I wasn't aware of the extent of his injury, and I am sorry he was attacked. I hate that he had to go through that. I do think we are learning a lot of info about the long term problems from concussions and that it may be a factor that will have to be accounted for in future therapy. I also think that the trauma from the attack could make the "escape" caused by drugs seem very very appealing. It sounds like that might be a huge issue and something that has led to his drug use. I do think you are right in that he has to WANT the help before any of it matters.
From experience, having records of what has gone on WILL help when he wants help. It isn't like you can forget it, but hang on to the info and when he is ready, be sure that the counselor knows.
I know what you mean about having a list. I always feel better with a questionable situation when I have a list. I really hope that he can see how bad the road is before much longer.
I truly admire the strength that you have handled this wth, and the grace. I know it doesn't feel like it from your point of view, but you have done the best job possible of handling this. You didn't give endless chances, you didn't enable for years and years, you faced the problems and took the best actions to allow rational decision making and to NOT drag the chaos out or inflict too much of it on the other kids. You didn't hide your head in the sand and pretend that it was a "normal" phase either. Your sons are blessed to have such strong and caring parents. ALL of them.