Zurich Open Repository and Archive (University of Zurich)
January 1, 2019
Felix Scholkmann, Lisa Holper, Katrin H. Preller et al.
6 citations
Psilocybin (17 mg) was given orally to a 31-year-old man, and functional near-infrared spectroscopy (fNIRS) measured brain hemodynamics and oxygenation over the frontal and occipital cortex before and 30 and 60 minutes after intake. Psilocybin altered functional connectivity in bilateral frontal, bilateral occipital, and right and left fronto-occipital regions. The subject's pulse rate also showed non-random variations possibly related to the substance. This first fNIRS pilot study demonstrates the technique can detect psilocybin-induced resting-state connectivity changes, though results are from a single participant and require replication with larger samples and improved setups.
Zurich Open Repository and Archive (University of Zurich)
January 1, 2012
Erich Studerus
6 citations
Psilocybin, a hallucinogenic drug, is generally well tolerated when administered in a controlled clinical or research setting. In pooled data from eight double-blind placebo-controlled studies involving 110 healthy subjects who received 1-4 oral doses (45-315 μg/kg), most described the experience as pleasurable, enriching, and non-threatening. Strong anxiety or dysphoria occurred only at the two highest doses in a small proportion of subjects, resolving with emotional support alone. Mild complaints 24 hours after intake included headache and fatigue. Follow-up interviews 8-16 months later found no flashbacks, prolonged psychosis, or subsequent drug abuse among any subjects.
Zurich Open Repository and Archive (University of Zurich)
January 1, 2012
André Schmidt
Ketamine, an NMDAR antagonist, disrupts mismatch negativity (MMN) event-related potentials in healthy humans, impairing prediction error processing, whereas psilocybin, a 5-HT receptor agonist, does not. Both drugs produce positive-like psychotic symptoms, but only ketamine causes severe cognitive impairments, the degree of which correlates with prediction error processing under placebo. These results indicate that the NMDAR system, not the 5-HT system, is critical for MMN generation and implicit perceptual learning, and that aberrant prediction error signaling contributes to cognitive deficits in psychosis. Assessing MMN may help detect early schizophrenia and evaluate treatments for cognitive symptoms.