title: Investigating the mechanisms of hallucinogen-induced visions using 3,4-methylenedioxyamphetamine (MDA): a randomized controlled trial in humans.
abstract: BACKGROUND
  The mechanisms of drug-induced visions are poorly understood. Very few serotonergic hallucinogens have been studied in humans in decades, despite widespread use of these drugs and potential relevance of their mechanisms to hallucinations occurring in psychiatric and neurological disorders.
  
  
  RESULTS
  We investigated the mechanisms of hallucinogen-induced visions by measuring the visual and perceptual effects of the hallucinogenic serotonin 5-HT2AR receptor agonist and monoamine releaser, 3,4-methylenedioxyamphetamine (MDA), in a double-blind placebo-controlled study. We found that MDA increased self-report measures of mystical-type experience and other hallucinogen-like effects, including reported visual alterations. MDA produced a significant increase in closed-eye visions (CEVs), with considerable individual variation. Magnitude of CEVs after MDA was associated with lower performance on measures of contour integration and object recognition.
  
  
  CONCLUSIONS
  Drug-induced visions may have greater intensity in people with poor sensory or perceptual processing, suggesting common mechanisms with other hallucinatory syndromes. MDA is a potential tool to investigate mystical experiences and visual perception.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT00823407.
authors.affiliation: Addiction and Pharmacology Research Laboratory, California Pacific Medical Center Research Institute, St Luke's Hospital, San Francisco, California, United States of America. matthew@baggott.net
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Baggott
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Siegrist
authors.forename: Gantt P
authors.initials: GP
authors.lastname: Galloway
authors.forename: Lynn C
authors.initials: LC
authors.lastname: Robertson
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: Coyle
authors.forename: John E
authors.initials: JE
authors.lastname: Mendelson
mesh_terms: D015104:3,4-Methylenedioxyamphetamine / Q000494:pharmacology*; D000328:Adult; D000588:Amines / Q000737:chemistry; D018592:Cross-Over Studies; D006212:Hallucinations / Q000523:psychology*; D006213:Hallucinogens / Q000494:pharmacology*; D006801:Humans; D008297:Male; D010919:Placebos; D058826:Serotonin 5-HT2 Receptor Agonists / Q000494:pharmacology*; D011795:Surveys and Questionnaires; D014785:Vision, Ocular / Q000187:drug effects*; D014796:Visual Perception
chemical_list: D000588:Amines; D006213:Hallucinogens; D010919:Placebos; D058826:Serotonin 5-HT2 Receptor Agonists; D015104:3,4-Methylenedioxyamphetamine