Study = 9 healthy volunteers, 50mg of amphetamines, all became psychotic in 7-45 hours, but recovered after 6 days - pps had negative emotional reactions (e.g., paranoia or delusions), the pps given paper to write, they're writing pretentious stuff which was fragmentary
Another study = found 40% of amphetamine dependent pps reported sz like symptoms, but abstinence removes symptoms