The Effects of Cannabis Use on the Development of Adolescents and Young Adults

This review summarizes evidence on the effects of cannabis use on the development of adolescents and young adults. It draws on epidemiological studies, neuroimaging studies, case-control studies, and twin and Mendelian randomization studies. The acute risks include psychiatric symptoms associated with the use of high THC (tetrahydrocannabinol) products and motor vehicle accidents. Daily cannabis use during adolescence is associated with cannabis dependence and poor cognitive function, which may affect educational attainment and occupational choice. Daily use of highly potent cannabis is associated with more severe psychological symptoms, such as psychoses, mania, and suicidality. There are more mixed findings on depressive symptoms, anxiety, and violence and debates about the interpretation of these associations. Legalization of adult cannabis use may increase cannabis use and dependence among adolescents and young adults. The regulation of cannabis after legalization needs to minimize adolescent uptake and cannabis-related adverse developmental outcomes.