The mediating roles of mental health problems and racial differences in the linkage between social media use and E-cigarette use among American youth

Objective: Social media use is shown to be linked to youth's e-cigarette use. However, less is known about the underlying mechanisms. This study examined the mediating roles of internalizing and externalizing problems in the association between youth's social media use and e-cigarette use, and the racial differences in the mediation association. Methods: The study sample included 4913 U.S. youth from the Population Assessment of Tobacco and Health Study Waves 3-5 (2015-2019). Two weighted generalized structural equation models were conducted to examine the mediation pathways between youth's social media use (Wave 3) and past-30-day e-cigarette use (Wave 5) through internalizing and externalizing problems (Wave 4), respectively. Invariance tests were conducted to examine racial group differences. Results: Youth with high social media use frequency were more likely to use e-cigarettes (total effect: OR = 1.20, p < 0.001 in both internalizing and externalizing models). Internalizing and externalizing problems mediated the aforementioned associations (mediation proportions: 5.05% and 5.66%, respectively). The invariance tests indicated a significant difference between White and non-White groups (both ps < 0.001), where a larger proportion of mediation was found in the non-White group (12.22% for internalizing and 11.99% for externalizing) compared to their White counterparts (2.46% for internalizing and 3.17% for externalizing). Conclusions: Mental health problems following social media use served as a risk factor for e-cigarette use among youth. Interventions aiming to improve youth's mental health could in turn temper e-cigarette use among youth social media users, and implementing tailored interventions in response to racial differences is warranted.