ADD/ADHD is a really difficult one cos it can mask so many other things eg dyspraxia (bumping into things & tripping over the brick in the playground), autistic spectrum stuff etc
I was reading your post and nodding away - I've look after a 14 year old with ADD and he can be anything from lovely to a complete nightmare - and he has got violent in the past.... he comes with brother who protects me from the worst of it! He doesn't like incentives, won't sign or keep to behaviour agreements, makes fun of others, is unable to communicate with some of the other children - incl my son..... WATCH him with little ones cos he might one day do something stupid like drop his trousers to rearrange himself in front of a 3 year old!!
I have worked closely with his father (mother off the scene), his school and his consultant and nothing much has improved over the 3 years I've minded him ....
Then he was put on medication and he has stabilised quite a lot - less mood swings, more able to control impluses....
It's always a risk with ADHD - there's a lovely story I read a while ago - 'a butterfly in my pocket'
http://www.underfives.co.uk/CWGADHD.html
Sarahx