What is HPPD (hallucinogenic persisting perception disorder)?

Hallucinogen persisting perception disorder (HPPD) is a chronic (and often permanent) condition where a person feels or sees what they felt or saw during a psychedelic trip. Often it causes problems with vision and sound perception. HPPD is only caused by prior use of hallucinogens.

There are two types of HPPD:

  • Type 1 HPPD This is where people experience HPPD in the form of random, brief flashbacks.

  • Type 2 HPPD People with this kind of HPPD experience ongoing changes to their vision, which may vary in intensity.