Available online 19 October 2022, 111557

MDD patients with long-term remission still have brain dysfunction, although they may not show clinical symptoms.

Regional brain dysfunction may affect whole brain functional activity, and these dysfunctions may also be compensated by other brain regions.

This study was the first to explore whether the abnormal local spontaneous neuronal activities exist in MDD patients with the long-term remission and may disrupt the whole brain functional connectivity. The findings may provide new reasons for MDD relapse.

This study was the first to explore whether abnormal spontaneous neuronal activities exist in patients in the long-term remission stage of major depressive disorder (MDD). We recruited 34 MDD patients (PTs) and 30 sex- and age-matched healthy controls (HCs). Resting-state functional magnetic resonance imaging (rs-fMRI) was employed to scan all subjects’ brain regions, and independent two-sample t-test was used for regional homogeneity (ReHo) and functional connectivity (FC) analysis. Compared with the HCs, the ReHo of PTs increased in the right superior frontal gyrus and left middle frontal gyrus, and decreased in the right anterior and collateral cingulate gyrus, right middle frontal gyrus, right inferior parietal lobule. The cingulate gyrus as a mask showed that FC of the cingulate gyrus with the bilateral lingual gyrus and the right middle temporal gyrus decreased, and FC with the left supper frontal gyrus increased. The correlation analysis revealed no significant correlation between the abnormal ReHo and HAMD-24 scores in PTs. The ReHo of inferior parietal lobule and the duration of remission were positively correlated. We concluded that the spontaneous neuronal activities might be disrupted in MDD patients in the long-term remission stage. Our findings provided new reasons for MDD relapse.

Major depressive disorder

Long-term remission

Resting-state functional magnetic resonance imaging, Regional homogeneity

Functional connectivity

© 2022 The Author(s). Published by Elsevier B.V.