Hallucinogen persisting perception disorder (HPPD) is a rare medical condition that can cause visual disturbances (sometimes called flashbacks) if you’ve taken hallucinogenic drugs in the past. With ...

Callen Ghahramani says he has had persistent visual distortions since trying what he thought was acid as a teenager. His symptoms — severe anxiety and depersonalization — reflect the common features ...

Hallucinogen Persisting Perception Disorder (HPPD) is a cognitive disorder in which individuals continuously re-experience visual and other sensory hallucinations that they first experienced while ...

Hallucinogen-persisting perception disorder (HPPD) causes a person to keep reliving the visual element of an experience caused by hallucinogenic drugs. A person with HPPD has frequent visual ...