Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action.
Level 2 - randomized trial
Controlled clinical trial in humans
PubMed 9875725 · doi:10.1097/00001756-199812010-00024
What was done
Healthy human volunteers were administered psilocybin to evaluate its psychotomimetic effects. Researchers tested whether these effects were modulated by pretreatment with the serotonin-2A antagonist ketanserin, the atypical antipsychotic risperidone, or the dopamine antagonist haloperidol.
What was found
The abstract reports no numerical values, sample sizes, or test statistics. It reports that ketanserin and risperidone dose-dependently blocked the psychotomimetic effects of psilocybin, whereas haloperidol increased these effects.
Why it matters
The findings provide early human evidence that psilocybin-induced psychosis is driven by serotonin-2A receptor activation rather than dopamine stimulation, informing the understanding of psychedelic mechanisms and antipsychotic drug action.
Limits
The abstract provides no sample size, participant characteristics, exact drug dosages, or quantitative outcome measures. In addition, an acute model of drug-induced psychosis in healthy volunteers may not fully replicate the chronic pathophysiology of schizophrenia.
Cited by
- supports Psilocybin and classic hallucinogens bind to serotonin 5-HT2A and 5-HT2C receptors, with primary behavioral effects mediated through the 5-HT2A receptor.