I quite honestly believe that Facebook contributed to -- or was responsible for -- the ever growing rate of depression. This type of behavior has led numerous people to participate in degenerate activities instead of contributing something to society. Social media may have started well but now it has morphed into becoming the cesspool of the internet.
While I think that Facebook is horrible I'm not too sure in thinking that it's the biggest reason. I think the advance of technology is rather more responsible for the current state and if it weren't Facebook it would be something similar with another name. Contributed surely but not responsible imo.