Study on fractional amplitude of low-frequency fluctuation in male patients with unipolar and bipolar depression

Abstract

Objective To explore the characteristic differences of the fractional amplitude of low-frequency fluctuation (fALFF) feature of the spontaneous neural activity between young male unipolar depression and bipolar depression patients, and determine the biological markers to distinguish the two disorders. Methods Twelve male unipolar depression, 12 bipolar depression patients and 11 age and educated-matched healthy males underwent resting-state functional magnetic resonance imaging scanning at 3.0 Tesla. The whole brain's fALFF were calculated and analyzed. Results The differences of the fALFF of the three groups had significant differences (P<0.01, Alphasim) in the right orbital medial frontal gyrus (6, 33, -9; K=29), the left medial frontal gyrus (-6, 60, 3; K=44) and the left paracentral lobule (-3, -27, 51; K=20). The unipolar depression subjects had significantly higher fALFF compared with healthy controls in the left anterior cingulate gyrus. The bipolar depression subjects had significantly higher fALFF compared with healthy controls in the bilateral medial frontal gyrus and the left middle cingulate gyrus. And the unipolar depression subjects had significantly lower fALFF compared with bipolar depression ones in the right orbital medial frontal gyrus, the right anterior cingulate gyrus and the bilateral medial frontal gyrus(all P<0.05). Conclusions Abnormalities exist in the brain regions in male with unipolar or bipolar depression patients in the resting state, and the abnormal regions are different. Key words: Unipolar depression; Bipolar depression; Male; Resting-state; fALFF