She's obviously depressed. When I say depressed I mean clinically depressed. As others have said, suggest to her that she should seek out some professional help. Most universities have programs set up to help their students deal with mental health issues. I would contact the student health center or possibly the psychology/counseling department at her school to see what is available. Of course, if she has decent health insurance she can go to an independent psychiatrist/psychologist. In any case, all you can do is suggest that she do these things. If she won't take you up on it then probably the best thing you can do for her is become a part of her life again so that you can offer as much support as possible as a friend.