dman
same thing happened to me. definitly keep him busy, and get him involved in other things...tell him to make friends in school, let him do what he needs to be happy.
it's a shame, but obvious that they are finally shutting him out.
professional help may be the right thing to do, but talk to him about it first...just don't assume. He may be proud, and his pride may be one of the few things he has left. If he thinks that you and him can work through it together, try that first.
This is just the first thing that is happening to him to show that he is in a world of bastards, with a few good people in it that he can trust, including you.
Like I said, I got through similar, and worse situations, with suicide being the only consolation in my mind for a couple of years. I got through it on my own, but he may not be able to...
good luck to you
ashi