He was on a few different medications but my breaking point was the day that I had to physically restrain him because he was trying to hit me. He is normally a happy child. He can be very emotional though, especially when he is tired. I don't know if I would say that he has anxiety per se, but he does worry about things that 8 year olds shouldn't think about..like me getting old, passing away, war, the end of the world, etc. It's also usually when he is tired and emotional that he thinks about those types of things.
Anyway, I decided that even if I had to tell him to sit down/sit still/focus on the task at hand hundreds of times a day, I'd rather do that then change who he is as a person.