An international mega-analysis of psychedelic drug effects on brain circuit function

Area of Science:

• Neuroscience
• Psychopharmacology
• Brain Imaging

Background:

• Psychedelic drugs show therapeutic potential, but their neural mechanisms are unclear.
• Previous resting-state fMRI studies yielded fragmented findings on acute psychedelic effects.
• A need exists for a comprehensive synthesis of psychedelic neuroimaging data.

Purpose of the Study:

• To conduct a mega-analysis integrating multiple datasets on psychedelic drug effects.
• To identify common neural mechanisms across different psychedelic compounds.
• To resolve inconsistencies in previous neuroimaging findings.

Main Methods:

• Meta-analysis of 11 resting-state fMRI datasets across five psychedelic drugs.
• Application of a uniform preprocessing pipeline and Bayesian hierarchical modeling.
• Analysis of functional connectivity alterations in brain networks.

Main Results:

• Identified increased functional connectivity between transmodal and unimodal networks.
• Observed altered coupling between subcortical regions (thalamus, caudate, putamen) and sensorimotor networks.
• Found selective, moderate reductions in within-network connectivity with significant variability.

Conclusions:

• Psychedelics reconfigure large-scale cortical organization and engage subcortical circuitry.
• This study provides a comprehensive map of psychedelic brain action, resolving inconsistencies.
• Offers a benchmark for future psychedelic neuroimaging research.