Russell C Callaghan1,2,3, Julia Vander Heiden1,3, Marcos Sanches4, Mark Asbridge5, Andrew Hathaway6, Stephen J Kish2. 1. Northern Medical Program, University of Northern British Columbia, Prince George, Canada. 2. Human Brain Laboratory, Centre for Addiction and Mental Health (CAMH), Toronto, Canada. 3. Canadian Institute for Substance Use Research (CISUR), University of Victoria, Victoria, Canada. 4. Krembil Centre for Neuroinformatics, Centre for Addiction and Mental Health (CAMH), Toronto, Canada. 5. Department of Community Health and Epidemiology, Dalhousie University, Halifax, Canada. 6. College of Social and Applied Human Sciences, University of Guelph, Guelph, Canada.
Abstract
AIMS: 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. DESIGN: 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. SETTING: Canada, 2015-2018. CASES: Police-reported cannabis-related offenses among youth age 12-17 years (male, n = 32 178; female, n = 9001). MEASUREMENTS: Outcomes: police-reported cannabis-related crimes, property crimes, and violent crimes. Covariate: calendar-month. FINDINGS: 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. CONCLUSIONS: 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.
AIMS: 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. DESIGN: 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. SETTING: Canada, 2015-2018. CASES: Police-reported cannabis-related offenses among youth age 12-17 years (male, n = 32 178; female, n = 9001). MEASUREMENTS: Outcomes: police-reported cannabis-related crimes, property crimes, and violent crimes. Covariate: calendar-month. FINDINGS: 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. CONCLUSIONS: 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.
Authors: Russell C Callaghan; Marcos Sanches; Robin M Murray; Sarah Konefal; Bridget Maloney-Hall; Stephen J Kish Journal: Can J Psychiatry Date: 2022-01-12 Impact factor: 5.321
Authors: Dafna Sara Rubin-Kahana; Jean-François Crépault; Justin Matheson; Bernard Le Foll Journal: Front Psychiatry Date: 2022-09-23 Impact factor: 5.435