Perceptual distortions and delusional thinking following ketamine administration are related to increased pharmacological MRI signal changes in the parietal lobe

J Psychopharmacol. 2015 Sep;29(9):1025-8. doi: 10.1177/0269881115592337. Epub 2015 Jul 6.

Abstract

Ketamine produces effects in healthy humans that resemble the positive, negative and cognitive symptoms of schizophrenia. We investigated the effect of ketamine administration on brain activity as indexed by blood-oxygen-level-dependent (BOLD) signal change response, and its relationship to ketamine-induced subjective changes, including perceptual distortion. Thirteen healthy participants volunteered for the study. All underwent a 15-min functional MRI acquisition with a ketamine infusion commencing after 5 min (approx 0.26 mg/kg over 20s followed by an infusion of approx. 0.42 mg/kg/h). Following the scan, participants self-rated ketamine-induced effects using the Psychotomimetic States Inventory. Ketamine led to widespread cortical and subcortical increases in BOLD response (FWE-corrected p < 0.01). Self-rated perceptual distortions and delusional thoughts correlated with increased BOLD response in the paracentral lobule (FWE-corrected p < 0.01). The findings suggest that BOLD increases in parietal cortices reflect ketamine effects on circuits that contribute to its capacity to produce perceptual alterations and delusional interpretations.

Keywords: BOLD; Ketamine; fMRI; psychosis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Anesthetics, Dissociative / administration & dosage*
  • Delusions / blood
  • Delusions / chemically induced*
  • Humans
  • Ketamine / administration & dosage*
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Oxygen / blood
  • Parietal Lobe / drug effects*
  • Perceptual Distortion / drug effects*
  • Psychoses, Substance-Induced / blood
  • Schizophrenia / blood
  • Schizophrenia / chemically induced
  • Young Adult

Substances

  • Anesthetics, Dissociative
  • Ketamine
  • Oxygen