I know why caffeine tends to work in reverse for people with adhd! So the current theory goes that in the ADHD brain the receptors for the tired chemicals are actually misshapen so the tired chemical can't plug in properly. However the caffeine is shaped just right so it can plug in and activate the tired receptors (it's like plastic electric outlet safty caps, they get plugged in but nothing happens. The caffeine is supposed to be the safety cap but in our case it's the chemical)