Tobacco-Cannabis Co-use and Risk of Substance Use Problems Among Black and Hispanic Adolescent and Young Adult Females in New York City

Tobacco-cannabis co-use is more common than exclusive cannabis use and is linked to more severe tobacco and cannabis health consequences. We assessed trends and predictors of tobacco-cannabis co-use and their link to future substance use problems and severity among Black and Hispanic adolescent and young adult (AYA) females living in New York City. Secondary data were analyzed from a 7-year (2013–2020) prospective open cohort study conducted at Mount Sinai Adolescent Health Center in New York City (n = 1281). Participants completed questionnaires every 6 months, and self-reported information on use of smoked tobacco, cannabis, and blunts/spliffs; sexual risk behaviors; depressive symptoms; and other substance use. Regression analyses examined initiation and frequency of past 30-day co-use and risk of future substance use severity. Age-adjusted prevalence of past 30-day cannabis use increased from 46.5% in 2013–2014 to 59.0% in 2019–2020, while past 30-day tobacco smoking declined from 22.1 to 6.1%. After accounting for blunt/spliff use, any use of tobacco increased from 31.6% in 2013–2014 to 39.6% in 2019–2020. Co-consumers were more likely to meet criteria for clinical depression (OR = 1.34, 95% CI 1.12–1.61) and have same-sex (OR = 1.35, 95% CI 1.03–1.76) and/or multiple male sex partners (OR = 1.45, 95% CI 1.23–1.71). Those who used blunts/spliffs frequently or rarely had higher risk profiles for problematic substance use. Tobacco-cannabis co-use, particularly blunt use, appears to drive increasing prevalence of cannabis use, sustain overall rates of tobacco use, and predicts substance use problems among inner-city Black and Hispanic AYA females, independent of other factors.