This study published in in suggests that such frequent use of digital media by adolescents might increase their odds of developing symptoms of attention deficit hyperactivity disorder. In this longitudinal cohort survey study of adolescents aged 15 and 16 years at baseline and without symptoms of ADHD, there was a significant association between higher frequency of modern digital media use and subsequent symptoms of ADHD over a 24-month follow-up.
Ra, C. K., Cho, J., Stone M. D., De La Cerda, J., Goldenson, N. I., Moroney, E., Tung, I., Lee, S. S., & Leventhal, A. M. (2018). Association of digital media use with subsequent symptoms of Attention-Deficit/Hyperactivity Disorder among adolescents. JAMA, 320(3), 255–263. https://dx.doi.org/10.1001/jama.2018.8931