White matter structural alterations in pediatric obsessive-compulsive disorder: relation to symptom dimensions

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Obsessive-compulsive disorder (OCD) is a debilitating neuropsychiatric condition affecting children and adolescents.
• Understanding the neurobiological underpinnings of pediatric OCD is crucial for developing targeted interventions.

Purpose of the Study:

• To identify gray matter (GM) and white matter (WM) volume differences in pediatric OCD patients compared to healthy controls.
• To investigate the relationship between WM/GM volume abnormalities and OCD symptom severity.
• To explore if symptom dimensions explain observed brain volume variations.

Main Methods:

• 62 pediatric OCD patients and 46 healthy controls underwent magnetic resonance imaging (MRI).
• Optimized voxel-based morphometry (VBM) was used to analyze 3D T1-weighted MRI scans.
• Psychopathological scales assessed symptom severity and dimensions.

Main Results:

• OCD patients showed significantly lower WM volume in left dorsolateral and cingulate regions (superior/middle frontal gyri, anterior cingulate gyrus).
• No significant correlation was found between WM volume and overall OCD symptom severity.
• The 'harm/checking' OCD dimension showed a trend towards reduced WM volume in the right superior temporal gyrus and insula.

Conclusions:

• Abnormalities in prefrontal cortex, anterior cingulate cortex, temporal, and limbic regions are implicated in OCD pathophysiology.
• Regional brain volume variations in OCD may be associated with specific symptom dimensions, suggesting clinical heterogeneity.