Comparative study of single photo emission computed tomography between patients with obsessive-compulsive disorder and depressive disorder

Objective To explore the regional cerebral blood flow(rCBF) characteristics in patients with obsessive-compulsive disorder(OCD) and depressive disorder.Methods 99mTc-ECD brain single photon emission computed tomography(SPECT) imaging was performed in 22 untreated OCD patients,20 untreated depressive disorder patients,and compared with 19 normal controls.Results Comparied to normal controls,the patients with OCD demonstrated significantly higher radioactivity rate(RAR) in bilateral prefrontal lobes and anterior temporal lobes.In OCD,the RARs were 94.4±6.4,99.8±6.6,91.6±6.1,92.6±6.6;and in normal controls,RARs were 88.1±7.3,86.9±8.9,84.0±7.2,83.4±7.2(all P0.01).The depressive patients were demonstrated lower RAR in bilateral prefrontal lobes,cingulate gyrus,occipital lobes and right temporal lobe,parietal lobe.In the depressed,RARs were 79.4±7.1,77.9±6.3,89.5±9.7,89.2±10.2;85.1±6.4,84.3±6.3;75.4±7.5;84.1±7.5;and in normals,RARs were 88.1±7.3,86.9±8.9;97.7±11.2;96.2±8.4,95.4±8.7;83.4±7.2;92.4±9.4(P0.01 or P0.05).Conclusion There are higher rCBF value in frontal lobe and temporal lobe in OCD.There are lower rCBF nearly in the whole cortex in depressive disorder.The cerebral blood perfusion in OCD is different from depressive disorder.Brain SPECT imaging may be the evidence for distinguishing OCD with depressive disorder.