Frontostriatal salience network expands as executive networks contract in Obsessive-Compulsive Disorder

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Obsessive-compulsive disorder (OCD) is associated with frontostriatal circuit dysfunction.
• Existing neuroimaging studies show small, inconsistent neural differences in OCD, hindering understanding of mechanisms and directionality.
• Longitudinal studies are lacking, limiting insight into neural mechanisms driving symptom fluctuations in OCD.

Purpose of the Study:

• To investigate neural differences in frontostriatal networks in individuals with OCD using precision functional mapping.
• To explore longitudinal changes in frontostriatal connectivity and their relationship to OCD symptom severity.
• To identify network-level features and dynamic connectivity shifts associated with OCD risk and symptom fluctuations.

Main Methods:

• Precision functional mapping applied to highly sampled individuals with OCD.
• Analysis of longitudinal neuroimaging data collected over several months.
• Identification and quantification of network expansions and contractions within frontostriatal circuits.

Main Results:

• A twofold expansion of the salience network and a concomitant contraction of the frontoparietal network were identified in individuals with OCD.
• Salience network expansion encroached on adjacent executive networks, leading to their contraction.
• Longitudinal analyses revealed frontostriatal connectivity changes that tracked OCD symptom severity.

Conclusions:

• Imbalances in frontostriatal networks, specifically salience and executive network alterations, may underlie core OCD symptoms like excessive attention to internal stimuli and impaired goal-directed control.
• Dynamic frontostriatal connectivity shifts correlate with OCD symptom severity, suggesting a link between neural changes and clinical fluctuations.
• Precision functional mapping offers a model for personalized psychiatry, enabling the identification of individual-level abnormalities for targeted treatment strategies in OCD.