In view of findings that schizophrenic patients require higher doses of lysergic acid diethylamide to produce psychologic disturbances than do normal subjects,1-7 this study was made to determine whether the absorption of LSD-25 into the central nervous system of such patients, as measured by pupillary dilatation, differed from that of normal subjects.
The recent study of the metabolism of LSD-25 by Axelrod, Brody, Witkop, and Evarts8 demonstrated the presence of considerable amounts of the drug in the brain and cerebrospinal fluid of a cat after intravenous injection of 1.0 mg/kg., indicating that the substance could pass the blood-brain barrier. This was true also in the monkey injected intravenously in a dose of 0.2 mg/kg., where the biologic half-life (the time required for the plasma level to fall to half its value) was found to be about 100 minutes.
A constantly noted phenomenon after the ingestion of LSD-25 is
FREEMAN H. Pupil Dilatation in Normal and Schizophrenic Subjects Following Lysergic Acid Diethylamide Ingestion. AMA Arch NeurPsych. 1958;79(3):341-344. doi:10.1001/archneurpsyc.1958.02340030105017