Hallucinogen persisting perception disorder, what to do?

Mostly wait it out: Hppd is when the use of a hallucinogenic drug leads to ongoing effects long after the drug was last used. There's no generally effective treatment other than waiting for it to subside, although some patients improve with benzodiazepine tranquilizers, anticonvulsants, or parkinson's meds. Good sleep, low stress, ; of course not using hallucinogens anymore may help too.