I had to reply to this.

I believe people can learn self harming from therapists, and other clients in treatment programs and psychiatric inpatient units. When you put people together with similar issues they can teach each other how to self injure. I have seen it and the competition between patients. The behaviors are usually reinforced by other clients and medical staff, which may lead to addiction. Even the harmless questions asked by a therapist about self injury can give a client who has never self injured before some ideas.

Some people don't do well in group homes, psychiatric wards and partial hospitalization programs. Sometimes they end up walking out with a lot more problems. There should be pre-admission screening to identify vulnerable, sensitive and impressionable individuals.

Therapy isn't always pleasant. It can be challenging and depressing at times but it should never teach you self injury.