Association between prefrontal N-acetylaspartate and insight in psychotic disorders

Daouia I. Larabi*, Edith Liemburg, Gerdina H.M. Pijnenborg Pijnenborg, Anita Sibeijn-Kuiper, Annerieke E. de Vos, Leonie Bais, Henderikus Knegtering, Branisalava Curcic-Blake, Andre Aleman

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

6 Citations (Scopus)

Abstract

Insight is impaired in most patients with psychosis and has been associated with poorer prognosis. The exact neural basis of impaired insight is still unknown, but it may involve disrupted prefrontal neural connectivity. Numerous studies have indeed found white matter (WM) abnormalities in psychosis. The association between prefrontal WM abnormalities and insight has not been studied yet by means of proton magnetic resonance spectroscopy (H-1-MRS). H-1-MRS can be used to measure N-acetylaspartate (NAA), which is considered to be a marker of neuronal integrity. We measured insight with the Birchwood Insight Scale (BIS) as well as item G12 of the Positive and Negative Syndrome Scale (PANSS) in 88 patients with psychosis. Prefrontal WM concentrations of NAA and ratios of NAA to creatine (Cr) were assessed with H-1-MRS. Nonparametric partial correlational analyses were conducted between NAA concentrations and insight controlling for illness duration, standardized antipsychotic dose, symptom scores, voxel grey matter content and voxel cerebrospinal fluid content. We found a significant correlation between reduced NAA/Cr ratios and poorer insight as measured with the BIS, which remained significant after additional correction for full width at half maximum, signal/noise and age. This is the first study reporting a relationship between lower prefrontal concentrations of a marker of neuronal integrity and impaired insight, providing further evidence that prefrontal pathology may play an important role in impaired insight in psychosis. This may be explained by the involvement of the prefrontal cortex in several executive and metacognitive functions, such as cognitive flexibility and perspective taking. (C) 2016 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)112-118
Number of pages7
JournalSchizophrenia Research
Volume179
DOIs
Publication statusPublished - Jan-2017

Keywords

  • Proton magnetic resonance spectroscopy (H-1-MRS)
  • Neuronal pathology
  • White matter
  • Connectivity
  • Executive functions
  • MAGNETIC-RESONANCE-SPECTROSCOPY
  • WHITE-MATTER
  • 1ST-EPISODE SCHIZOPHRENIA
  • COGNITIVE INSIGHT
  • METABOLITE CONCENTRATIONS
  • NEGATIVE SYMPTOMS
  • CORTEX
  • DYSFUNCTION
  • BRAIN
  • METAANALYSIS

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