Document Detail

Functional connectivity measures after psilocybin inform a novel hypothesis of early psychosis.
MedLine Citation:
PMID:  23044373     Owner:  NLM     Status:  MEDLINE    
Psilocybin is a classic psychedelic and a candidate drug model of psychosis. This study measured the effects of psilocybin on resting-state network and thalamocortical functional connectivity (FC) using functional magnetic resonance imaging (fMRI). Fifteen healthy volunteers received intravenous infusions of psilocybin and placebo in 2 task-free resting-state scans. Primary analyses focused on changes in FC between the default-mode- (DMN) and task-positive network (TPN). Spontaneous activity in the DMN is orthogonal to spontaneous activity in the TPN, and it is well known that these networks support very different functions (ie, the DMN supports introspection, whereas the TPN supports externally focused attention). Here, independent components and seed-based FC analyses revealed increased DMN-TPN FC and so decreased DMN-TPN orthogonality after psilocybin. Increased DMN-TPN FC has been found in psychosis and meditatory states, which share some phenomenological similarities with the psychedelic state. Increased DMN-TPN FC has also been observed in sedation, as has decreased thalamocortical FC, but here we found preserved thalamocortical FC after psilocybin. Thus, we propose that thalamocortical FC may be related to arousal, whereas DMN-TPN FC is related to the separateness of internally and externally focused states. We suggest that this orthogonality is compromised in early psychosis, explaining similarities between its phenomenology and that of the psychedelic state and supporting the utility of psilocybin as a model of early psychosis.
Robin L Carhart-Harris; Robert Leech; David Erritzoe; Tim M Williams; James M Stone; John Evans; David J Sharp; Amanda Feilding; Richard G Wise; David J Nutt
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-10-08
Journal Detail:
Title:  Schizophrenia bulletin     Volume:  39     ISSN:  1745-1701     ISO Abbreviation:  Schizophr Bull     Publication Date:  2013 Nov 
Date Detail:
Created Date:  2013-10-14     Completed Date:  2014-06-23     Revised Date:  2014-11-05    
Medline Journal Info:
Nlm Unique ID:  0236760     Medline TA:  Schizophr Bull     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1343-51     Citation Subset:  IM    
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MeSH Terms
Cerebral Cortex / drug effects,  physiopathology
Cerebrum / drug effects,  physiopathology*
Connectome / instrumentation,  methods*
Hallucinogens / administration & dosage,  adverse effects,  pharmacology*
Nerve Net / drug effects*,  physiopathology
Psilocybine / administration & dosage,  adverse effects,  pharmacology*
Psychoses, Substance-Induced / physiopathology
Psychotic Disorders / physiopathology*
Reproducibility of Results
Thalamus / drug effects,  physiopathology
Young Adult
Reg. No./Substance:
0/Hallucinogens; 2RV7212BP0/Psilocybine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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