This report by the Children's Commissioner (England) shows the two sides of social media. While it reports a positive impact on 8- to 12-year-olds and their well-being, it also warns that young people are becoming dependent on social validation offered by social media platforms. This leads to anxiety and attempts to adapt offline behaviours to idealized online profiles.
See also: What Makes Teens Unhappy? Their Phones (January 2018 issue of Youth Development Today)