Probably a good psych or neuropsych is the answer. I don't want to look back and think it would have been useful for her to have a dx at this age. Last year, OASIS turned me onto a group here who does AS services/counseling/groups, and they thought she fit AS, but they had a MSW doing intake, so I was really disappointed because I thought her opinion was really no better than mine. And what they offered her was social skills groups, which is really the area where she fakes it the best. One on one and in small groups her quirkiness is more obvious, but I think her friends accept her as she is. It's more in the areas of intimacy, obsessiveness, alienation, anxiety....You know!
I have had the same story as your son in terms of every dx under the sun over the past 20 years or so. I find it humorous that I'm now on Risperdal, which I believe is the drug given most often to people on the spectrum.
Thank you for the ideas