Aberrant large-scale brain modules in deficit and non-deficit schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Schizophrenia is a complex psychiatric disorder with distinct clinical subtypes.
• Deficit schizophrenia (DS) is characterized by primary negative symptoms, but its neural underpinnings are not fully understood.
• Previous research indicates functional connectome alterations in schizophrenia, yet modular organization differences between DS and non-deficit schizophrenia (NDS) remain unclear.

Purpose of the Study:

• To investigate modular-level alterations in brain functional connectomes of DS patients compared to NDS patients and healthy controls (HC).
• To identify specific network properties differentiating these groups.
• To explore the relationship between network measures and clinical symptoms.

Main Methods:

• Re-analysis of resting-state functional magnetic resonance imaging (fMRI) data from 74 schizophrenia patients (33 DS, 41 NDS) and 40 HC.
• Computation of modular (intramodule, intermodule connectivity) and nodal (Z_i, PC_i) graph theory properties.
• Receiver operating characteristic (ROC) analyses for classification and partial correlations with symptom severity.

Main Results:

• Both DS and NDS groups showed altered intramodule and intermodule connectivity across several brain networks (SN, SMN, VN, DMN, FPN).
• DS patients exhibited weaker SN intramodule connectivity and stronger SMN-FPN/SMN-VN intermodule connectivity compared to NDS.
• Specific nodal alterations were identified in DS, and network measures successfully distinguished the three groups, correlating with negative symptoms and neurocognition.

Conclusions:

• Functional connectome disruptions, particularly in SN, SMN, and VN, differentiate DS and NDS.
• These findings offer insights into the neuropathology of negative symptoms in schizophrenia subtypes.
• Identified network alterations may inform targeted treatments for different schizophrenia subtypes.