Neurobiological Correlates of Psilocybin Response in Depression.
Level 3 - non-randomized controlled study
Systematic review synthesizing five neuroimaging studies (four open-label and one mixed open-label/RCT)
PubMed 37230065 · doi:10.4088/PCC.22r03419
What was done
A systematic review of five databases (MEDLINE, Embase, APA PsycINFO, Cochrane, and CINAHL) was conducted through June 2022 to identify neuroimaging studies evaluating psilocybin treatment in depressed patients. Five studies met inclusion criteria: four open-label studies and one combined open-label and randomized controlled trial, all using functional magnetic resonance imaging (fMRI). Three studies paired psilocybin with psychotherapy (one in treatment-refractory and two in nonrefractory depression), and two evaluated refractory patients without noted psychotherapy pairing.
What was found
The abstract reports no numerical values, effect sizes, or participant counts. Qualitatively, psilocybin administration was associated with a transient increase in global connectivity across major neural tracts and localized brain activation, which correlated with antidepressant response.
Why it matters
This review aggregates early neuroimaging data to describe functional brain changes—often framed as a neural reset—that may serve as putative neurobiological correlates or predictors of psilocybin's antidepressant effects.
Limits
The evidence base is very small (five studies), and four of the five included studies were open-label designs lacking randomized control groups. Quantitative effect sizes, aggregate patient sample size, and long-term durability of the functional brain changes were not provided in the abstract.