I am no expert on self harm, but from what I've read in the published literature, yes, more prevalent amongst teen girls, and teens generally. It's a form of release. I link it more to an anxiety issue than depression, although these conditions are often comorbid. It seems to be a way to transfer all the pent-up angst into a physically release. The mind associates relief of mental pain with directing physical pain. If I were to create an analogy, I would presume it would be like nausea - everyone hates to throw up but by god you feel such intense releif when you do.

I think self harm/ self injury is parallel to Other methods of escaping from misery - substance abuse, violence against others. Many of us never seek these 'outlets' that would only cause deeper misery. People are just different in coping, have different coping skills.

If someone who self harms and feels like I'm off base, I mean no offense. Just thinking through it aloud. I'm sure there is more complexity to it.