Regional Cerebellar Volumetrics in Obsessive-Compulsive Disorder: An ENIGMA-OCD Study.

Area of Science:

• Neuroscience
• Neuroimaging
• Psychiatry

Background:

• Cortico-striato-thalamo-cortical (CTSC) circuits are key in obsessive-compulsive disorder (OCD) understanding.
• Emerging evidence suggests cerebellar involvement in OCD, but prior studies had limitations.

Purpose of the Study:

• To investigate cerebellar sub-regional volumes in individuals with OCD compared to healthy controls (HC) across different age groups.
• To identify potential neuroanatomical differences in the cerebellum associated with OCD.

Main Methods:

• Mega-analysis of individual participant data from the ENIGMA-OCD Working Group.
• Utilized structural MRI scans from 1,954 individuals with OCD and 2,091 HC.
• Employed the ACAPULCO pipeline for cerebellar parcellation and ComBat for harmonizing volume measures.

Main Results:

• Adults with OCD showed significantly smaller volumes in the corpus medullare and bilateral lobule VIIb compared to HC.
• No significant cerebellar volume differences were found in pediatric or adolescent samples after FDR correction.
• Medication status significantly moderated cerebellar sub-regional volumes in all age groups.

Conclusions:

• Novel findings implicate specific cerebellar sub-regions in OCD across development.
• Medication status is a key factor influencing cerebellar differences in OCD.
• Further research into the functional significance of these cerebellar findings may provide translational insights for OCD treatment.