Yeah totally, I meant dopamine released by synapses going up on x-y axis then it reaches a peak and comes down. More amphetamines will keep your dopamine levels above baseline but there is a point of diminishing returns (therapeutic dosage), then once your last dose runs its course your dopamine levels fall precipitously and crashes down below your baseline dopamine levels also known as 'withdrawal' period until you get back to your normal baseline. The more amps you take, the harder you crash down below baseline and your adhd symptoms return and feel much worse as you have less freely available dopamine.

That's all I meant by what goes up must come down :)