Experimental Psychiatry. V - Psilocybine, a New Psychotogenic Drug

Introduction

The paper begins by summarising earlier pharmacological work on psilocybine in animals, citing autonomic and central nervous system effects. In intact animals psilocybine produced pupillary dilatation, pilo-erection, tachycardia, tachypnea, hyperthermia, hyperglycaemia, blood pressure increase and contraction of the nictitating membrane; these effects were attributed largely to central stimulation of the sympathetic system. The drug also produced an arousal pattern on the EEG and facilitation of spinal reflexes, while motor behaviour was described as retarded. Earlier human reports, including those by Delay and colleagues, indicated that oral doses in the low milligram range produce a state of inebriation with physical relaxation and mental alterations appearing about 45 minutes after ingestion and lasting several hours. Those reports described a range of manifestations—hallucinations, dreamlike states, reliving of emotionally charged experiences and mood changes—varying between subjects. R. and colleagues set out to add systematic observational data from a small, controlled pilot study in which they administered psilocybine sublingually to healthy male volunteers and recorded mental and behavioural changes. The stated aim was to confirm activity in humans and to characterise the time course and qualitative features of the psychological and neurological effects, using selected psychologic tests to provide objective measures alongside clinical observation.