Loading...
Functional brain networks in treatment-resistant schizophrenia
Ganella, Eleni P. Bartholomeusz, Cali F. Seguin, Caio Whittle, Sarah Bousman, Chad Phassouliotis, Christina Everall, Ian Pantelis, Christos Zalesky, Andrew
Ganella, Eleni P.
Bartholomeusz, Cali F.
Seguin, Caio
Whittle, Sarah
Bousman, Chad
Phassouliotis, Christina
Everall, Ian
Pantelis, Christos
Zalesky, Andrew
Abstract
Introduction
Up to 20% of individuals with schizophrenia show minimal or no response to medication and are considered to have ‘treatment-resistant’ schizophrenia (TRS). Unlike early and established schizophrenia, few studies have investigated resting-state functional connectivity (rs-FC) in TRS. Here, we test for disruptions in FC and altered efficiency of functional brain networks in a well-characterized cohort of TRS patients.
Methods
Resting-state functional magnetic resonance imaging was used to investigate functional brain networks in 42 TRS participants prescribed clozapine (30 males, mean age = 41.3(10)) and 42 healthy controls (24 males, mean age = 38.4(10)). Graph analysis was used to characterize between-group differences in local and global efficiency of functional brain network organization as well as the strength of FC.
Results
Global brain FC was reduced in TRS patients (p = 0.0001). Relative to controls, 3.4% of all functional connections showed reduced strength in TRS (p < 0.001), predominantly involving fronto-temporal, fronto-occipital and temporo-occipital connections. Global efficiency was reduced in TRS (p = 0.0015), whereas local efficiency was increased (p = 0.0042).
Conclusions
TRS is associated with widespread reductions in rs-FC and altered network topology. Increased local functional network efficiency coupled with decreased global efficiency suggests that hub-to-hub connections are preferentially affected in TRS. These findings further our understanding of the neurobiological impairments in TRS.
Keywords
Functional connectivity, Treatment-resistant schizophrenia, Network efficiency, FMRI
Date
2017
Type
Journal article
Journal
Schizophrenia Research
Book
Volume
184
Issue
Page Range
73-81
Article Number
ACU Department
Collections
Relation URI
Source URL
Event URL
Open Access Status
License
All rights reserved
File Access
Controlled