REDUCED CAUDATE-NUCLEUS VOLUME IN OBSESSIVE-COMPULSIVE DISORDER

Background: Current hypotheses about the neuroanatomical structures in volved in obsessive-compulsive disorder (OCD) suggest abnormalities in cortical-striatalthalamic-cortical circuits. This study examined sele cted brain regions within or adjacent to these circuits. Methods: Magn etic resonance imaging scans from 26 patients with OCD and 26 healthy controls were analyzed to determine the volumes of the following struc tures: prefrontal cortex (cortex anterior to the genu of the corpus ca llosum), caudate nucleus, lateral and third ventricles, and whole brai n. Results: Patients with OCD had significantly smaller caudate nucleu s volumes than controls (F[1,48]=9.4, P=.004) but did not differ in pr efrontal cortex size or in volumes of the lateral or third ventricles. Structural volumes were not significantly correlated with the duratio n or severity of OCD symptoms. Conclusion: Our findings provide additi onal evidence for pathological involvement of the caudate in OCD.