A sudden increase in the rates of depression, anxiety and self-harm was seen in adolescents — particularly girls — in the United States and the United Kingdom around 2012 or 2013 (see go.nature.com/2up38hw). Only one suspect was in the right place at the right time to account for this sudden change: social media. Its use by teenagers increased most quickly between 2009 and 2011, by which point two-thirds of 15–17-year-olds were using it on a daily basis1. Some researchers defend social media, arguing that there is only circumstantial evidence for its role in mental-health problems2,3. And, indeed, several studies2,3 show that there is only a small correlation between time spent on screens and bad mental-health outcomes. However, I present three arguments against this defence.
Social media as if it were sugar: safe in small to moderate quantities, and harmful only if teenagers consume large quantities.
