Facebook-owned Instagram has been criticised for keeping secret its internal research into the effect social media had on teenager users.
Campaign groups and MPs have said it is proof the company puts profit first, reports BBC.
Instagram said the research showed its "commitment to understanding complex and difficult issues".
The Wall Street Journal's report, not disputed by Facebook, finds:
A 2019 presentation slide said: "We make body-image issues worse for one in three teenage girls"
Another slide said teenagers blamed Instagram for increased levels of anxiety and depression