Psychiatric hospitalization is used as a last resort in the treatment of DSH. Hospitals provide an artificially safe environment, which can actually compromise the therapy techniques of understanding feelings and coping with the same in the real world.
Remember that physical and sexual abuse is a major contributing factor in DSH. Ask the subject if they have been abused, how, when, where, and by who. If you suspect abuse, make a report to Child Protective Services and send a copy of your report to the appropriate detective. If your department has a psychiatric team, refer the subject to them as well for follow-up.
Self-harm scares people, especially loved ones. The behavior is disturbing and difficult to understand. Encourage family and friends to educate themselves about the disorder. Demands and ultimatums will deteriorate the situation further. A link below will provide you with a comprehensive list of online resources you can share with subjects and their loved ones.