Northern Medical Program, University of Northern British Columbia, Prince George, Canada.
Human Brain Laboratory, Centre for Addiction and Mental Health (CAMH), Toronto, Canada.
Addiction. 2021 Dec;116(12):3454-3462. doi: 10.1111/add.15535. Epub 2021 Jun 4.
Canada's 2018 Cannabis Act allows youth (age 12-17 years) to possess up to 5 g of dried cannabis (or equivalent) for personal consumption/sharing. This study assessed whether the Cannabis Act was associated with changes in police-reported cannabis offences among youth in Canada.
Time series model using national daily criminal incident data from January 1, 2015-December 31, 2018 from the Canadian Uniform Crime Reporting Survey (UCR-2). Seasonal autoregressive integrated moving average time series models, stratified by sex, assessed the relations between legalization and youth cannabis-related offences.
Canada, 2015-2018.
Police-reported cannabis-related offenses among youth age 12-17 years (male, n = 32 178; female, n = 9001).
Outcomes: police-reported cannabis-related crimes, property crimes, and violent crimes. Covariate: calendar-month.
For females, legalization was associated with a step-effect decrease of 4.56 (95% confidence interval [CI] = 3.32, 5.81; P < 0.001) police-reported cannabis-related criminal offences per day, an effect equivalent to a 64.6% (standard error [SE] = 33.5%) reduction. For males, legalization was associated with a drop of 12.73 (95% CI = 8.82, 16.64; P < 0.001) cannabis-related offences per day, equaling a decrease of 57.7% (SE = 22.6%). Results were inconclusive as to whether there were associations between cannabis legalization and patterns of property crimes or violent crimes.
Implementation of the Cannabis Act in Canada in 2018 appears to have been associated with decreases of 55%-65% in cannabis-related crimes among male and female youth.
加拿大 2018 年《大麻法》允许 12-17 岁的青少年（年龄）拥有最多 5 克干大麻（或同等物）用于个人消费/分享。本研究评估了《大麻法》是否与加拿大青少年的警察报告大麻犯罪的变化有关。
使用加拿大统一犯罪报告调查（UCR-2）2015 年 1 月 1 日至 2018 年 12 月 31 日的全国每日犯罪事件数据，采用时间序列模型。按性别分层的季节性自回归综合移动平均时间序列模型评估了合法化与青少年大麻相关犯罪之间的关系。
加拿大，2015-2018 年。
12-17 岁青少年（男性，n=32178；女性，n=9001）的警察报告大麻相关犯罪。
结果：警察报告的大麻相关犯罪、财产犯罪和暴力犯罪。协变量：日历月。
对于女性，合法化与每天报告的大麻相关犯罪减少 4.56（95%置信区间[CI]为 3.32，5.81；P<0.001）有关，这一效应相当于减少 64.6%（标准误差[SE]为 33.5%）。对于男性，合法化与每天 12.73 次大麻相关犯罪下降有关（95%CI=8.82，16.64；P<0.001），相当于减少 57.7%（SE=22.6%）。关于大麻合法化与财产犯罪或暴力犯罪模式之间是否存在关联的结果尚无定论。
加拿大 2018 年《大麻法》的实施似乎与男性和女性青少年大麻相关犯罪减少 55%-65%有关。
