LSD-associated "Alice in Wonderland Syndrome"(AIWS): A Hallucinogen Persisting Perception Disorder (HPPD) Case Report.

A side effect associated with the use of LSD is the return of perceptual disturbances which anteriorly emerged during intoxication, despite absence of present use. Here we present the case of a patient with a previous history of sporadic and recreational cannabis, alcohol and LSD consumption who reported LSD associated "Alice in Wonderland Syndrome" (AIWS) or Todd's syndrome. AIWS is basically characterized by four frequent visual illusions: macropsia, micropsia, pelopsia and teleopsia. AIWS only appeared during LSD consumption and continued after LSD suspension, namely, Hallucinogen Persisting Perception Disorder (HPPD). This phenomenon did not cause a major functional impairment but provoked sufficient worry and concern due to its persistent continuation. The patient refused medical treatment and continued psychiatric follow-up. At the one year follow-up he reported complete remission. To the best of our knowledge this is the first reported case of AIWS which persist after LSD interruption (HPPD) in the professional literature. Reasons for this intriguing, benign, reversible and apparently harmless side effect are proposed.