What others have said, I think the stress, economy and season of the year cause many to "lose" it.
I use FB for positive posting and the inspirational posts that others share brighten my day. They remind me where I should be going and trodding spiritually. I got rid of any and all people on FB that whine or complain about life in general or anyone who is negative consistantly. I took all family off except my daughter because my family was causing too much drama and I refuse to be a part of it or to even see it on FB.