People with a d h d have impaired dopemin activity. Stimulant medication increases the activity of stimula of the p f c and allows you to actually focus on one thing. So it doesn't actually speed up the brain. It actually boosts your p f function, which in turn will allow you to negatively inhibit, like, other thoughts and impulses. The problem is that this effect is temporary. overtime, as you use drugs, they stop increasing dopemin over hered. And so when i increase my drug use, it actually has a paradoxical effect to decrease dopamine and then makes the a d h D worse.