Shared Environmental Influences on Electronic Cigarette Use Among Adolescent and Young Adult Females

Introduction: Electronic cigarettes are now the most commonly used form of tobacco product among youth in the United States. Current evidence suggests that although e-cigarettes are perceived as less harmful and preferred over combustible cigarettes by adolescents, adolescents who try e-cigarettes are at greater risk of transitioning to combustible cigarettes. The genetic and environmental contributions to liability for e-cigarette use have not yet been examined using a behavioral genetic design. Methods: Behavioral genetic models of lifetime and current e-cigarette use and friends who use e-cigarettes were examined among female monozygotic and dizygotic twins. Results: A total of 41 female twin pairs (65.9% monozygotic twins; age = 19.7, SD = 1.6) with complete data on the study variables were included in the present analyses.The majority of the sample (68.1%) had at least some friends who use e-cigarettes. Additive genetic effects on e-cigarette use were not present, but the shared environment explained 98.7% of the variance in lifetime e-cigarette use, 96.6% in current e-cigarette use, and 94.9% in affiliation with friends who use e-cigarettes. Conclusion: This first study on the behavioral genetics of e-cigarette use among adolescents and young adults suggest that environmental factors shared by twins within a family seem to play a predominant role in the initial stages of e-cigarette use, a finding that is consistent with what has been found for tobacco. The findings emphasize the importance of continuing population-based tobacco control interventions to reduce the burden of e-cigarette use among adolescents.