RESUMO
BACKGROUND AND AIMS: In 2013, Uruguay became the first country to legalize and regulate the production and distribution of cannabis for recreational use. We measured whether Uruguay's non-commercial model of recreational cannabis legalization was associated with changes in the prevalence of risky and frequent cannabis use among secondary school students. DESIGN: We used data from repeated cross-sectional surveys of secondary students in Uruguay and Chile (2007-2018). Using a difference-in-difference approach, we evaluated changes in the prevalence of past-year, past-month, any risky and frequent cannabis use following enactment (2014) and implementation (2016) of cannabis legalization among the full sample of secondary students and among students who reported past-year/month use. We examined changes separately for students ages 12 to 17, and students for whom cannabis became legally accessible, ages 18 to 21. SETTING: Uruguay and Chile (2007-2018). PARTICIPANTS: Secondary school students in 8th, 10th and 12th grade (n = 204 730). MEASUREMENTS: Past-year and past-month cannabis use; any risky cannabis use measured with the Cannabis Abuse Screening Test (CAST); and frequent cannabis use (10+ days in the past-month). FINDINGS: We found a decrease in past-year and past-month use following enactment or implementation. Among students ages 18 to 21, post-enactment, we observed a transitory increase in 2014 that decreased thereafter for: any risky use among those who reported past-year use (prevalence difference [PD] = 13.5%; 95% CI: 2.0, 24.9), frequent use in the full sample (PD = 4.5%; 95% CI: 1.0, 8.1), and frequent use among those who reported past-month use (PD = 16.8%; 95% CI: 1.9, 31.8). CONCLUSION: The legalization of recreational cannabis in Uruguay was not associated with overall increases in either past-year/past-month cannabis use or with multi-year changes in any risky and frequent cannabis use among young people.
Assuntos
Cannabis , Adolescente , Adulto , Criança , Estudos Transversais , Humanos , Legislação de Medicamentos , Instituições Acadêmicas , Estudantes , Adulto JovemRESUMO
BACKGROUND: In 2013, Uruguay became the first country in the world to legalize recreational cannabis, instituting a non-commercial state regulatory model of production and supply. This study provides the first empirical evidence on its impacts on adolescent use of cannabis and related risks. METHODS: We use a generalization of the synthetic control method (SCM) to estimate the impact of legalization in Uruguay on adolescent past year and month cannabis use, perceived availability of cannabis and perceived risk of cannabis use. We compare biennial high school student self-reported survey data from Montevideo and regions in the interior of Uruguay post-legalization (2014-2018) and post initial implementation (2015-2018) to a synthetic counterfactual constructed using a weighted combination of 15 control regions in Chile. RESULTS: We find no evidence of an impact on cannabis use or the perceived risk of use. We find an increase in student perception of cannabis availability (58% observed vs. 51% synthetic control) following legalization. CONCLUSION: Our findings provide some support for the thesis that Uruguay's state regulatory approach to cannabis supply may minimize the impact of legalization on adolescent cannabis use. At the same time, our study period represents a period of transition: pharmacy access, by far the most popular means of access, was not available until the summer of 2017. Additional study will be important to assess the longer-term impacts of the fully implemented legalization regime on substance use outcomes.
Assuntos
Cannabis , Fumar Maconha , Adolescente , Humanos , Legislação de Medicamentos , Fumar Maconha/epidemiologia , Estudantes , Uruguai/epidemiologiaRESUMO
AIMS: Amid changing marijuana policies in the Southern Cone, we examined relationships between marijuana-related risk factors and marijuana use among adolescents in Argentina, Chile, and Uruguay from 2001 to 2016. METHODS: Using cross-sectional surveys from 8th, 10th, and 12th graders and weighted time-varying effect models, we estimated associations between perceived risk (no/low risk versus moderate/great risk) and perceived availability (easy/very easy versus difficult/very difficult/not able to obtain) of marijuana, and any past-month marijuana use. RESULTS: In all countries, marijuana use increased over time and adolescents who perceived no/low risk and easy availability had higher odds of use. In Argentina, the bivariate risk/use association weakened from 2001 (ORâ¯=â¯15.24, 95%CIâ¯=â¯9.63, 24.12) to 2004 [ORâ¯=â¯3.86 (2.72, 5.48)] and strengthened until 2011 [ORâ¯=â¯8.22 (7.56, 10.30)]; the availability/use association strengthened from 2005 [ORâ¯=â¯5.32 (4.05, 6.98)] to 2009 [ORâ¯=â¯20.77 (15.57, 27.70)] and weakened until 2014 [ORâ¯=â¯11.00 (9.11, 13.27)]. In Chile, the risk/use association weakened from 2001 [ORâ¯=â¯7.22 (6.57, 7.95)] to 2015 [ORâ¯=â¯5.58 (4.82, 6.48)]; the availability/use association weakened from 2001 [ORâ¯=â¯5.92 (4.96, 7.06)] to 2015 [ORâ¯=â¯4.10 (3.15, 5.34)]. In Uruguay, the risk/use association weakened from 2003 [ORâ¯=â¯34.22 (22.76, 51.46)] to 2016 [ORâ¯=â¯6.23 (4.96, 7.83)]; the availability/use association weakened from 2005 [ORâ¯=â¯29.13 (13.39, 63.39) to 2007 [ORâ¯=â¯9.42 (3.85, 23.07)], and strengthened until 2016 [ORâ¯=â¯22.68 (12.03, 42.76)]. CONCLUSIONS: Overall, the association between risk and use weakened in all countries, suggesting risk perceptions became a weaker determinant of marijuana use. Perceived availability remained strongly associated with use and may become an increasingly important driver of use (particularly in Uruguay and Argentina).