More teens who vape are using addictive or mind-altering substances than previously believed, according to a new study in the American Journal of Preventive Medicine, published by Elsevier. [...] "Our study provided a more nuanced view of youth e-cigarette use behaviors than earlier studies. We found that youth were more likely to report vaping nicotine and marijuana than 'just flavoring' only, and that cigarette smoking intensity was associated with an increasing proportion of students reporting vaping nicotine only," explained co-investigator Hongying Dai, [...]