Young-adult compared to adolescent onset of regular cannabis use: A 20-year prospective cohort study of later consequences

This study followed nearly 1800 adolescents and young adults from age 15 to 35. Of that group, those who began using cannabis as adolescents were 20 times more likely to be illicit drug users, 3.7 times more likely to be high-risk alcohol drinkers, and 7.2 times more likely to be daily cigarette smokers than minimal or non-cannabis users. In this study, cannabis users who began regular use in their teens had poorer later life outcomes than non-using peers. These findings support the concern that youth and young adult onset of regular cannabis use impairs reaching full potential in adulthood. With the emergence of higher THC concentration products since this study was initiated over 20 years ago, the later harms of beginning regular cannabis use in youth and young adulthood will likely further increase.

By Gary C K Chan, Denise Becker, Peter Butterworth, Lindsey Hines, Carolyn Coffey, Wayne Hall, George Patton

Read the full study at the National Library of Medicine.