Functional connectivity within the salience network differentiates autogenous- from reactive-type...

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Obsessive-compulsive disorder (OCD) is characterized by clinical heterogeneity.
• Categorizing OCD into homogenous symptom dimensions aids in understanding neurobiological substrates.
• The autogenous-reactive classification model provides a framework for this categorization.

Purpose of the Study:

• To systematically compare regional and network functional alterations between OCD subtypes based on the autogenous-reactive model.
• To elucidate the neurobiological underpinnings of clinical heterogeneity in OCD.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan autogenous-type OCD (OCD-AO), reactive-type OCD (OCD-RO), and healthy controls (HC).
• Amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) were analyzed.
• Functional connectivity (FC) analysis was performed using identified areas of abnormal local spontaneous brain activity as seeds.

Main Results:

• OCD-AO patients exhibited increased ALFF in the left anterior insula (AI) and increased ReHo in the right AI compared to OCD-RO and HC.
• Hyperconnectivity was observed between bilateral AI and the anterior cingulate cortex (ACC) in OCD-AO patients.
• Both OCD subtypes showed prefrontal cortex deficits and stronger FC between bilateral AI and default mode network (DMN) nodes compared to HC.

Conclusions:

• Aberrant functional interaction between the salience network (SN) and the DMN may be a common pathophysiological substrate in OCD.
• Impaired functional coupling within the SN is specific to autogenous-type OCD.
• Findings support the autogenous-reactive classification model and advance understanding of OCD's neurobiological heterogeneity.