The functional magnetic resonance imaging-based verbal fluency test in obsessive-compulsive disorder

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Psychiatry

Background:

• Clinical application of functional magnetic resonance imaging (fMRI) for obsessive-compulsive disorder (OCD) is hindered by a lack of standardized tasks and normative data.
• Developing reliable fMRI tasks is crucial for understanding brain function in psychiatric disorders.

Purpose of the Study:

• To investigate brain activation patterns using an fMRI-based verbal fluency test (f-VFT) in individuals with OCD compared to a healthy reference group.
• To assess interindividual variability in brain activation within the OCD group and its correlation with clinical factors.

Main Methods:

• Quantitative evaluation of brain activation using fMRI during an f-VFT in participants with OCD and a normative reference group.
• Comparison of group-level and interindividual activation patterns, focusing on left-hemisphere language regions and the pre-supplementary motor area (pre-SMA).

Main Results:

• Obsessive-compulsive disorder (OCD) participants and controls exhibited similar brain activation in core left-hemisphere language areas.
• Significantly higher interindividual variability in pre-supplementary motor area (pre-SMA) activation was observed in the OCD group compared to the reference group.
• Correlations were found between pre-SMA activation variability and demographic/clinical variables, including perfectionism, in the OCD group.

Conclusions:

• Functional neuroanatomical overlap exists in language processing regions between individuals with OCD and healthy controls.
• Elevated interindividual variability in pre-SMA activation within the OCD group may have implications for clinical fMRI applications and the neurobiology of OCD.
• The f-VFT shows potential for clinical use, but further standardization and understanding of pre-SMA variability are needed.