Repository logo
 

Cognitive function in early-phase schizophrenia-spectrum disorder: IQ subtypes, brain volume and immune markers.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Giordano, Annalisa 
Suckling, John 
Barnes, Thomas RE 
Husain, Nusrat 

Abstract

BACKGROUND: Evidence suggests that cognitive subtypes exist in schizophrenia that may reflect different neurobiological trajectories. We aimed to identify whether IQ-derived cognitive subtypes are present in early-phase schizophrenia-spectrum disorder and examine their relationship with brain structure and markers of neuroinflammation. METHOD: 161 patients with recent-onset schizophrenia spectrum disorder (<5 years) were recruited. Estimated premorbid and current IQ were calculated using the Wechsler Test of Adult Reading and a 4-subtest WAIS-III. Cognitive subtypes were identified with k-means clustering. Freesurfer was used to analyse 3.0 T MRI. Blood samples were analysed for hs-CRP, IL-1RA, IL-6 and TNF-α. RESULTS: Three subtypes were identified indicating preserved (PIQ), deteriorated (DIQ) and compromised (CIQ) IQ. Absolute total brain volume was significantly smaller in CIQ compared to PIQ and DIQ, and intracranial volume was smaller in CIQ than PIQ (F(2, 124) = 6.407, p = 0.002) indicative of premorbid smaller brain size in the CIQ group. CIQ had higher levels of hs-CRP than PIQ (F(2, 131) = 5.01, p = 0.008). PIQ showed differentially impaired processing speed and verbal learning compared to IQ-matched healthy controls. CONCLUSIONS: The findings add validity of a neurodevelopmental subtype of schizophrenia identified by comparing estimated premorbid and current IQ and characterised by smaller premorbid brain volume and higher measures of low-grade inflammation (CRP).

Description

Keywords

Cognition, inflammation, neuroimaging, psychosis, schizophrenia-spectrum disorder, subtypes, Adult, Humans, Schizophrenia, C-Reactive Protein, Intelligence, Cognition, Brain, Biomarkers

Journal Title

Psychol Med

Conference Name

Journal ISSN

0033-2917
1469-8978

Volume Title

Publisher

Cambridge University Press (CUP)
Sponsorship
National Institute for Health Research (NIHR) via Comprehensive Local Research Network (CLRN) (10411)