OCD has been hypothesized to involve difficulty inhibiting thoughts and behaviors. Prior research has suggested that the brain’s frontal-striatal-thalamic-cortical (FSTC) circuitry plays an important role in regulating behavior, including inhibitory control.
This study by Dr. Roth and his team used functional magnetic resonance imaging (fMRI), a brain imaging technique, to evaluate the activity of FSTC circuitry in 12 adults with OCD and 14 healthy comparison subjects, during performance of a visual go-no/go task assessing response inhibition. The team found that adults with OCD had less activation within the CSTC circuit when trying to stop themselves from responding to a specific cue during the task. This suggested that brain regions responsible for inhibiting responses are not functioning as effectively in persons with OCD. Results further suggested that parts of the circuitry, including the orbitofrontal cortex and thalamus, might play a role in the severity and suppression of OCD symptoms. This was the first study that used fMRI to explore inhibitory control in OCD.
Roth, R.M., Saykin, A.J., Flashman, L.A., Pixley, H.S., & West, J.D. (2007). Event-related fMRI of response inhibition in obsessive-compulsive disorder. Biological Psychiatry, 62, 901-909. doi:10.1016/j.biopsych.2006.12.007