The way that 95% of us would deal with this issue is to make sure that there's nothing in his records and then check the NO box.
I'm not joking. You're asking for an extreme amount of butt pain if you check yes to anything in the health questionaire.
As an elementary school student I took ADHD medication for a couple of months.
By the time I was a college student, there was nothing about it in my medical records and I've never mentioned it to a flight surgeon.