In a recent study published in JAMA Network Open, researchers investigate the association between concurrent use of tobacco and cannabis with mental health problems among teenagers in the United States.

Study: Concurrent Use of Tobacco and Cannabis and Internalizing and Externalizing Problems in US Youths. Image Credit: Rawpixel.com / Shutterstock.com

Smoking habits in young Americans

Tobacco and cannabis use is prevalent among teenagers in the United States, with 7.3% and 6.4% reporting tobacco and cannabis use in the past 30 days, respectively, according to the 2022 National Survey on Drug Use and Health (NSDUH). Concurrent use, which was reported by 5.4% of individuals, exceeds exclusive use of either substance; however, these rates do not consider the use of newer products like electronic cigarettes and vaporized cannabis.

With the rising use of these products, updated data and further research are essential to understand the impact of concurrent use on youth mental health and inform public health efforts.

About the study 

The Population Assessment of Tobacco and Health (PATH) Study is a nationally representative and longitudinal cohort study of U.S. adults and youths 12 years and older. Baseline data were collected from January 2013 to December 2014.

The PATH study included a total of 45,971 participants and an additional 7,207 ‘shadow youths’ between nine and 11 years of age. At wave four, a probability sample of 14,098 participants was added, in addition to wave six data from March to November 2021, which included 5,652 youths between 14 and 17 years of age. 

Mental health problems were assessed using a modified version of the Global Appraisal of Individual Needs-Short Screener (GAIN-SS), which measures internalizing issues like anxiety and depression as well as externalizing behaviors such as impulsivity and aggression.

Tobacco and cannabis use patterns were categorized into non-use, tobacco-only, cannabis-only, and concurrent use. Covariates included age, sex, race, parental education, and other substance use.

Ordinal logistic regressions examined associations between substance use patterns and mental health outcomes, adjusting for covariates. 

Study findings 

Among the 5,585 participants in the current study, 48.7% were female and 51.3% were male. Moreover, 27.5% of the study cohort were 14 years of age, whereas 72.5% were between 15 and 17 years of age.

Over 75% of the study participants had at least one parent who attended some college or completed higher education. About 26% of the study cohort were Hispanic, 12.7% non-Hispanic Black, 50.5% non-Hispanic White, and 11% non-Hispanic other.

About 4% of the study participants reported tobacco use, 2.5% reported cannabis use, and 3.4% reported concurrent use of both tobacco and cannabis in the past 30 days. Additionally, 9.1% reported alcohol use in the past 30 days, whereas 4.9% reported using other substances in the past 12 months.

28.4% and 24.6% of the study participants reported internalizing problems at moderate and high levels, respectively. Externalizing problems were reported at moderate and high levels by 30.7% and 32.5%, respectively.

Mental health problems were more prevalent among tobacco or cannabis users as compared to non-users. In the concurrent use group, 47.4% reported high levels of internalizing problems as compared to 44.8% in the cannabis-only group, 41.4% in the tobacco-only group, and 22.4% in the non-use group. For externalizing problems, 61.6% of concurrent users reported high levels as compared to 48.5% of cannabis-only users, 46.3% of tobacco-only users, and 30.4% of non-users.

After adjusting for covariates, the likelihood of higher internalizing problems was significantly greater for concurrent, tobacco-only, and cannabis-only users as compared to non-users with adjusted odds ratios (AORs) of 2.32, 1.95, and 2.32, respectively. No significant differences were observed in internalizing problems between concurrent and single-substance users.

The prevalence of externalizing issues was higher for concurrent, tobacco-only, and cannabis-only users as compared to non-users, with AORs of 3.10, 1.69, and 1.68, respectively. Concurrent users were almost twice as likely to report externalizing problems as compared to tobacco-only and cannabis-only users, with AORs of 1.83 and 1.85, respectively.

A greater likelihood of internalizing and externalizing problems was associated with being female, having prior 30-day alcohol use, and having past 12 months of other substance use. Younger youths at 14 years of age and those with parents with a higher education were more likely to experience externalizing problems. Non-Hispanic Black and Hispanic youths were less likely to report higher mental health problems as compared to their White peers.

Conclusions 

Concurrent use of both tobacco and cannabis was as common as tobacco-only use and more common than cannabis-only use. Notably, youths using both substances reported the highest levels of internalizing and externalizing problems. Concurrent use was also associated with a greater risk of externalizing problems than internalizing problems.

The study findings emphasize the need for integrated prevention and treatment interventions that address both substance use and mental health issues, especially given the comorbidity observed during the coronavirus disease 2019 (COVID-19) pandemic.