Visual phenomenology of the LSD flashback

Arch Gen Psychiatry. 1983 Aug;40(8):884-9. doi: 10.1001/archpsyc.1983.01790070074009.


One hundred twenty-three persons with a history of LSD use were studied for the presence of the LSD flashback phenomenon and compared with 40 control subjects. A syndrome emerged that included ten distance visual disturbances. It had lasted for five years in half of the population, was treatable with benzodiazepines, exacerbated by phenothiazines, and precipitated by 19 different stimuli, most commonly emergence into a dark environment. Sensitivity to LSD as determined by flashbacks appears to divide the study sample into three discrete subgroups. There may be a genetic basis to LSD sensitivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adult
  • Anti-Anxiety Agents / therapeutic use
  • Antipsychotic Agents / adverse effects
  • Benzodiazepines
  • Female
  • Hallucinations / chemically induced
  • Humans
  • Illusions / chemically induced
  • Lysergic Acid Diethylamide* / adverse effects
  • Male
  • Mental Disorders / genetics
  • Perceptual Disorders / chemically induced*
  • Perceptual Disorders / genetics
  • Phenothiazines
  • Phosphenes
  • Substance-Related Disorders / complications*
  • Substance-Related Disorders / psychology
  • Visual Perception* / drug effects


  • Anti-Anxiety Agents
  • Antipsychotic Agents
  • Phenothiazines
  • Benzodiazepines
  • Lysergic Acid Diethylamide