"after being on adderall 40mg a day, doc switched me to vyvanse 50mg and although adderall worked great i found it only working 4-5 hours for the ir and i was feeling nothing from taking the xr. i take vyvanse for adhd, depression, and chronic fatigue from ra and ebv, vyvanse is amazing, no crash, no high and low just an even fluctuation through an entire 12-14 hour day! i feel motivated enough to concur my day but i&#039;m not crawling out of my skin ! love it !"