my worst experience would have to be taking 12 time released 15mg dexedrine (dextroamphetamine a bit stronger than adderal)... I stayed up for 3 days and wasnt even feeling good, had a terrible pain in the top right side of my head... like my brain was bleeding or something horrible...

other than that I used to pop them like crazy in high school... sometimes taking 8 pills 20mg a piece not time released over the course of a day or so... I remember staying up laying in bed almost crying because the comedowns were so bad... I'll stick to weed