Default mode network subsystem alterations in obsessive–compulsive disorder

Summary & key facts

Researchers used resting brain scans to compare 46 people with obsessive-compulsive disorder and 46 people without. They looked at the default mode network, a group of brain areas that are active when you rest and think about yourself. People with OCD had weaker connections inside a part of that network involved in self-focused thinking, and stronger connections between that self-part and brain systems that detect important events and control attention. These differences stayed present after the researchers took into account medication use and past mood disorders, and they suggest scientists should study how these brain systems interact over time in OCD.

Key facts:

• The study compared resting brain scans from 46 people with obsessive-compulsive disorder and 46 people without the condition.
• The researchers focused on the default mode network, which is a set of brain areas active when people rest or reflect about themselves.
• People with OCD showed reduced connectivity inside the dorsal medial prefrontal cortex 'self' subsystem, a part of the default mode network linked to self-focused thinking.
• People with OCD also showed greater connectivity between that self subsystem and networks that detect important events and guide attention, often called the salience and attention networks.
• These connectivity differences remained after the researchers accounted for whether people were taking psychiatric medication and for any lifetime history of mood disorders, so those factors did not explain the findings.
• The authors say the results point to changes in brain systems tied to self-related thinking in OCD and highlight the need to study how this subsystem interacts with other large brain networks over time.

Abstract

BACKGROUND: Although neurobiological models of obsessive-compulsive disorder (OCD) traditionally emphasise the central role of corticostriatal brain regions, studies of default mode network integrity have garnered increasing interest, but have produced conflicting results. AIMS: To resolve these discrepant findings by examining the integrity of default mode network subsystems in OCD. METHOD: Comparison of seed-based resting-state functional connectivity of 11 default mode network components between 46 patients with OCD and 46 controls using functional magnetic resonance imaging. RESULTS: Significantly reduced connectivity within the dorsal medial prefrontal cortex self subsystem was identified in the OCD group, and remained significant after controlling for medication status and life-time history of affective disorders. Further, greater connectivity between the self subsystem and salience and attention networks was observed. CONCLUSIONS: Results indicate that people with OCD show abnormalities in a neural system previously associated with self-referential processing in healthy individuals, and suggest the need for examination of dynamic interactions between this default mode network subsystem and other large-scale networks in this disorder.

Topics

Functional Brain Connectivity Studies Neurotransmitter Receptor Influence on Behavior Obsessive-Compulsive Spectrum Disorders

Categories

Clinical Psychology Psychology Social Sciences

Tags

Clinical psychology Cognition Default mode network Functional connectivity Functional magnetic resonance imaging Neuroscience Obsessive compulsive Prefrontal cortex Psychology Salience (neuroscience) Task-positive network

Conditions & symptoms

Obsessive-Compulsive Disorder