Cortical thickness and low insight into symptoms in enduring schizophrenia.

TitleCortical thickness and low insight into symptoms in enduring schizophrenia.
Publication TypeJournal Article
Year of Publication2016
AuthorsEmami S, Guimond S, M Chakravarty M, Lepage M
JournalSchizophr Res
Volume170
Issue1
Pagination66-72
Date Published2016 Jan
ISSN1573-2509
KeywordsAdult, Awareness, Cerebral Cortex, Female, Health Knowledge, Attitudes, Practice, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Organ Size, Psychiatric Status Rating Scales, Regression Analysis, Schizophrenia, Schizophrenic Psychology, Self-Assessment
Abstract

Poor insight is a common, multidimensional phenomenon in patients with schizophrenia, associated with poorer outcomes and treatment non-adherence. Yet scant research has investigated the neuronal correlates of insight into symptoms (IS), a dimension of insight that may be particularly significant in enduring schizophrenia. Sixty-six patients with enduring schizophrenia (duration >4years) and 33 healthy controls completed MRI scanning and IQ, depression, and anxiety assessments. The Scale to Assess Insight-Expanded (SAI-E) measured insight into patients' four most prominent symptoms and patients were classified into two groups: low IS (0-2; n=33), and high IS (>2; n=33). We evaluated the association between cortical thickness (CT) and insight into symptoms using two methods: (1) a between-patients region-of-interest analysis in the insula, superior temporal gyrus (STG) and frontal lobe; and (2) a whole-brain exploratory regression between patient and controls. Brain regions were segmented using a neuroanatomical atlas and vertex-wise CT analyses were conducted with CIVET, covaried for age and sex. ROI analysis revealed thinner insula cortex in patients with low IS (p<0.05, surviving FDR correction). Patients with low IS also showed significantly thinner right insula, STG, and parahippocampal cortex compared to healthy controls (p<0.05, surviving FDR correction). Regions of observed CT reductions have been hypothesized to subserve self-monitoring, error awareness, and ability to identify hallucinations. Results highlight an important association between right insula abnormalities and impaired IS in schizophrenia. The diverse clinical presentation of patients further suggests an independent relationship between symptomology and insight-related differences in CT that has been previously unexplored in enduring schizophrenia.

DOI10.1016/j.schres.2015.10.016
Alternate JournalSchizophr. Res.
PubMed ID26603467
Grant List / / Canadian Institutes of Health Research / Canada

  • Douglas Hospital
  • Dobell Pavillion
  • Brain imaging centre