Relationship between Resting- state Functional Magnetic Resonance Imaging and the Disease Severity in Patients with Depressive Disorder

Objective To assess the resting- state brain activity and establish its relationship with the disease severity in patients with major depressive disorder. Methods The resting- state brain activity in 10 patients with major depressive disorder and 10 control subjects( healthy volunteers) between June and December,2012 at Department of Mental and Psychogica, the Second Hopital of Hebei Medical University was assessed by functional magnetic resonance imaging( fMRI) using the regional homogeneity( ReHo) approach. The correlation between the score of self- rating depression scale( SDS) and ReHo measurement in depressed patients was analyzed. Results Compared with control subjects,patients with depressive disorder exhibited decreased ReHo in right dentate gyrus,right middle occipital gyrus,left cuneus,bilateral middle frontal gyrus,orbital gyri,anterior cingutate gyrus,right supramarginal gyru,and postcentral gyrus. In contrast,increased ReHo was detected in left dorsal caudate putamen,hippocampus,hippocampal gyrus,right dorsal caudate putamen,head of caudate nucleus,anterior limb of internal capsule,hippocampus,left inferior parietal lobule,and left superior frontal gyrus ventral in depressed patients. The SDS score was correlated negatively with ReHo in left anterior cingutate and orbital gyri( r =- 0. 87) and right middle frontal gyrus( r =- 0. 82) but positively with left cuneus( r = 0. 82). Conclusion The regional homogeneity assed by fMRI is decreased in the cortex of the brain but increased in the limbic system and basal ganglia in patients with depressive disorder. The level of activity in left anterior cingutate,middle frontal gyrus,left superior occipital gyrus and cuneu is correlated with the severity of depression.