Vallone DM, et al. - Researchers sought to calculate the prevalence, patterns, and factors associated over time with e-cigarette use among adolescents and younger adults in the United States. They included two nationally representative longitudinal samples of adolescents and younger adults aged 15 to 34 years from the Truth Longitudinal Cohort, a national, probability-based cohort. In this cohort, they recruited individuals through address-based sampling, and subsamples were recruited from a probability-based online panel. They recruited a sum of 14,379 individuals (mean [SD] age, 24.3 [0.09] years; 8142 female [51.0%]) were included in wave 7 and 12,114 (mean [SD] age, 24.5 [0.10] years; 6,835 female [50.1%]) in wave 8. The results suggested that the e-cigarette device JUUL seems to be correlated with the youth e-cigarette epidemic, bringing new users and promoting frequent use with their highly addictive nicotine content and appealing flavors. The conclusions of this research emphasize the critical requirement for improved e-cigarette product regulation at the federal, state, and local levels.