A compound called 1-methyl-d-lysergic acid diethylamide (MLD-41), chemically similar to LSD-25, produces reactions in both Siamese fighting fish and humans that are indistinguishable from those of LSD-25, but with a higher reaction threshold. In fish, MLD-41 is about one-tenth as effective as LSD-25, while in humans it is about one-third as effective. Prior administration of MLD-41 for several days induces tolerance to LSD-25 in humans, suggesting a different blocking mechanism than that seen with crude beef brain extract.
A single 100-microgram dose of lysergic acid diethylamide (LSD-25) produced measurable declines in intellectual functioning among healthy adult volunteers. Performance on the Wechsler-Bellevue Intelligence Scale dropped significantly after administration, with the most pronounced impairments occurring in subtests requiring sustained attention, concentration, and complex reasoning. Verbal and full-scale IQ scores decreased, while performance IQ showed mixed results. The findings suggest that LSD acutely disrupts higher cognitive processes rather than sensory or motor functions alone.
A single 100-microgram dose of lysergic acid diethylamide (LSD-25) produced measurable declines in intellectual functioning among healthy adult volunteers. Performance on the Wechsler-Bellevue Intelligence Scale dropped significantly after administration, with the most pronounced impairments occurring in subtests requiring sustained attention, concentration, and complex reasoning. Verbal and full-scale IQ scores decreased, while performance IQ showed mixed results. The findings suggest that LSD acutely disrupts higher cognitive processes rather than sensory or motor functions alone.