The study, published in the International Journal of Drug Policy, delved into regional changes in health services use and incidences of psychotic disorders in the immediate aftermath of Canada’s cannabis legalization in October 2018, advocacy group NORML report.
Contrary to concerns, the researchers said: “We did not find evidence of increases in health service use or incident cases of psychotic disorders over the short-term (17 month) period following cannabis legalization.”
This finding aligns with a 2022 study published in the Canadian Journal of Psychiatry, which concluded that the implementation of Canada’s cannabis legalization framework did not correlate with significant changes in cannabis-induced psychosis or schizophrenia emergency department presentations.
The study’s scope covered a 17-month period post-legalization, and while it provides valuable insights, the researchers underscore the need for a more extended post-legalization observation period to fully comprehend the population-level impacts of non-medical cannabis legalization.
The Canadian findings are also in line with the situation in the United States, where state-level cannabis legalization laws haven’t demonstrated a statistically significant increase in psychosis-related health outcomes. A 2022 paper in the Journal of the American Medical Association (JAMA) Network Open found no association between the adoption of cannabis legalization and overall rates of psychosis-related diagnoses or prescribed antipsychotics.