If one has ADHD, then an amphetamine, paradoxically, helps you calm down.
It’s a weird thing that a stimulant can help you chill; from this one could conjecture that an amphetamine to keep you awake isn’t being used to treat ADHD.
I am not a medical Doctor; I am not many things.
Although it would appear that A&E and GP Drs around here aren’t up on lis-Dex