Hi. Welcome to the boards
I have gone through CBT, DBT, inpatient and outpatient.. I can tell you that they all work differently for each person, however, in my experiences, CBT and DBT together were really beneficial. I learned a lot about myself and my triggers and what works for me and what doesn't work for me with those classes. Inpatient honestly made things worse for me. And Outpatient as in one on one, is helpful in expressing myself and being held accountable by my therapist. Lasting effectiveness of these treatments.. Well, at my worst in my battle with self harm, as long as i was in treatment, i was doing better. CBT and DBT remain in my mind all the time and when i get urges, im able to stop and think about the things i was taught in the classes, so I think those are pretty effective.
Hope this helped somewhat.