Alright..When I was a sophomore I lost a really great friend to some bad people, so I got really depressed. They diagnosed me as "clinically depressed" but really I was circumstantially depressed. Psychiatrists only tell you that you are depressed clinically and that you'll have to take pills to get out of it. This is not true. I became more depressed after taking my pills, I gained 30 pounds and if I missed a pill I would not be able to sleep for 2/3 days. You need to convince your friend that cutting is not at all cool and it gets her bad attention. She should start focusing in some other area. Join a club or a sport together, do things you both enjoy all the time, and get her mind off stuff.
In my opinion, her pills might be causing a detrimental effect for her, so talk to her mom and her about it. Ask her to go to some of her appts. with her, and see if the doctor actually listens to the problems rather than just prescribe medications. I'd say 95% of people are wrongfully diagnosed.