Hi A.,
I am sorry to hear about your sons problems however I have a 9 yr old who has adhd combined typed, ocd,odd,ptsd,anxiety disorder, sleep disorder, tourettes syndrome associated with severe tic displaysia. So I know exactly what your going through, even though they have these problems it makes them more special than they already are. There really is nothing else you can do except keep positive, these disorders take over and display them selves, it's not easy having a child with problems when it comes to other children because they don't know how to deal with it, as far as kids making fun of him I have been down that route and you just have to explain that our children are different in a special way and you should try to find children for him to play with with similar conditions, I have done that and found my son does so much better then with other children, as far as school goes the school and special ed should be involved working with him and eventually he will progress, good luck with the after school program my sons walked right out of it and no one could find him he hated it so much, he has been hospitalized 2x's because of his conditions and so far the last hospitalizion has worked along with med change.It is definitly ok for your son to play imiginary by himself there safer that way just if you can try to take in some of the conversations he has as he's playing alone with his imiganary friends is what i call them. this is something a child tends to do when they feel left out of the crowd they make up their own friends. I hope I was some help to your questions Good Luck and if you need anything please feel free to contact me.
Sincerly,
D. F