This touches home base. 2 of my friends committed suicide the past 3 years (2009, 2010), due to untreated or misdiagnosed depression and other issues. In December of 2012 my 17 y old daughter attempted suicide, for no apparent reason as per the "specialists" "opinion". Since my daughter is not with me, for the first time in my life I've experienced the true feeling of loosing someone very dear to me. It's like the Universe crushes your last breath out of you and there is nothing you can do. It's easy to judge depressed people and to brush it aside. It is very hard to understand it and know how to support it, especially when the person with depression does not want any help.
That is awfully rough. May you and your daughter find a way through.