The study of single photo emission computed tomography in patients with obsessive-compulsive disorder and those with depressive disorder.

Objective To study single photo emission computed tomography(SPECT) features in patients with obsessive-compulsive disorder(OCD) and those with depressive disorder.Methods 99mTc-ECD brain SPECT imaging was performed in 39 untreated patients with OCD,36 untreated patients with depressive disorder and 39 normal controls.Results The rCBF in prefrontal lobe and pretemporal lobe were higher in OCD than in normal subjects(P0.01).Compared with controls,there were decreases in rCBF in prefrontal lobe,cingulate gyrus and right temporal lobe,parietal lobe,occipital lobe in depressive patients(P0.01 or P0.05).The rCBF in the prefrontal lobe,pretemporal lobe,parietal lobe,cingulated and occipital lobe were higher in OCD group than in depressive patients(P0.01 or P0.05).Conclusions Patients with OCD have high cerebral perfusion in the frontal lobe and temporal lobe,whereas patients with depressive disorder have low cerebral perfusion in the whole cortex.The cerebral perfusion in OCD is different from depressive disorder.Brain SPECT imaging may be useful for differentiating OCD from depressive disorder.