Just my perosnal 2 cents, i am not medically qualified and don't give medical advice, diagnosis are as good as the doctor that gives them. It's my conviction based on the stacks of material i've read that ADHD does exist as a condition but it relatively rare. I'd say that about 80% of diagnosed cases are just people that needed a label so they gave that one. A kind of catchall for unruly people.
Afaik there are indeed many Aspergers with other diagnosed issues. I tend to think that it's merely another aspect of the Aspergers that they missed classing with the syndrome and subclassed as something else.
I totally disagree with Aspergers being a form of autism as well. It just has overlapping symptoms. Latest research on schizophrenia for example shows white matter anomalies not unlike Aspergers or Autism. So as much as Schizophrenia isn't Autism, so is Aspergers.
The entire medical profession seems to think other wise, they went as far as to scrap Aspergers altogether, but to me that only shows how little they understand of the syndrome.
But then again, what do i know. But i'm very skeptic about all these co-morbid diagnosis.
There's only two things I hate in this world. People who are intolerant of other people's cultures and the Dutch.