Genome-wide association meta-analysis of age at first cannabis use

Cannabis is one of the most commonly used substances among adolescents and young adults. Earlier age at cannabis initiation is linked to adverse life outcomes, including multi-substance use and dependence. This study estimated the heritability of age at first cannabis use and identified associations with genetic variants.A twin-based heritability analysis using 8055 twins from three cohorts was performed. We then carried out a genome-wide...