Cortical thickness and white matter integrity abnormalities in obsessive-compulsive disorder: A combined multimodal...

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Cerebral morphological abnormalities are implicated in the pathogenesis of obsessive-compulsive disorder (OCD).
• Multimodal imaging strategies are needed to investigate alterations in cortical morphometry and white matter (WM) integrity in OCD.
• Previous studies have not comprehensively evaluated cortical thickness, volume, and WM integrity in OCD patients.

Purpose of the Study:

• To comprehensively evaluate cortical thickness, cortical and subcortical volume, and WM integrity in OCD patients using multimodal neuroimaging.
• To investigate the relationship between structural brain alterations and clinical symptom severity in OCD.
• To explore the potential influence of medication on observed structural changes.

Main Methods:

• Acquired magnetic resonance imaging (MRI) scans from 52 OCD patients and 46 healthy controls (HCs).
• Utilized surface-based morphometry (SBM) for cortical thickness and volume analysis.
• Employed diffusion tensor imaging (DTI) with tract-based spatial statistics (TBSS) to assess white matter integrity (fractional anisotropy and mean diffusivity).

Main Results:

• OCD patients showed reduced cortical thickness in the right posterior cingulate cortex (PCC) compared to controls.
• Significantly decreased fractional anisotropy (FA) values were observed in the genu and body of the corpus callosum (CC) in OCD patients.
• In medication-naïve patients, higher Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores (total and obsession) negatively correlated with right PCC cortical thickness.

Conclusions:

• OCD is associated with symptom-related cortical thinning in the right PCC and altered WM integrity in the genu and body of the CC.
• Medication may alleviate cortical thickness alterations but not white matter integrity changes.
• Multimodal neuroimaging provides a comprehensive perspective for understanding the pathological mechanisms of OCD.