Whether there is a neurological factor or not, our kids need discipline, consistency, rules. Do we over-punish? You better believe we do. Not because we're being punitive but because we don't have any other answers and want our kids to be like the kids down the street -- kind, respectful, non-threatening. So, we do the typical parent things. When that doesn't work, we turn to therapy. We're frequently told the fault is not in the child's illness but with us -- we need to be more consistent, firmer, etc. Nope, sorry, that didn't work, now what? If we're lucky, we find something like this board for help.
So, we have a choice. We can beat ourselves up for trying "normal" parenting techniques in the past. We can be angry because we listened to pros who dealt with the typical, rebellious child, not a child with chemical imbalances or neurological issues. Better yet, we can forgive ourselves, we can understand that the therapist who gave us the bad advice was doing the best he could do with his knowledge base and then we can start looking for alternatives.
Personally, I'd be patting myself on the back if I were you. You figured what you were doing was not working and you started looking for alternatives. Strangely, we're far more willing to forgive our kids their major transgressions than we are our mistakes in doing the best we knew how. I forgave my daughter my broken arm, which was done deliberately. I forgave the theft of my father's watch, which was sold and could not be retrieved. I forgave the deliberate damage to our home. I beat myself up for years for things I said or did to her that were never deliberate, but were done because I thought they were the best thing for her or just blurted out when I had reached my limit and nothing I ever said to her was half as hateful or cruel as what she was saying on a daily basis just to hurt. Amazingly, when I learned to forgive me, she did, too.
It really is time to let go of the past. Forgive yourself. Barring having deliberately hurt him physically and I mean deliberately, not when you're in a rage and not in control of anything, not having said the mean, hateful things we all say because we're human and frustrated and angry and hurt, let the past be the past. I can remember basically grounding my child for a year. Do I regret it? You better believe I do but I also understand I was doing what I thought was right and truly was doing the best I could. It wasn't a stellar moment in my parenting skills but I was doing what I thought was best for my child. So did you. Regret but forgive.
RTCs can be great things if they are the right fit. Using a good consultant is a good thing. Here's hoping he can find a good one for you. I'm not convinced I found the right one for my daughter but I am convinced just getting her away from certain influences helped a lot. She did learn some coping skills while there and those skills are serving her well now. I don't regret one penny that was spent. I wish I could have the memories of sophomore/junior years of high school for both of us but her survival was more important.
I regret the days we were apart. They were devastating for me. She was my baby, my heart, my soul. One thought that kept me going during her time away was the fact that I was pretty sure she would have run away and I would have worried that she was hurt or, worse yet, dead, had I not sent her to an Residential Treatment Center (RTC). The alternative was far, far worse than my pain in her not being home. So, when the time comes, miss him but think what the alternatives are. If necessary, write them on a large sheet of paper and tack them to his door to remind you why he is there. Miss him while he is gone but use that time to regroup, find yourself, learn to laugh agan. Hopefully, he'll come back with many useful skills that will help him become more of the young man of your dreams.
Sorry, for the novel but I hope this helps a little.