Negative symptoms are associated with modularity and thalamic connectivity in schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Negative symptoms in schizophrenia, including avolition and anhedonia, significantly impair long-term functioning.
• Limited treatment options and poorly understood neurobiological mechanisms highlight the need for further research.

Purpose of the Study:

• To investigate white-matter network topology differences in schizophrenia patients compared to controls.
• To explore the association between network properties and negative symptoms or cognitive deficits.

Main Methods:

• Diffusion-weighted magnetic resonance imaging (DW-MRI) scans were acquired from 64 schizophrenia patients and 35 healthy controls.
• Graph analytical methods were employed to analyze global and regional network properties, including modularity, clustering coefficient, characteristic path length, and rich club organization.

Main Results:

• Schizophrenia patients displayed higher modularity, clustering coefficient, and characteristic path length, with lower rich connections, indicating impaired global integration.
• Reduced nodal degree was observed in the left thalamus and left putamen in the schizophrenia group.
• Higher modularity correlated with increased negative symptoms, but not cognitive deficits, suggesting specificity to negative symptomology.

Conclusions:

• Alterations in white-matter network topology, particularly increased modularity, are associated with negative symptoms in schizophrenia.
• The findings provide insights into the neurobiological underpinnings of negative symptoms, potentially guiding future therapeutic strategies.