@Aerliss@PossiblyAutistic@dzwiedziu@actuallyautistic when I was diagnosed for ADHD 20 years ago the way my psychiatrist tested me was he sent me home with a prescription for Adderall and a follow up appointment a week later. When I came back in the following week describing how drastically my life improved instantly after trying the Adderall he clapped his hands and said Yep you have ADHD.
Years later when I moved away and came back and I needed a new provider, my new provider made me go get an EKG before she would prescribe medication.
These are the only tests I ever had related to that diagnosis.