"incredible.  i was on adderall for over a year.  my doctor switched me to vyvanse four days ago.  since day one, i have felt better than ever.  that &quot;nervous-jittery feeling&quot; (perfect description) as well as anxiety and teeth-grinding that i had while on adderall is totally gone.  i feel &quot;normal&quot;. i am able to concentrate and focus calmly, and am no longer plagued by excessive energy.  i feel healthy, and everyone around me has noticed the positive difference in such a short amount of time."