Objective To explore the energy feature of the spontaneous neural activity in depressive patients with diurnal rhythm.Methods Twenty depressive patients with diurnal rhythm,20 depressive patients without diurnal rhythm and 20 gender-,age-,education-matched healthy controls were scanned with 3.0 T MRI Scanner.According to Results of ANOVA,group-wise two sample t-test was completed.The correlation analysis were conducted between ALFF of significant difference brain regions and the score of Hamilton rating scale for depression.Results The brain regions showing significant differences among three groups were located in the right parahippocampal gyrus(MNI:18,-36,-9;K=136),left parietal lobe(MNI:-54,-45,42;K=86),left cerebellum crus(MNI:-84,-60,36;K=86) and right cerebellum crus(MNI:9,-78,-36;K=91)(P<0.05,Alphasim correct).Compared with non-diurnal rhythm group,the diurnal rhythm group showed significantly increased ALFF in the right parahippocampal gyrus.Compared with healthy group,the diurnal rhythm group showed significantly increased ALFF in right parahippocampal gyrus,left parietal lobe,and significantly decreased ALFF in left cerebellum crus 1 and right cerebellum crus 2.Compared with healthy group,the non-diurnal rhythm group showed significantly increased ALFF in left parietal lobe,and significantly decreased ALFF in left cerebellum crus 1 and bilateral cerebellum crus 2.No correlation between ALFF of significant difference brain regions and clinical symptoms was found(P>0.05).Conclusion The diurnal rhythm observed in depression may be associated with aberrant activity of parahippocampal gyrus.

Objective To explore the variations of functional connectivity in depressive episode pa-tients with diurnal rhythm.Methods Totaly 44 patients with depressive episode with diurnal rhythm(rhythm group),58 patients with depressive episode without diurnal rhythm(non-rhythm group)and 56 matched healthy volunteer controls(healthy group)were scanned with 3.0 T MRI Scanner.Functional connectivity (FC)were calculated between suprachiasmatic nucleus(SCN)and whole brain regions.According to results of ANOVA,group-wise two sample t-test was completed.Correlation analysis were conducted between FC of significant difference brain regions and the score of Hamilton rating scale(HAMD-24)for depression.Results The brain regions showing differences among three groups were located in the left medial superior frontal gy-rus(MNI:x=0,y=39,z=51; K=14)and right cerebellum crus 1(MNI:x=39,y=-48,z=-36; K=18) (P<0.05,Alphasim).Compared with non-rhythm group,the FC of rhythm group showed significantly in-creased in the left medial superior frontal gyrus and right triangular inferior frontal gyrus(MNI:x=39,y=27, z=27;K=10)(P<0.05,Alphasim).Compared with healthy group,the FC of non-rhythm group showed sig-nificantly decreased in left medial superior frontal gyrus(P<0.05,Alphasim).Positive correlation was found be-tween FC in left medial superior frontal gyrus and despair score of HAMD-24(r= 0.31,P= 0.041). Conclusion The synergistic increase in SCN and prefrontal activity in patients with depressive episodes with morning heavy night light rhythm which may be involved in the formation mechanism of the diurnal rhythm.