Comparing triggers to visual disturbances among individuals with positive vs negative experiences of hallucinogen‐persisting perception disorder (HPPD) following LSD use

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)