Carnation, I will say a prayer for you and your son.
Throughout elementary, high school, and college, almost all of the dummers that I have met have been ummmmmm....not sure how to put this..... either just totally nuts, or stoners/troublemakers of some sort. In elementary and HS, they were the kids always getting in trouble, smoking pot (well, HS, not elementary), etc.
Also, hope you can deal with him banging on things all the time and playing air drums.