Didn't know about the nicotine angle though, kind of interested in the research on this.
That is during elementary school I was grouped with kids that had ADD/ADHD for some counselors/teachers/doctors to learn about us. There was clearly two groups. The kids like me (ADD) staring at the ceiling fans, flowers, whatever and the other kids (ADHD) who were running around trying to tear apart the fans, flowers and whatever.
The problem with getting the label of ADHD is that all of the sudden people suddenly think they observe hyperactive behavior with you. That is they associate hyperactivity with you. So anytime you express an idea excitedly or thoughts come quickly and you are trying to express them to some one (which is challenging particularly if you are an introvert) people call it hyperactive behavior.... the same word for behavior such as running around punching kids, tearing shit up and acting like a 2 year old. Hopefully you understand why I don't like the association even it if is academically correct.
It was just, "oh, his GPA's low? Seems like he can't focus? Here are some amphetamines, have a nice day!", with zero follow up about whether the medication was doing its job (didn't matter -- I never took it anyway).
In my experience in other countries, the primary difficulty for ADHD support groups is that many country's medical institutions do not even acknowledge ADHD as a thing.
Some of these institutions acknowledge, but seem to believe that the condition disappears when you turn 18.
Many of the regulatory institutions don't allow stimulants to be used for treatment, either.
This is mostly an anti-scientific position. ADHD is extremely well-researched. Its (medication-based, not CBT) treatment is the most effective of any mental illness, more so than "understood" things like depression.
I'm biased, but I think a lot of places are still in denial about ADHD. There's way too much research around the illness and its effects and treatment.