I have just discovered evidence that my 19 year old daughter is cutting herself and has been for 6 months or more. She doesn't know that I know this, and I can not tell her how I learned of it. How can I help her?
When your daugther is cutting herself, the reward center in the brain is stimulated and her anxiety will be relieved for a short time. Self-harm can sucessfully be treated with Prozac, which reduces the level of anxiety, or with a type of psychotherapy where your daughter can learn how to get in contact with her own emotions and how to bear her pain. She will learn how to meet those feelings from which she used to run away.
Clear your home fram razorblads and other sharp objects that can cause temptation. Spend as much time with her as possible and avoid leaving her on her own. Try to help her find new ways of dealing with life, so she doesn't have to hide from difficult feelings by harming herself.
In order to help your daugther, you have to let her know that you know.