...Kay Redfield Jamison has a new book out called "Night Falls Fast". Her premis and one I have found to be chillingly true in my practice is that many dangerously suicidal individuals are manic-depressive (or Bi-Polar I or Bi-Polar II.) Correct diagnosis is crucial because medical treatment can and should vary depending on the individual's diagnosis. Diesel gives good advice. Depressed people need contact, connection, attention, love, caring, prodding. Help your friend stay connected to her community and friends and get her in to see a GOOD psychiatrist ASAP for medication and an expert therapist for therapy....good luck