?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?
Trust & Context
- Key Stat:
- CHS emergency prevalence doubled from pre-legalization to COVID-19 period
- Evidence Grade:
- Combines population-level administrative data with patient survey data, though each component has limitations.
- Study Age:
- Published in 2022 covering 2017-2021.
- Original Title:
- Cannabinoid hyperemesis syndrome in North America: evaluation of health burden and treatment prevalence.
- Published In:
- Alimentary pharmacology & therapeutics, 56(11-12), 1532-1542 (2022)
- Authors:
- Andrews, Christopher N(2), Rehak, Renata, Woo, Matthew, Walker, Ian, Ma, Christopher, Forbes, Nauzer, Rittenbach, Katherine, Hathaway, Joshua, Wilsack, Lynn, Liu, Andy, Nasser, Yasmin, Sharkey, Keith A
- Database ID:
- RTHC-03675
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Is CHS becoming more common?
In Alberta, CHS-related ER visits more than doubled over 3 years, from 15 per 100,000 before legalization to 32 per 100,000 during COVID-19.
Do CHS patients have cannabis addiction?
In this survey, 100% of CHS patients met criteria for cannabis use disorder, and most also screened positive for anxiety (59%) and depression (68%).
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Cite This Study
https://rethinkthc.com/research/RTHC-03675APA
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
MLA
Andrews, Christopher N, et al. "Cannabinoid hyperemesis syndrome in North America: evaluation of health burden and treatment prevalence.." Alimentary pharmacology & therapeutics, 2022. https://doi.org/10.1111/apt.17265
RethinkTHC
RethinkTHC Research Database. "Cannabinoid hyperemesis syndrome in North America: evaluatio..." RTHC-03675. Retrieved from https://rethinkthc.com/research/andrews-2022-cannabinoid-hyperemesis-syndrome-in
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.