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August 1983

Visual Phenomenology of the LSD Flashback

Author Affiliations

From the Departments of Psychiatry, Harvard Medical School, Massachusetts General Hospital, and St Elizabeth's Hospital, Boston.

Arch Gen Psychiatry. 1983;40(8):884-889. 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 distinct 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.

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