"Folks with ADHD"

ADHD symptoms are a matter of degree in most individuals so presenting it as a binary is a fallacy. The vast majority of people can experience some benefits from some dose of stimulants (see the widespread use of coffee which has different effects but is analogous). I believe the reason the idea that people with ADHD respond differently is popularized is to legitimize ADHD in the eyes of people who would be judgmental regarding medication that causes cognitive enhancement in "healthy" individuals as well. (Because using performance enhancing drugs is cheating or some such nonsense)

Edit: See http://www.nature.com/nature/journal/v456/n7223/full/456702a... http://www.nature.com/news/2008/080409/full/452674a.html