The great decline in adolescent cigarette smoking since 2000: consequences for drug use among US adolescents.

OBJECTIVE: Adolescent cigarette smoking declined steadily and substantially from 2000 to 2018. This paper considers the potential consequences of this 'great decline' for the prevalence of other drug use among adolescents.
METHODS: Data are annual, cross-sectional, nationally representative Monitoring the Future surveys of more than 1.2 million US students in 12th, 10th and 8th grades from 2000 to 2018. Analyses include trends in the past 12 months' non-medical amphetamine, tranquillisers and opioid use overall, among ever and never cigarette smokers, and projected if adolescent cigarette smoking levels had remained at 2000 levels.
RESULTS: Within groups of ever and never cigarette smokers, the prevalence for each of the three substances has either changed little or overall increased in 2018 as compared with 2000. When the two groups were combined into one pool, the overall prevalence for each of the drugs declined by about half. The decline resulted from the growing group of never smokers, whose levels of non-medical drug use over the study period were at least four times lower than the levels of ever smokers.
CONCLUSIONS: The results support the 'gateway' prediction that declines in cigarette smoking among adolescents pull downward their non-medical use of amphetamines, tranquillisers and opioids. Continuing to reduce adolescent smoking through policy and programmatic prevention efforts should have further positive spillover effects on adolescent drug use. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.