I call it “Burn the witch” mentality about medical issues.
I run into it with clinical depression (in the extended family). People will make inane comments such as "Nothing a brisk walk around sunrise won't cure", as if any serious psychiatric condition is nothing more than a passing mood. Funny thing about ADHD, I could probably use a little more of it, being to the low energy side myself. Never had trouble concentrating, can do it happily for hours to the exclusion of any distractions including spouses and offspring! (tongue in cheek)