Historique
Article de Périodique
Does liberalisation of cannabis policy influence levels of use in adolescents and young adults? A systematic review and meta-analysis (2019)
Auteur(s) :
MELCHIOR, M. ;
NAKAMURA, A. ;
BOLZE, C. ;
HAUSFATER, F. ;
EL KHOURY, F. ;
MARY-KRAUSE, M. ;
AZEVEDO DA SILVA, M.
Année
2019
Page(s) :
e025880
Sous-type de document :
Méta-analyse / Meta-analysis ; Revue de la littérature / Literature review
Langue(s) :
Anglais
Refs biblio. :
73
Domaine :
Drogues illicites / Illicit drugs
Discipline :
EPI (Epidémiologie / Epidemiology)
Thésaurus mots-clés
CANNABIS
;
LIBERALISATION
;
LEGALISATION
;
ADOLESCENT
;
JEUNE ADULTE
;
POLITIQUE
;
TYPE D'USAGE
;
USAGE RECREATIF
;
EVOLUTION
;
DECRIMINALISATION
Résumé :
Objectives: To examine the effect of cannabis policy liberalisation (decriminalisation and legalisation) levels of use in adolescents and young adults.
Design: Systematic review and meta-analysis.
Inclusion criteria: Included studies were conducted among individuals younger than 25 years and quantitatively assessing consequences of cannabis policy change. We excluded articles: (A) exclusively based on participants older than 25 years; (B) only reporting changes in perceptions of cannabis use; (C) not including at least two measures of cannabis use; (D) not including quantitative data; and (E) reviews, letters, opinions and policy papers. PubMed, PsycINFO, Embase and Web of Science were searched through 1 March 2018.
Data extraction and synthesis: Two independent readers reviewed the eligibility of titles and abstracts and read eligible articles, and four authors assessed the risk of bias (Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies). Extracted data were meta-analysed. The protocol was registered with PROSPERO.
Results: 3438 records were identified via search terms and four via citation lists; 2312 were retained after removal of duplicates, 99 were assessed for eligibility and 41 were included in our systematic review. 13 articles examined cannabis decriminalisation, 20 examined legalisation for medical purposes and 8 examined legalisation for recreational purposes. Findings regarding the consequences of cannabis decriminalisation or legalisation for medical purposes were too heterogeneous to be meta-analysed. Our systematic review and meta-analysis suggest a small increase in cannabis use among adolescents and young adults following legalisation of cannabis for recreational purposes (standardised mean difference of 0.03, 95% CI -0.01 to -0.07). Nevertheless, studies characterised by a very low/low risk of bias showed no evidence of changes in cannabis use following policy modifications.
Conclusions: Cannabis policy liberalisation does not appear to result in significant changes in youths' use, with the possible exception of legalisation for recreational purposes that requires monitoring.
Trial registration number CRD42018083950.
Design: Systematic review and meta-analysis.
Inclusion criteria: Included studies were conducted among individuals younger than 25 years and quantitatively assessing consequences of cannabis policy change. We excluded articles: (A) exclusively based on participants older than 25 years; (B) only reporting changes in perceptions of cannabis use; (C) not including at least two measures of cannabis use; (D) not including quantitative data; and (E) reviews, letters, opinions and policy papers. PubMed, PsycINFO, Embase and Web of Science were searched through 1 March 2018.
Data extraction and synthesis: Two independent readers reviewed the eligibility of titles and abstracts and read eligible articles, and four authors assessed the risk of bias (Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies). Extracted data were meta-analysed. The protocol was registered with PROSPERO.
Results: 3438 records were identified via search terms and four via citation lists; 2312 were retained after removal of duplicates, 99 were assessed for eligibility and 41 were included in our systematic review. 13 articles examined cannabis decriminalisation, 20 examined legalisation for medical purposes and 8 examined legalisation for recreational purposes. Findings regarding the consequences of cannabis decriminalisation or legalisation for medical purposes were too heterogeneous to be meta-analysed. Our systematic review and meta-analysis suggest a small increase in cannabis use among adolescents and young adults following legalisation of cannabis for recreational purposes (standardised mean difference of 0.03, 95% CI -0.01 to -0.07). Nevertheless, studies characterised by a very low/low risk of bias showed no evidence of changes in cannabis use following policy modifications.
Conclusions: Cannabis policy liberalisation does not appear to result in significant changes in youths' use, with the possible exception of legalisation for recreational purposes that requires monitoring.
Trial registration number CRD42018083950.
Affiliation :
Department of Social Epidemiology, INSERM UMRS 1136 IPLESP, Paris, France