The effect on mood is clear. But Facebook still plays its role in connecting people. For me, it is far easier to write a message to a friend 10km away than to phone him. I also modified my feed, so I have opinions of most good politicians at one place and don't need to rely on news to report on it. Informational value of some pages is like of gold.

It is true that Facebook may emotionally hurt you. It all depends on how you use it.