Abstract
Objectives: Little is known about the association between specific types of screen time and adolescents' substance use. Thus, this study aimed to investigate the associations between screen time for studying, working, watching movies, playing games, and using social media and frequency of alcohol and tobacco use. Methods: In this cross-sectional study, Brazilian adolescents answered survey questions related to frequency of tobacco and alcohol consumption, and reported their daily volume of five types of screen time. Multilevel ordered logistic regression models were performed. Results: Each 1-hour increase in ST for studying was associated with 26% lower odds of smoking (OR = 0.74; 95% CI: 0.61-0.90) and 17% lower odds of drinking alcohol (OR = 0.83; 95% CI: 0.76-0.91) in the past 30 days. The increase of 1 hour of social media use was associated with 10% greater odds of smoking (OR = 1.10; 95% CI: 1.02-1.18) and a 13% greater chance of consuming alcohol (OR = 1.13; 95% CI: 1.08-1.18) in the past 30 days. Conclusion: The association between screen time and substance use appears to be type-specific. Future longitudinal research is needed to explore causal relationships.