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 ...

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 ...

Psychedelic drugs are seeing a surge of interest from mainstream medicine, and initial results suggest that psychedelic-therapy can be a safe and effective treatment for some mental health conditions.

Those who have used psilocybin or LSD may be familiar with the experience: The day following your trip, it’s back to reality, yet there are still glimmers of your previous day’s journey, a fleeting ...

Ed Prideaux is a writer and researcher based in the U.K. who specializes in the study of hallucinogen-persisting perception disorder, or HPPD, and the mixed psychological and cultural effects of ...