Is the ADHD diagnosis based on these scores? Or reported behavior? Or both?
Was the psychologist one who specializes in gifted?
Do you agree with the ADHD diagnosis?
I think there is a lot of info they have nowadays in regards to addressing behaviors before medicating, so that is good.
There are several on this forum who also have children with ADHD who do have their children take medicine and have been successful with that course. Perhaps they can give you some more guidance.
Definately, GT placement is a given.
That VCI especially is WOW!!!!!!! Scores of 18 and 19 are considered to be topping out, so even that 152 could feasably be an underestimate!

Exciting news and sometimes a little overwhelming, yes?
Good luck with your communications with the school.