Injecting 5-hydroxytryptophan before lysergic acid diethylamide reduces the psychological effects of LSD, supporting the hypothesis that serotonin acts to diminish those effects. Placebo-controlled psychological tests showed this reduction.
This analysis examines an experiment by Brengelmann, Pare, and Sandler that investigated whether 5-hydroxytryptophan (5-HTP) alters the effects of lysergic acid diethylamide (LSD) as measured by psychological tests. The discussion focuses on problems with measuring and validating the concept of LSD-induced psychosis, questioning whether psychological tests can reliably capture the drug's effects.