Have you read much on Gifted Aspergers? Please take this in to consideration when considering aspergers. Much of the information out there is not geared toward gifted aspergers. It will make a difference. If you haven't already please read Giftedness and Asperger's Syndrome: A New Agenda for Education by Shelagh and James Gallagher. You can google the title. Pay particular attention to the tables listing differences between them. It also includes the Diagnosis Criteria for Asperger's Disorder. Your child would manifest two of the six in A, and at least one of six in B, you then need to be able to answer no to C,D,and E. Your child does not need "all" of them by a long shot.
From there you need to determine if you really need a diagnoses or just go with what treatment might be warranted for the existing symptoms. My oldest DD9 has gifted aspergers and the accompaning or coexisting ADD, mild to moderate ODD based on ACTers testing, and SID. We have used meds at the beginning and gave up, they helped in her opinion but not enough to warrant dealing with the side effects over time and we couldn't find the right dose to eliminate the side effects. I'm not ruling them out as a possibility in the future but not for now. We are using behavioral modification and working with the speech therapist on social skills and pragmatics, in particular with a new book out that is really good. It's a pictoral representation of appropriate social skills, many people have asked the name and I need to find out this week when I see her.
One of my DD6's is also "on the spectrum". We tried drugs with her and took her off as well. It can make for an interesting day at times, and we plan to test her in the next year to see where we are there. The school had made a big push to put her on meds. We are using Brain Ware Safari right now and seeing some progress with her attention and impulse control. You can find information on it on their website if you click on professionals and then on the left hand side click on behavioral impact. We purchased it through the homeschool buyers cooop for very little compared to their regualr prices.
Just so I understand completely, is the current diagnosis ADHD and OD?