http://www.medications.com/effect/view/30203 Adderall Xr 20 mg, after a few hours i am so exhausted i can barely stay awake. but at night , evan as exhausted as i am i can't seem to fall asleep Thu, 11 Sep 2008 21:47:53 -0400 http://www.medications.com/effect/view/30203?item=12286 Simple, your brain is too active to fall asleep. Adderall increases the speed of the signals in your brain causeing you to be more focused, this also prevents sleep because your brain is too active. I suggest laying down and taking deep breaths, slow your http://www.medications.com/effect/view/30203?item=12286