"i&#039;m a rare case; i currently am prescribed 180mg of adderall (90mg ir &amp; 90mg xr). when this was raised to 240mg, i asked to try dexedrine thinking that after a decade on adderall, i had simply become tolerant to it. my doc put me on 120mg of dexedrine. there was a noticeable decline in my focus, and my energy levels (not that&#039;s why you should take stimulants) fell off the map. it was smooth. but for me, it was way too smooth. i remember taking 60mg one morning and then going for a hike. i couldn&#039;t concentrate on a damn thing, and i was nodding off as i was walking. i guess i should have expected this going from such a high amount of adderall to a lower dose of dexedrine (which is absent of levoamphetamine). i would try it again though."