Mental health professionals simply didn't know what to do with them. Instead, they use talk therapy to help them learn to take responsibility for, and control of, their actions. As treatment for self-injurers becomes easier to find, friends and family can play a more active role. Please know you are not alone and this does not need to remain a secert. Please take the time to talk to your family, teachers, or other adults so the hurt can end.
Additional resources are available.