The dependence related to stims is psychological. Depending on your consumption you may never experience a bad withdrawal. One thing people should know is that the increased dopamine brought about by stims is coupled with a decrease in serotonin levels. A see-saw affect I've been told. And believe me you are not good without a fair amount of serotonin.
So there will be stretches where the addict is out of commission where all you want to do is sleep and depression is there for you when you wake up. The one difference among the prescribed stimulants is with Ritalin. It targets dopamine more so than norepinephrine so you don't get much of an energy kick but you also have a slightly better chance of avoiding heart troubles