Columbia University Irving Medical Center Jun 19 2025 Addictive use of social media, video games, or mobile phones-but not total screen time-is associated with worse mental health among preteens, a new study by researchers at Columbia and Cornell universities has found.  The study, published June 18 in JAMA , examined the social media use of nearly 4,300 children, starting at age 8, and how use changed over the next four years.  Addictive use of screens-excessive use that interfered with