My Son has Aspergers- Pre-diagnosis

My 26 year old Son has Aspergers. He was not properly diagnosed until the end of 8th grade. By that time he had been told he was deemed "un-teachable" in public school and had just completed his first year at a Private School for children who were diagnosed as behaviorally, and emotionally challenged, or struggled with a learning disability.
This Private School informed me after his 1 year there that my Son was a "challenge" that they were were not equipped to handle. During that 7th grade year, they had become convinced that he had ADHD, and so I took him to a psychiatrist to see if indeed he was ADHD. I want to add here that this was not the first, nor was it the last time my Son had been to a Dr., therapist, Social Worker, or other Mental Health Facility, in search for answers, nor would it be his last.
After many visits and tests this psychiatrist was convinced my Son did not have ADHD. He was depressed, anxious, had OCD, and more than likely oppositional defiant disorder, but in no way, was she willing to put him on a drug for ADHD, which the school felt he needed to be on. Of course, I realized then that what the school wanted was for my Son to be "drugged" into a more cooperative,
student. He was often belligerent, and out of control and they became frustrated with him on a regular basis.
At the end of 7th grade the director of the School let me and my Sons Step Father know that they would not be able to have him back the following year. As we talked this director said that he reminded her of a student they had taught a few years prior, who had Aspergers. This was the first time I had ever heard of Aspergers. It was 1999, and Aspergers was fairly unknown then.