How to be a supportive friend if your friend is depressed/cutting?

One thing you can do is tell them your always there to talk whenever they want and insure that you will keep their secrets. Try to do things with them, but only you and the other person because more than one person can become overwhelming. Maybe go on a walk or a quiet and calm place. You need to give the other person a reason to live and tell them how wheather they know it or not people love them and nobody would want to see them go.