What is HPPD?

Hallucinogen Persisting Perception Disorder (HPPD) is a rare condition that appears in a small percentage of individuals who have used psychedelics. It is characterized by persisting perceptual disorders such as seeing halos around objects, trailing images following moving objects, and distortions in color. For a diagnosis of HPPD, these symptoms must be clinically distressing and persist over several months. Interestingly, cases of HPPD have been observed mostly in illicit users of psychedelics, suggesting other factors such as polypharmacology or undisclosed substance use may contribute to its occurrence. Notably, HPPD has also been reported in individuals who have never taken psychedelics, suggesting the possibility of a rare neurological susceptibility or being triggered by other substances like alcohol or cannabis 1 .