Is there any difference in the fractional amplitude of low-frequency fluctuations between first episode major depressive disorder patients and subclinical depressive subjects?

Abstract

Background To explore the differences in the fractional amplitude of low-frequency fluctuations (fALFF) at the whole-brain level between young adults with major depressive disorder (MDD) and those with Subclinical depression (SD). Methods Thirty-nine first-episode MDD patients, 30 SD subjects, and 37 healthy controls (HCs) were recruited. All participants underwent resting-state fMRI (Rs-fMRI) scans on a 3T MR scanner. We used the fALFF to explore spontaneous neuronal activity between groups. Results Significant differences in the fALFF were observed among the three groups. Compared with the HCs, an increased fALFF was found in the left cerebellum in MDD patients. When MDD patients were compared with SD subjects, we observed increased fALFF values in the bilateral fusiform gyrus and decreased fALFF values in the right inferior frontal gyrus, right superior frontal gyrus, right middle frontal gyrus, left cuneus and right precuneus. Compared with the HCs, the SD group demonstrated increased fALFF values in the precuneus. Additionally, a positive correlated was revealed between the fALFF values and Hamilton Anxiety Scale (HAMA)score in the right fusiform gyrus in MDD patients. Moreover, the fALFF value were negatively correlated with the Beck Depression Inventory (BDI) score in the right inferior frontal gyrus and with the age in the left fusiform gyrus in SD subjects. Conclusions Our findings suggest that alterations of cognitive and executive networks, default mode networks and visual recognition circuits may contribute to the different neural mechanisms between MDD and SD in young adult subjects.