Emily, Aine is right on about telling your friend the impact her self destruction would have on you and others; I think it's OK to say it is a very selfish thing to do. She is in so much pain she may not be able to think about it. If the depression has gone on for so long, there is almost certainly a biochemical factor. Find out her family medical history, if you don't know it. Finding the right drug is a start, but they take about a month to kick in. Seed is right about using your body, those endorphins help with depression. Take care of yourself, or you will get dragged down by this. Live, laugh, and love.

One immediate family member of mine committed suicide, and 3 others have made gesture/attempts. Take the talk very seriously. What is the situation with her next-of-kin? They are the ones who COULD have her put in for evaluation if there arer "Danger to self or others" signs.

Good luck.