A case report describes the experience of a congenitally blind individual, BP, after using LSD. BP reported no visual hallucinations, but instead experienced novel sensory alterations in other functioning senses, consistent with synthetic synesthesia and crossmodal correspondences. The absence of visual hallucinations and the low rates of psychosis observed in the congenitally blind population suggest that acquired visual experiences may be necessary for visual-like hallucinations, and that psychedelic-induced synesthesia can manifest through non-visual modalities.
Low doses of psilocybin (0.5 to 4.0 mg) produce perceptible pharmacological effects without causing hallucinations, cognitive impairment, or increased anxiety. In a Phase 1 randomized, double-blind, placebo-controlled trial, 56 healthy adults received a single oral dose of psilocybin or placebo. No serious adverse events occurred; side effects were comparable to placebo, mainly somnolence. Psilocin appeared rapidly in the blood with dose-proportional exposure and a short half-life. Subjective drug effects were dose-related and distinguishable from placebo at or below 2.5 mg, but hallucination and altered-states scores remained low and not different from placebo.