Trends in Single, Dual, and Poly Use of Alcohol, Cigarettes, and Marijuana Among US High-School Students: 1991–2017

Objectives. To evaluate trends in patterns (single, dual, or poly) of current use of alcohol, cigarettes, and marijuana (ACM) among youths in the United States. Methods. I used data from the 1991-2017 Youth Risk Behavior Surveys (n = 203 663) to report average annual percentage change (AAPC) and linear trends of single, dual, and poly use of ACM among youths. Results. From 1991 to 2017, the prevalence of marijuana-only use increased from 0.6% to...