Any past testing can be helpful- as generally a diagnosis is made [should be made] on symptoms present throughout childhood to present and their impact.

..I was an interesting child. Looking at some of the testing I did even as young as six, it is pretty typical neuropsych profile for high functioning autism.... but that wasn't very common a notion so they kept testing about everything when things came up.

I had a couple neuropsych tests done and a personal history and input from my mother and then the neuropsych testing and school stuff [as well as developmental milestones] that all played a part in the diagnosis. It went from r/o asperger's to PDDNOS and then HFA- which has been the case with the last few providers or whoever feels like evalutating me for whatever reason.

If you have records or something relating to functioning as a child, that may be helpful. All providers do things differently but it is often helpful with diagnosis of ASDs.