The Association Between Tobacco and Cannabis Use and the Age of Onset of Depression and Anxiety Symptoms: Among Adolescents and Young Adults.

INTRODUCTION: No studies have prospectively explored the association between the use of tobacco or cannabis use and the age of onset of depressive or anxiety symptoms, and no studies have identified the peak ages and ranges of onset of these symptoms among tobacco and/or cannabis users. AIMS AND METHODS: This is a secondary analysis of Texas Adolescent Tobacco and Marketing Surveillance System data, waves 9-14 (2019-20121). Participants were in 10th grade, 12th grade, and 2 years post-high school (HS) at baseline (wave 9). Interval-censoring multivariable Cox proportional hazards models were fit to assess differences in the estimated age of onset of depression and anxiety by tobacco and cannabis use while adjusting for covariates. RESULTS: We found that lifetime or ever cigarette, e-cigarette, and cannabis use had an increased risk of an earlier age of onset of depressive and anxiety symptoms across the three cohorts, and the youngest cohort was the most differentially impacted by substance use. Between ages 18 to 19 years in the 10th-grade cohort, between ages 20 to 21 years in the 12th-grade cohort, and between ages 22 to 23 years in the post-HS cohort, the estimated hazard function (or cumulative incidence) for reporting depressive and anxiety symptoms almost doubled among lifetime cigarette, e-cigarette, and cannabis users. CONCLUSIONS: Tobacco and cannabis users should be screened for mental health problems at an earlier age, especially those aged 18 years and younger, and provided with age- and culturally appropriate resources to prevent or delay the onset of anxiety and/or depression symptoms. IMPLICATIONS: The study's findings indicate that tobacco and cannabis use is directly linked to the early onset of depressive and anxiety symptoms among youth. This highlights the significance of early screening and substance use interventions, particularly for youth aged 18 years and younger, as they are disproportionately affected by both substance use and mental health problems. School-based interventions that are age- and culturally appropriate hold promise as they enable youth to seek professional help early, and in a supportive environment. Intervening early in substance shows promise in reducing the likelihood of developing mental health problems at a young age.