Earlier quoted context omitted.
People with ADHD react to amphetamines differently than people without it (at the correct dosages at least; I've never read anything about what happens to people with ADHD that take more than the correct dosage).
This is false and a common myth. If this was true then we would have the perfect test for ADHD, just give someone some stimulants and see how they react.
"Correspondence (letter to the editor): Paradoxical Reaction in ADHD":