Excessive Checking in Obsessive-Compulsive Disorder: Neurochemical Correlates Revealed by 7T Magnetic Resonance...

Area of Science:

• Neuroscience
• Psychiatry
• Neuroimaging

Background:

• Compulsive checking is a core symptom of obsessive-compulsive disorder (OCD).
• The neural underpinnings of compulsive checking are not well understood.
• Existing research suggests cingulostriatal system dysfunction in OCD.

Purpose of the Study:

• To introduce a novel experimental paradigm for measuring excessive checking in OCD.
• To investigate the neurochemical correlates of compulsive checking.
• To explore the relationship between checking behavior and brain activity in OCD.

Main Methods:

• Thirty-one OCD patients and 29 healthy volunteers performed a decision-making task under high uncertainty.
• 7T magnetic resonance spectroscopy was used to assess the glutamate/GABA ratio in specific brain regions.
• Correlations were examined between checking measures, neurochemistry, and subjective ratings of doubt, anxiety, and confidence.

Main Results:

• OCD patients exhibited excessive and dysfunctional checking behavior.
• Excessive checking in OCD was significantly correlated with the glutamate/GABA ratio in the anterior cingulate cortex.
• Checking behavior in OCD correlated negatively with confidence and positively with doubt, anxiety, and compulsivity.

Conclusions:

• An imbalance in excitatory and inhibitory neural activity (glutamate/GABA ratio) in the anterior cingulate cortex is associated with compulsive checking in OCD.
• This study provides a laboratory model for understanding the development of compulsive checking in OCD.
• The findings highlight the anterior cingulate cortex's role in the pathophysiology of OCD-related checking behaviors.