Caudate regional cerebral blood flow in obsessive-compulsive disorder, panic disorder and healthy controls on single photon emission computerised tomography.

We compared regional cerebral blood flow (rCBF) in 15 patients with DSM IIIR obsessive-compulsive disorder (OCD), 15 patients with DSM IIIR panic disorder and 15 healthy controls matched for age, sex and hand preference, using uptake of technetium-99m-D,L-hexamethyl-propylene amine oxime (99mTc HMPAO), on single photon emission computerised tomography (SPECT). Caudate rCBF was significantly reduced in OCD patients compared to healthy subjects and panic disorder patients. When four patients were excluded from each group, right caudate rCBF remained significantly lower in OCD patients than in panic disorder patients or healthy subjects. The data suggest functional involvement of the right caudate nucleus is present in OCD.