Consistent with genetic evidence, neuroimaging research into the neural basis of OCD has highlighted dysfunction within the orbitofrontal cortex (OFC) and striatum, which are connected via dense cortico-striatal glutamatergic projections4. Both at rest and following symptom provocation, OCD subjects show hypermetabolism of glucose in the OFC relative to controls24–27, and increased blood-oxygen-level dependent signals in both OFC and caudate, a subregion of the dorsal striatum28,29. In addition, functional connectivity between OFC and striatum is increased in OCD subjects relative to healthy controls30,31 (though see ref. 32).
