McGrath Daniel S, Williams Robert J, Allami Youssef, Christensen Darren R, Hodgins David C, Nicoll Fiona, Shaw Carrie A, Stevens Rhys M G
Department of Psychology, University of Calgary.
Faculty of Health Sciences, University of Lethbridge.
Cannabis. 2024 Dec 12;7(3):14-29. doi: 10.26828/cannabis/2024/000247. eCollection 2024.
In October 2018, the Government of Canada legalized cannabis for recreational use nationwide. The effects of legalization on cannabis use have been primarily assessed through cross-sectional surveys.
In the present study, a two-wave longitudinal design was used to explore potential demographic, substance use and behavioral addiction, and mental health predictors of change in cannabis use status following legalization. Canadian online panelists (18+) were initially surveyed about their gambling and substance use in 2018 (i.e., before cannabis legalization). From the original sample, 4,707 (46.2%) were retained in the follow-up survey one year later, post-cannabis legalization. These respondents were the focus of the present study.
When queried about how legalization would impact their use, 61.8% said, 'I'll never use it', 21.1% stated "I'll use it about the same as I do now," 10.3% indicated, "I may try it for the first time," 5.0% answered, "I'll use it more," and 1.9% responded that, "I'll use it less." Consistent with these sentiments, within the retained sample there was a modest but significant increase in cannabis use from baseline (18.4%) to follow-up (26.1%). Regressions established that younger age, being male, substance use, tobacco or e-cigarette use, problematic gambling, and stated intention to use cannabis were predictors of later cannabis use.
This national cohort design indicates that cannabis use appears to have increased in Canada following legalization. The present study makes a unique contribution by also identifying variables that statistically forecast movement toward and away from cannabis use.
2018年10月，加拿大政府将娱乐用大麻在全国范围内合法化。大麻合法化对大麻使用的影响主要通过横断面调查进行评估。
在本研究中，采用两波纵向设计，以探讨大麻合法化后大麻使用状况变化的潜在人口统计学、物质使用和行为成瘾以及心理健康预测因素。2018年（即大麻合法化之前），对加拿大在线小组成员（18岁及以上）进行了关于他们赌博和物质使用情况的初步调查。在最初的样本中，4707人（46.2%）在大麻合法化一年后的后续调查中被保留下来。这些受访者是本研究的重点。
当被问及合法化将如何影响他们的使用时，61.8%的人说“我永远不会使用”，21.1%的人表示“我会和现在使用的频率差不多”，10.3%的人指出“我可能会第一次尝试”，5.0%的人回答“我会使用得更多”，1.9%的人回答“我会使用得更少”。与这些观点一致，在保留的样本中，大麻使用从基线（18.4%）到随访（26.1%）有适度但显著的增加。回归分析表明，年龄较小、男性、物质使用、烟草或电子烟使用、问题赌博以及表示有使用大麻的意图是后期使用大麻的预测因素。
这项全国队列设计表明，加拿大在大麻合法化后，大麻使用似乎有所增加。本研究还通过识别在统计学上预测大麻使用增减趋势的变量做出了独特贡献。
