Meta-analysis of brain volume changes in obsessive-compulsive disorder

Area of Science:

• Neuroimaging
• Psychiatry
• Radiology

Background:

• Obsessive-compulsive disorder (OCD) research has extensively explored brain structure alterations using neuroimaging.
• Magnetic resonance imaging (MRI) studies have investigated volumetric changes in various brain regions in OCD patients.

Purpose of the Study:

• To provide a comprehensive overview of structural brain alterations in OCD through a meta-analysis of MRI data.
• To identify specific brain regions with altered volumes in individuals with OCD compared to healthy controls.

Main Methods:

• Systematic literature search for MRI studies reporting volumetric measurements in OCD patients and healthy subjects.
• Meta-analysis using standardized mean differences (SMDs) to compare regional brain volumes.
• Meta-regression analysis to investigate the impact of clinical factors on observed volumetric differences.

Main Results:

• No significant volumetric differences were found in the whole brain, intracranial region, gray matter, or prefrontal cortex.
• Reduced volumes were observed in the left anterior cingulate cortex (ACC) and left/right orbitofrontal cortex (OFC) in OCD patients.
• Increased volumes in the left and right thalamus were noted in OCD patients, with severity correlating to thalamic volumes.

Conclusions:

• Structural alterations in cortical and thalamic regions are evident in OCD.
• Changes in thalamocortical pathways may underlie functional disruptions in frontosubcortical circuits characteristic of OCD.