Researchers in Canada have examined the changes that occurred with cannabis abuse and use five years after recreational legalization compared to before.
Data from the study was collected by 1428 adult participants who completed up to eleven biannual assessments in Ontario between September 2018 and Oct 2023. They were analyzed in November 2023 and January 2024. The study assessed the frequency of use and misuse using Cannabis Use Disorder Identification Test – Revised (CUDIT-R) score.
Cannabis use disorder (CUD) is characterised by problematic patterns of behaviour resulting from use, and difficulties achieving cessation even though these problems exist – such as withdrawal symptoms.
Unlike some studies – particularly long-term ones – this cohort had a high retention rate, with 87% remaining at the 5-year mark.
Researchers from St Joseph’s Healthcare Hamilton Hamilton and McMaster University Hamilton Hamilton discovered that cannabis usage increased modestly over the five years after legalization but marijuana misuse declined modestly.
The researchers state, “These changes have been moderated significantly by the use of cannabis prior to the legalization. Those who consumed cannabis more frequently before the legalization had the biggest decreases for both outcomes.” Although longer-term studies are needed, the results indicate that Canadian legalization of recreational cannabis was associated both with positive and modestly negative effects among adults.
Another interesting finding was cannabis misuse notably dropped immediately after the onset of the COVID-19 pandemic – it and never returned to pre-pandemic levels.
The researchers state that “understanding environmental or psychological influences leading to such changes merits further study.”
The study also found cannabis product preferences had shifted – away from dried flower, hashish, concentrates, oil, tinctures and topicals to edibles, liquids, and vaping devices. Canada only legalized edibles and liquids a year following the legalization of oils and flower.
One of the researchers’ theories is that cannabis usage increased, while its misuse decreased. This could be due to younger users who transitioned from problematic cannabis use into non-problematic cannabis use with age.
This study was conducted to find out more about the effects of smoking on health. has been published JAMA Network Open, a new journal published by the American Medical Association.
CUD was also the subject of a recent CUD study that looked at its prevalence in pregnant women. In a study involving 893 430 pregnant women aged 12 to 55, the prevalence rate was found to be between 0.22% and 0.27% per year.