It does have to impact his ability to access the curriculum. Grades aren’t the only thing though. How is his behavior? Does he get fussed at a lot? Can he sit still?
I hope at least the psychiatrist had you and teacher fill out rating scales. If not, ask for the Vanderbilt scales. He’ll know what they are. You kind of have to see the same thing across settings. (Although some kids really work hard to hold it together at school and then let their hair down at home.
School Counselor and guy with ADHD