Psilocybin-induced changes in brain network integrity and segregation correlate with plasma psilocin level and psychedelic experience.
Level 4 - case-series / case-control
Uncontrolled mechanistic pharmacokinetic-pharmacodynamic neuroimaging study in healthy volunteers
PubMed 34246868 · doi:10.1016/j.euroneuro.2021.06.001
What was done
Fifteen healthy individuals received a single peroral dose of psilocybin (0.2–0.3 mg/kg). Investigators tracked plasma psilocin levels (PPL), subjective drug intensity (SDI), and resting-state functional connectivity via functional magnetic resonance imaging (fMRI) across a five-hour post-dose window to assess network integrity and segregation.
What was found
The abstract reports directional relationships without numerical statistics (e.g., correlation coefficients or p-values). PPL and SDI correlated negatively with brain network integrity (including the default mode network) and network segregation. Furthermore, the executive control network and dorsal attention network desegregated, increasing functional connectivity with other brain networks as a function of PPL and SDI.
Why it matters
It links circulating psilocin pharmacokinetics and subjective drug intensity directly to the time-course of functional brain network reorganization in humans.
Limits
The sample size is very small (n = 15) and restricted to healthy volunteers. There was no placebo or active comparator control group reported, and the abstract omits quantitative effect sizes and confidence intervals.
Cited by
- supports Psychedelics do not shut down the default mode network, but rather cause dysregulation and irregular activity patterns within it.