Changes after behavior therapy among responsive and nonresponsive patients with obsessive-compulsive disorder.

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Neuroimaging suggests behavior therapy (BT) impacts frontal-subcortical circuits in obsessive-compulsive disorder (OCD).
• Previous studies show inconsistent results regarding BT's effects on brain activity in OCD patients.
• Understanding these changes is crucial for refining treatment strategies.

Purpose of the Study:

• To investigate the effects of successful BT on regional cerebral blood flow (rCBF) in treatment-resistant OCD patients using statistical parametric mapping (SPM).
• To identify specific brain regions affected by BT and their correlation with treatment response.
• To explore the relationship between baseline rCBF in the orbitofrontal cortex (OFC) and BT efficacy.

Main Methods:

• Utilized single photon emission computed tomography (SPECT) with 99mTc-ECD to measure rCBF in 45 treatment-resistant OCD patients.
• SPECT scans were performed before and after a 12-week course of BT.
• Analyzed pre- and post-treatment rCBF using SPM, comparing responders and non-responders.

Main Results:

• No significant pre-treatment rCBF differences were found between BT responders and non-responders.
• Post-treatment, responders showed significantly lower rCBF in the left medial prefrontal cortex (Brodmann area 10) and bilateral middle frontal gyri (Brodmann area 10) compared to non-responders.
• Baseline rCBF in the bilateral orbitofrontal cortex (OFC) positively correlated with the reduction in Y-BOCS scores among responders.

Conclusions:

• BT may induce changes in rCBF within the medial and middle frontal cortex in OCD patients.
• The orbitofrontal cortex (OFC) appears to be associated with the response to behavior therapy in OCD.
• These findings support the role of frontal-subcortical circuit modulation in BT for OCD.