I still don't understand how anyone can consider it being part of the Autistic spectrum when it doesn't include the core autistic traits of social impairment and repetition. Can someone explain this? Executive dysfunction and problems regulating attention are basically a common part of autism too(meaning that most of us can also be diagnosed with some sort of adhd if that extra diagnosis is useful), but they aren't what it is defined by. If someone who has great natural social skills and well-rounded "normal" interests(like many with ADHD) can be autistic, then the word no longer makes sense. If we're going to add ADHD to the autistic spectrum, it makes just as much(if not more) sense to also add some other groups that share a few traits with most autistic people(yet not the main group of traits) like: people with OCD, people with Sensory Processing Disorder, people with Social Anxiety Disorder, Schizophrenics, people with Stereotypic Movement Disorder, people with almost any personality disorder, introverts, people who cut the tags off of their clothing, etc.
Note: i'm diagnosed with both AS and Inattentive ADHD. I think an ADHD diagnosis is good to have if you meet the criteria and it creates a significant issue for you, because it's useful in creating a better picture of your behavior and your mind. I still see my ADHD symptoms as also part of my AS, but since those symptoms aren't included in EVERY case of AS(or at least not to a particularly significant degree) it still seems more complete to have both diagnoses. It would NOT, however, make any sense whatsoever to declare me autistic based SOLELY on those ADHD symptoms that i have... Nor would it make sense to declare me autistic based solely on my sensory issues, or even solely on my obsessive interests. I'm autistic because i have the social issues and repetitive behaviors/obsessive interests, along with sensory issues, executive functioning issues, and everything else. I share some of the way i'm wired in common with people with ADHD, but there's a lot of stuff along with it too.
I CAN see it being classed as some sort of developmental disorder.. Just not as a Pervasive Developmental Disorder(or Autistic Spectrum Disorder), because those have to do with social development, flexibility, etc.