Resting-State Functional Connectivity Alterations in Obsessive-Compulsive Disorder: Relationships Between...

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Obsessive-compulsive disorder (OCD) is linked to altered resting-state functional connectivity (FC), but findings are inconsistent.
• The Global OCD study aimed to identify consistent OCD-related FC alterations using harmonized data from five international sites.

Purpose of the Study:

• To investigate differences in resting-state functional connectivity (FC) between individuals with OCD and healthy controls (HC).
• To explore associations between FC and clinical characteristics in OCD patients.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was used to estimate FC in 263 unmedicated adults with OCD and 254 HC.
• Analyses included seed-based FC, subnetwork connectivity, global network measures, and network-based statistics (NBS).
• General linear models adjusted for covariates were used to analyze group differences and clinical associations.

Main Results:

• Seed-based analysis revealed weaker FC between the nucleus accumbens and left cerebellum in OCD versus HC.
• Network-based statistics identified widespread hypoconnectivity across 249 regions in individuals with OCD.
• FC in OCD was associated with prior SSRI/SNRI use, comorbid depression, anxiety severity, and specific symptoms like sexual/religious and contamination concerns.

Conclusions:

• Individuals with OCD demonstrate widespread brain hypoconnectivity compared to healthy controls.
• Significant interindividual variability exists within the OCD group, influenced by medication history, comorbidities, and symptom presentation.