E-cigarettes in college: Associations between mental health and e-cigarette use with other substances.

Introduction: College students are a priority population for substance use prevention, and other studies have reported associations between mental health and e-cigarette use. This study described the association of mental health to e-cigarette and other substance use (ECIG+ use) among US college students.

Methods: We used Fall 2018 and Spring 2019 National College Health Assessment data among undergraduate students aged 18-24 years (n=55654) at 138 institutions. We characterized substance use patterns and used multinomial regression to model adjusted odds of past 30-day ECIG use type [no substance use (reference); sole e-cigarette use; e-cigarette use and other substance use (ECIG+ use); no e-cigarette use but other substance use] by mental health characteristics, past 12-month diagnosis/treatment and psychological distress, individual characteristics, and college characteristics.

Results: Alcohol was the most prevalent substance (58%) used, followed by cannabis (23%) and e-cigarettes (15%). Nearly all (95%) students who used e-cigarettes reported using another substance. Adjusted odds of ECIG+ use (vs no substance use) were higher among students with past 12-month mental health diagnosis/treatment (AOR=1.5; 95% CI: 1.4-1.6) and higher psychological distress (AOR=1.1; 95% CI: 1.1-1.2). Other characteristics significantly associated with ECIG+ use included gender identity, sexual orientation, race and ethnicity, self-rated health, year in school, cumulative grade average, fraternity/sorority membership, and current residence.

Conclusions: Most students who used e-cigarettes also reported other substance use, and this pattern of use was associated with poorer mental health outcomes than no substance use. Clarifying the relationship between mental health and ECIG+ use may enhance health interventions for college students.