This study examined emergency department admissions changes for cannabis-induced psychosis and schizophrenia and related conditions in Canada after they legalized adult-use cannabis nationwide in 2018. It was published in the Canadian Journal of Psychiatry in August 2022.
The study used data from ALL emergency department admissions in Alberta and Ontario during the time period.
- "key indicators of patterns of cannabis use in Alberta and Ontario showed relatively little change after legalization."
- "there was no evidence of post-legalization change in the prevalence among individuals who use cannabis daily/almost daily (7.2% vs. 7.1%)"
- "The current study found no evidence that Canada's first phase of cannabis legalization was associated with significant changes over the 14.5-month post-legalization period in Ontario/Alberta emergency department presentations for either cannabis-induced psychosis or schizophrenia."
The full text analysis is here at PubMed Central.