Altered Brain Function in First-Episode and Recurrent Depression: A Resting-State Functional Magnetic Resonance Imaging Study

Abstract

BackgroundStudies on differences in brain function activity between the first depressive episode (FDE) and recurrent depressive episodes (RDE) are scarce. In this study, we used regional homogeneity (ReHo) and amplitude of low-frequency fluctuations (ALFF) as indices of abnormal brain function activity. We aimed to determine the differences in these indices between patients with FDE and those with RDE, and to investigate the correlation between areas of abnormal brain function and clinical symptoms.MethodsA total of 29 patients with RDE, 28 patients with FDE, and 29 healthy controls (HCs) who underwent resting-state functional magnetic resonance imaging were included in this study. The ReHo and ALFF measurements were used for image analysis and further analysis of the correlation between different brain regions and clinical symptoms.ResultsAnalysis of variance showed significant differences among the three groups in ReHo and ALFF in the frontal, parietal, temporal, and occipital lobes. ReHo was higher in the right inferior frontal triangular gyrus and lower in the left inferior temporal gyrus in the RDE group than in the FDE group. Meanwhile, ALFF was higher in the right inferior frontal triangular gyrus, left anterior cingulate gyrus, orbital part of the left middle frontal gyrus, orbital part of the left superior frontal gyrus, and right angular gyrus, but was lower in the right lingual gyrus in the RDE group than in the FDE group. ReHo and ALFF were lower in the left angular gyrus in the RDE and FDE groups than in the HC group. Pearson correlation analysis showed a positive correlation between the ReHo and ALFF values in these abnormal areas in the frontal lobe and the severity of depressive symptoms (P < 0.05). Abnormal areas in the temporal and occipital lobes were negatively correlated with the severity of depressive symptoms (P < 0.05).ConclusionThe RDE and FDE groups had abnormal neural function activity in some of the same brain regions. ReHo and ALFF were more widely distributed in different brain regions and had more complex neuropathological mechanisms in the RDE group than in the FDE group, especially in the right inferior frontal triangular gyrus of the frontal lobe.

A Study of Differential Resting-State Brain Functional Activity in Males and Females with Recurrent Depressive Disorder

“…In this study, the male RDE group had reduced ReHo in the left middle frontal gyrus compared with the female RDE group. The left middle frontal gyrus is an important brain region of the CCN and part of the DLPFC, which is closely related to MDD [ 4 , 38 , 39 ]. The left middle frontal gyrus is involved in emotion regulation, attentional memory, and top-down cognitive control [ 40 , 41 ].…”

“…The left middle frontal gyrus is involved in emotion regulation, attentional memory, and top-down cognitive control [ 40 , 41 ]. Previous studies have found abnormal CCN function in patients with RDE [ 4 ]. In addition, the DLPFC is a major target area for the treatment of MDD by using repetitive transcranial magnetic stimulation (rTMS) [ 42 , 43 ].…”

“…Therefore, we hypothesize that there are different emotional memory and cognitive attention patterns in different sexes of RDE patients. Functional abnormalities in the DLPFC have been observed in functional MRI studies of RDE, and functional abnormalities in the DLPFC correlate with the severity of MDD [ 4 ]. In this study, we further found that the ReHo values of the left middle frontal gyrus in the female MDD group were positively correlated with the HAMD-17 scores, which was not found in the male RDE group, suggesting that the left middle frontal gyrus may be an important imaging marker for female RDE patients, and further studies with expanded sample sizes are needed in the future.…”

“…According to the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) classification criteria, MDD can be classified as the first depressive episode (FDE) and recurrent depressive disorder (RDE) [ 3 ]. The FDE is the first episode without antidepressants, while RDE is a relapse after previous remission with antidepressants or other treatments [ 4 ]. In addition, there are differences in the degree of depression, somatic symptoms, and cognitive function between patients with RDE and FDE [ 4 , 5 , 6 , 7 ].…”

“…The FDE is the first episode without antidepressants, while RDE is a relapse after previous remission with antidepressants or other treatments [ 4 ]. In addition, there are differences in the degree of depression, somatic symptoms, and cognitive function between patients with RDE and FDE [ 4 , 5 , 6 , 7 ]. It was found that patients with MDD have an average of 5–9 depressive episodes in their lifetimes, that 60% of MDD patients in remission with treatment have a high risk of relapse, and that the number of relapses in RDE is positively related to the risk of relapse [ 8 , 9 , 10 ].…”