Historical trends in the grade of onset and sequence of cigarette, alcohol, and marijuana use among adolescents from 1976-2016: Implications for "Gateway" patterns in adolescence.

ABSTRACT: INTRODUCTION:In the past decade, marijuana use prevalence among adolescents has remained relatively steady while cigarette and alcohol prevalence has declined. We examined historical trends in: average grade of onset of marijuana, alcohol, and cigarette use by 12th grade; proportion who try alcohol/cigarettes before first marijuana use, among those who use by 12th grade; and conditional probability of marijuana use by 12th grade after trying alcohol/cigarettes. METHODS:Data were drawn from 40 yearly, cross-sectional surveys of 12th grade US adolescents. A subset of students (N?=?246,050) were asked when they first used each substance. We reconstructed cohorts of substance use from grade-of-onset to determine sequence of drug use, as well as probability of marijuana use in the same or later grade. RESULTS:Average grade of first alcohol and cigarette use by 12th grade increased across time; e.g., first cigarette increased from grade 7.9 in 1986 to 9.0 by 2016 (?=0.04, SE?=?0.001, p?

SUBMITTER: Keyes KM 

PROVIDER: S-EPMC6390293 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature