Concurrent use of cannabis and tobacco linked to externalizing disorders in youth

Researchers have found that concurrent use of tobacco and cannabis was associated with higher levels of externalizing problems compared to use of only one of the substances for youths aged 14 to 17 years, but that there was no association with higher levels of internalizing problems. Externalizing problems include hyperactivity, impulsivity, aggression, and conduct disorders, while internalizing problems are characterized by anxiety abnd depression, and social withdrawal. The study results suggested that there should be integrated treatment for mental health, tobacco, and cannabis use for youth. For the study, the researchers analyzed wave 6 data within the Population Assessment of Tobacco and Health (PATH) Study, with data collected from March to November, 2021. The cohort is US youths aged 14–17 years. The researchers divided past 30 day use of any tobacco and cannabis products into four categories: concurrent, tobacco only, cannabis only, and non‐use. Mental health problems (internalizing and externalizing) were measured by self‐report using the Global Appraisal of Individual Needs–Short Screener and separately categorized into 3 levels: low (0–1 symptoms), moderate (2–3 symptoms), and high (4 or more symptoms). A total of 5,585 youths were included, half male and half female. The prevalence of concurrent use was 3.4%, and comparable to tobacco‐only use (3.9%) but greater than cannabis‐only use (2.9%). There were high levels of internalizing and externalizing problems for the concurrent use group (47.4% internalizing, 61.6% externalizing), followed by the cannabis‐only group (44.8% internalizing, 48.5% externalizing), the tobacco‐only group (41.4% internalizing, 46.3% externalizing), and the non‐use group (22.4% internalizing, 30.4% externalizing). After controlling for covariates, only concurrent tobacco and cannabis use was associated with higher levels of externalizing problems than cannabis‐only or tobacco‐only use. There were no associations of internalizing problems with concurrent use compared to use of cannabis or tobacco alone. The study, Concurrent Use of Tobacco and Cannabis and Internalizing and Externalizing Problems in US Youths, is published in the July 1 issue of JAMA Network Open .