Though "correlation vs causation" should be noted here. It may just be that people that are already depressed use Facebook more, instead of Facebook actually making you depressed.
> Lead author Lui yi Lin, B.A., who will be graduating from the University of Pittsburgh School of Medicine this spring, emphasized that, because this was a cross-sectional study, it does not disentangle cause and effect.
> βIt may be that people who already are depressed are turning to social media to fill a void,β she said.
Yes. Not just social anxiety, but down right depression.
Source: Research Links Heavy Facebook And Social Media Usage To Depression => https://www.forbes.com/sites/amitchowdhry/2016/04/30/study-l...