Adolescent Cannabis Users Who Have Never Smoked A Combustible Cigarette: Trends and Level of Addictive Drug Use from 1976 to 2020.

Background: Adolescents cannabis users are at a substantially elevated risk for use of highly addictive drugs such as cocaine, heroin, and nonmedical use of prescription drugs. Unknown is whether this elevated risk applies to adolescent cannabis users who have never smoked a combustible cigarette, a group that has grown considerably in size in recent years. This study documents the recent growth in the proportion of adolescent cannabis users who abstain from combustible cigarette use, and examines their probability for use of addictive drugs.

Methods: Data are annual, cross-sectional, nationally-representative Monitoring the Future surveys of 607,932 U.S. 12^th grade students from 1976-2020.

Results: Among ever cannabis users, the percentage who had never smoked a combustible cigarette grew from 11% in 2000 to 58% in 2020. This group had levels of addictive drug use that were 8% higher than their peers. In comparison, adolescents who had ever used cannabis - regardless of whether they had ever smoked a cigarette - had levels of addictive drug use 500% higher than their peers.

Conclusions: Adolescent cannabis users who have not smoked a combustible cigarette have much lower levels of addictive drug use than the group of cannabis users as a whole. These results suggest policies and laws aimed at reducing adolescent prevalence of addictive drugs may do better to focus on cigarette use of adolescent cannabis users rather than cannabis use per se.