It's a familiar lament: teenagers are spending all their time on digital devices, and it's wreaking havoc on their physical and mental health. But a study published in January in Psychological Science suggests a moderate level of use is not necessarily harmful—and may even be beneficial. The effect on well-being varies depending the type of medium or device: TV and movies, video games, computers and smartphones, as well as the day of the week (weekday versus weekend). The optimal amount of exposure peaks at around one to two hours daily during the week and longer on weekends. Limiting your teen's screen time is fine, but consider the benefits before you pull the plug entirely.

Source: “A Large-Scale Test of the Goldilocks Hypothesis: Quantifying the Relations Between Digital-Screen Use and the Mental Well-Being of Adolescents,” by Andrew K. Przybylski and Netta Weinstein, in Psychological Science, Vol. 28, No. 2; January 13, 2017