Identifying Schizo-Obsessive Comorbidity by Tract-Based Spatial Statistics and Probabilistic Tractography.

Area of Science:

• Neuroscience
• Psychiatry
• Neuroimaging

Background:

• Schizophrenia and obsessive-compulsive disorder (OCD) frequently co-occur, a condition known as schizo-obsessive comorbidity (SOC).
• The underlying neurobiological mechanisms of SOC remain largely unexplored.
• Understanding white matter alterations in SOC is crucial for elucidating its pathophysiology.

Purpose of the Study:

• To investigate specific white matter abnormalities in patients with SOC.
• To explore the relationship between these white matter changes and clinical features.
• To differentiate SOC patients from schizophrenia-only and OCD-only patients based on white matter indices.

Main Methods:

• Utilized Tract-based Spatial Statistics (TBSS) and Probabilistic Tractography for white matter analysis.
• Compared four groups: SOC patients, schizophrenia patients, OCD patients, and healthy controls.
• Employed ANOVA and Support Vector Classification (SVC) to analyze white matter indices and structural connectivity.

Main Results:

• Patients with SOC exhibited decreased fractional anisotropy (FA) and increased radial diffusivity in the right sagittal stratum and left crescent of the fornix/stria terminalis compared to controls.
• Altered structural connection probabilities were observed across multiple brain networks (Default Mode, Subcortical, Attention, Task Control, Visual, Somatosensory) and the cerebellum in the SOC group.
• Support Vector Classification accurately differentiated SOC patients from other groups using FA features with 78% accuracy.

Conclusions:

• Specific white matter abnormalities, particularly in the sagittal stratum and fornix/stria terminalis, characterize schizo-obsessive comorbidity.
• Network connectivity patterns are distinct in SOC patients.
• White matter integrity metrics, especially FA, show potential as biomarkers for identifying SOC.