As an adult recently diagnosed with a marginal attention defficit, who has recently started a perscription of dexies, I really think I'm missing some trick even

As an adult recently diagnosed with a marginal attention defficit, who has recently started a perscription of dexies, I really think I'm missing some trick even more now. The only results I've seen so far are extremely subtle (general feelings of lethergy have reduced slightly, generally a little more content / less depressed, can read for longer periods of time during the day without falling asleep) only after weeks of taking concistently, the first few days I didn't notice anything. Nothing like the sudden surge of focus and energy described here after taking a single dose. What quantities are these kids/young adults taking to get this effect?