White Matter Features Associated With Autistic Traits in Obsessive-Compulsive Disorder

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Obsessive-compulsive disorder (OCD) is a severe psychiatric condition.
• Comorbid autism spectrum disorder (ASD) or autistic traits can negatively impact OCD treatment outcomes.
• Understanding the neurobiological underpinnings of autistic traits in OCD is crucial for improving patient care.

Purpose of the Study:

• To investigate the relationship between autistic traits and white matter microstructure in OCD patients.
• To identify specific white matter tracts affected by autistic traits in OCD.
• To explore potential neurostructural differences in OCD patients with and without comorbid ASD.

Main Methods:

• Diffusion tensor imaging (DTI) and white matter tractography were used in 33 OCD patients.
• Autistic trait severity was assessed using the Autism-Spectrum Quotient (AQ).
• Correlations between AQ scores and DTI parameters (FA, MD, AD, RD) were analyzed in key white matter tracts, controlling for covariates.

Main Results:

• A negative correlation was found between AQ scores and fractional anisotropy (FA) in the left uncinate fasciculus.
• Positive correlations were observed between AQ scores and mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) in the left uncinate fasciculus.
• OCD patients with comorbid ASD showed significantly altered FA, MD, and RD in the left uncinate fasciculus compared to those without ASD, though these findings did not survive multiple comparisons correction.

Conclusions:

• Variations in the white matter microstructure of the left uncinate fasciculus may be associated with autistic traits in OCD patients.
• These findings suggest that altered white matter integrity in the uncinate fasciculus could contribute to the socio-emotional dysfunction seen in ASD and autistic traits within OCD.
• The left uncinate fasciculus is a potential neurobiological marker for understanding autistic traits in the context of OCD.