Symptoms would have to be present in childhood, but that does not necessarily mean academic or disciplinary problems at school.
I personally graduated 7th in my class. (Probably would have been valedictorian without the ADHD.)
I only had one detention in 13 years of school discipline.
However, my symptoms manifested in plenty of other ways.
Mostly socially and at home, but I also had serious organizational and study skills deficits that created drama with me and my parents, but did not impact my grades (until college).
I also ran about 3 activities a day.. (Musical to swim practice to Karate).. I don’t know what would have happened without that type of physical activity.