Canadian researchers have delved into changes into cannabis use and misuse in the five years following recreational legalization, compared to pre-legalization.
The study included data from 1428 adults who participated in up to 11 biannual assessments from September 2018 to October 2023 in Ontario, with the data analyzed between November 2023 to January 2024. Use frequency and misuse were assessed using the 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.
What the researchers from St Joseph’s Healthcare Hamilton and McMaster University Hamilton found was cannabis use frequency increased modestly in the 5 years following legalization, but cannabis misuse decreased modestly.
“These changes were substantially moderated by prelegalization cannabis use, with more frequent consumers of cannabis before legalization exhibiting the largest decreases in both outcomes,” state the researchers. “Although longer-term surveillance is required, these results suggest Canadian recreational cannabis legalization was associated with modest negative and positive consequences 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.
“Understanding the environmental or psychological factors leading to these changes warrants further investigation,” state the researchers.
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. Edibles and liquids only became legal in Canada a year after flower and oils were legalized.
The researchers suggest one of the reasons cannabis use increased while misuse decreased could be younger cannabis users, who typically transition from problematic to non-problematic use as they get older.
The study has been published in the journal JAMA Network Open.
Another recently published CUD related study was in relation to its prevalence rate among pregnant women. The research, involving 893,430 pregnant women aged 12-55, found yearly prevalence to range from 0.22% (2015) to 0.27% (2018 and 2019).
