Taking too much stimulant of any kind can cause heart palpitations, jitteriness, restlessness and anxiety in anyone, whether or not they have ADHD.

But when I took my first dose of Ritalin, I did have that "calm" effect almost immediately. When I took the second dose a few hours later and went to the mess hall, I could actually taste my food (all the time I had just thought food all tasted the same)! Did anyone else out there have that experience?