Not as far as I have heard, read or been told by any doctors. ADHD is simply a lack of control to be able to focus. Its an over stimulation disorder. At least it is with my girls. They get distracted easily, and notice everything going on around them all at once. They are up out of their seats, talking out of turn, and just cant focus. It gets frustrating for them, but as far as I know, ADHD and Autism are not related other than being disorders. I may be wrong, and anyone can correct me, but I am pretty sure its not related.
In contrast to what's written above, there are many people who believe that ADHD and Autism and Asperger's are all part of the same "spectrum" of disorders. From what I have gathered thus far, there can be SOME similarity in symptoms between the disorders. However, there are usually specific symptoms that designate one disorder or another.
I think that there is going to be some debate about this in the medical community for some time to come.
I've never really thought about it, but off hand I can tell you they are both considered developmental disorders. I've been diagnosed with both ADHD (combined type), and Autism (PDD-NOS). As LRM1021 pointed out, there are some people who believe they are on the same spectrum of disorders, while others do not. Certainly there are symptoms that overlap, but the same can be said of many disorders.
The reason I asked this question is that my son has been diagnosed with hyperactivity disorder but I still have a very strong suspicion that there are still alot of traits of aspergers there too. I have heard that a lot of the time adhd can be misdiagnosed initialy(especially if the child isnt too social extracted and displays some social qualities).Also, and I wonder what anyone else thinks of this. Because there are a lot of "cross-over" similaities between adhd, hd and aspergers is it possible that a lot of children already diagnosed with one of these, it it possible for them to maybe have another as well?
From what I have seen, nearly every person on the autism spectrum will also have ADHD diagnosis, but all ADHD people do NOT have autsim spectrum disorders.
It's absolutely possible for your son to have ADHD, and be on the Autism Spectrum. I would recommend you discuss your concerns with your sons pediatrician. He/She should be able to help you find a specialist to perform an evaluation.