Relationship between symptom dimensions and white matter alterations in obsessive-compulsive disorder

Area of Science:

• Neuroimaging
• Neuroscience
• Psychiatry

Background:

• Obsessive-compulsive disorder (OCD) is a debilitating mental health condition.
• Understanding the neurobiological underpinnings of OCD symptom dimensions is crucial for targeted treatments.
• White matter alterations have been implicated in various psychiatric disorders, including OCD.

Purpose of the Study:

• To investigate the relationship between the severity of specific OCD symptom dimensions and white matter integrity.
• To identify distinct patterns of white matter alterations associated with different OCD symptom clusters.

Main Methods:

• Diffusion tensor imaging (DTI) was used to assess white matter integrity in 20 OCD patients and 30 healthy controls.
• Tract-based spatial statistics (TBSS) and region-of-interest (ROI) analyses were performed.
• Correlations between OCD symptom dimensions (Obsessive-Compulsive Inventory-Revised) and DTI measures (FA, AD, RD, MD) were examined.

Main Results:

• No significant group differences in fractional anisotropy (FA) or whole-brain correlations between symptom severity and FA were observed.
• ROI analysis revealed specific correlations: checking severity with left inferior frontal/middle temporal white matter (FA), ordering severity with right precuneus (FA, RD).
• Obsessing severity correlated with right supramarginal gyrus (AD, MD), and hoarding severity with right insular gyrus (AD).

Conclusions:

• The study supports the hypothesis that different OCD symptom dimensions are associated with distinct patterns of white matter alterations.
• These findings highlight the neuroanatomical heterogeneity of OCD based on symptom dimensions.
• This research contributes to understanding the neural basis of OCD symptom heterogeneity.