Ok I do have an ADHD which was diagnosed when I was 8. SO I can speak from first hand experience.
My parents refused to put me on stimulants until I was in high school when the demands started exceeding my capabilities. However, I find deciphering ''level of impairment'' by looking at ''academic/school/work performance'' rather simplistic and not capturing the true extent of ADHD symptoms. Until high school I was A+ student but I had significant level of impairment because I was impulsive, messy and disorganized, emotionally highly dysregulated and easily bored which led to significant isolation and bullying. It is when my grades went from A+ to A- my parents started worrying about my functioning and my journey with ritalin started. My school grades did not improve whatsoever but I became much less bored, more organized, more attentive in interpersonal relationships, emotionally more stable and much less impulsive which led to making actual friends and improving my relationship with my parents.
To this date, I have been on and off various stimulants. Can I function as a psychiatrist and perform well at work without stimulant ? Absolutely yes. So unless it is digged deep, some could claim that I overcame ADHD just by looking at my work performance. What most folks miss is that untreated ADHD wreaks havoc interpersonal relationships and emotion regulation. You are much less mindful and attentive to social cues externally. You can cover this at some extent but people who are close to you sense this rapidly. Internally, boredom and inner restlessness eat you up and you find yourself constantly seeking the ''thrill'' that no work I know of can give. This seeking sometimes lead to dangerous impulsive behaviors like promiscuity, drug seeking and high adrenaline activities.
So when I am off of my stimulants, pretty much nobody can see the difference in my ''performance'' from outside. But people close to me know very well that I am off of my stimulant when I turn into an emotional wreck and reckless adrenaline junkie.
I can definitely relate to this, and absolutely agree that an assessment of impairment levels in ADHD should take into consideration more than just one or two areas of a person's life.
I was diagnosed around the age of 3 (yes I realise that is highly uncommon), but still went on to manage reasonably well later on at school from an academic point (profoundly gifted, yada yada yada). I say 'reasonably well', because whilst I got the grades, it was still a major struggle for me to actually sit through a class, follow instructions/directions, hand work in on time, and so on. Other areas of my life (social, emotional, etc) were an unmitigated disaster. Someone merely looking at the nice little row of A's on my school reports might be forgiven for thinking everything was hunky dory when nothing could have been further from the truth.
Fast forward to my 20s & whilst I was no longer (quite literally at times) bouncing off the walls hyperactive, I was still nowhere near what anyone with half a brain would've described as 'functioning well'. First time I got behind the wheel of a car for a driving lesson I got distracted and zoned out to the point where I completely forgot I was in a car, driving along a road - ended up pulling out of a side street, and across 4 lanes of traffic without even realising (needless to say I don't drive now). Social events usually started with a quiet forewarning for anyone who might be meeting me for the first time, because I'd be talking to someone, get distracted and literally wander off in the middle of a conversation. Tried attending University and, well, let's just say I didn't go back for a second year (couldn't sit through lectures, couldn't keep my notes organised, often times spent the entire day being so distracted by anything and everything that I just literally forgot I was actually attending University). Now as with my academic grade performance as a child, I did also do contract IT & web design work during this time, as well as working as a bar tender, and I was darn good at those jobs. Talk to my employers at that time and you likely would've been given glowing references in terms of what a good, fast, reliable and hard worker I was. Anyone looking solely at my work history and/or references would've been forgiven for thinking I was going great guns - when that was nowhere near the actual truth of the matter.
Anyway, thank you for pointing this sort of stuff out. I think it's important for people to know, and understand, that functioning well with ADHD is more than just academic and work performance.