Background and ojective: Exploring differences in visual disturbances and triggers between Hallucinogen-Persisting-Perceptual-Disorder (HPPD) Type I ("positive/benign") and II ("negative/distressing").
Methods: Forty individuals with HPPD and prior LSD use completed clinical questionnaires.
Results: The most common type of visual disturbances among individuals with HPPD I and II was slow movement of still objects and trailing phenomena, respectively. Those with HPPD I were more likely to report experiencing disturbances in dark environment, while looking at a still or moving object and during sexual intercourse.
Discussion and conclusions: HPPD I and II differ in terms of visual disturbances and triggers, possibly representing different phenomena existing on the same spectrum.
Scientific significance: Our study indicating differences in triggers to HPPD I and II adds to existing literature on differences in visual disturbances between the two subtypes. Further research elucidating additional differences between the subtypes of HPPD is needed. (Am J Addict 2017;26:568-571).
© 2017 American Academy of Addiction Psychiatry.