ABSTRACT
Obsessive-compulsive disorder (OCD) is a common neuropsychiatric illness characterized by intrusive, repetitive thoughts and ritualistic behaviors that cause marked distress. This chapter provides an updated review and analysis of the functional studies in OCD published to date. It reviews studies of brain function using positron emission tomography, single photon emission CT, magnetic resonance (MR) spectroscopy, and functional magnetic resonance imaging. The chapter reviews the functional neuroanatomy of the frontal-subcortical circuits implicated by neuroimaging studies in OCD. It presents a theoretic model of the pathophysiology of OCD that is supported by neuroimaging findings and basic research. Functional neuroimaging studies of OCD have used MR techniques such as MR spectroscopy and fMR imaging.
