Common and Distinct Patterns of Intrinsic Brain Activity Alterations in Major Depression and Bipolar Disorder: Voxel-Based Meta-Analysis

Abstract

Background: Identification of intrinsic brain activity differences and similarities between major depression (MDD) and bipolar disorder (BD) is necessary. However, results have not yet yielded been consistent. Methods: A meta-analysis of whole-brain resting-state functional MRI (rs-fMRI) studies that explored differences in the amplitude of low-frequency fluctuation (ALFF) between patients (including MDD and BD) and healthy controls (HCs) were conducted. Findings: MDD patients displayed increased ALFF in the right superior frontal gyrus (SFG) (including the medial orbitofrontal cortex, medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC)), bilateral insula and decreased ALFF in the bilateral cerebellum, precuneus, and left occipital cortex compared with HCs. BD showed increased ALFF in the bilateral inferior frontal gyrus (IFG), insula, and right SFG, superior temporal gyrus (STG) and decreased ALFF in the bilateral precuneus, left cerebellum, ACC, and STG. In addition, MDD displayed increased ALFF in the left lingual gyrus, left ACC, bilateral precuneus/posterior cingulate gyrus (PCC), and left STG and decreased ALFF in the right insula, right mPFC, right fusiform gyrus, and bilateral striatum relative to BD patients. Conjunction analysis showed increased ALFF in the bilateral insula, mPFC, and decreased ALFF in the left cerebellum in both disorders. Interpretation: MDD and BD show a common pattern of aberrant regional intrinsic brain activity which predominantly includes the insula, mPFC, and cerebellum, while the limbic system may be associated with spatially distinct patterns of brain function, which provide useful insights for understanding the underlying pathophysiology of brain dysfunction in affective disorders, and developing more targeted and efficacious treatment and intervention strategies. Funding Statement: The study was supported by grants from the National Natural Science Foundation of China (81971597, 81671670, 81801685, and 81501456); National Natural Science Foundation of Guangdong Province, China (2018A030310003); Project in Basic Research and Applied Basic Research in General Colleges and Universities of Guangdong, China (2018KZDXM009); Planned Science and Technology Project of Guangzhou, China (20160402007 and 201604020184). Declaration of Interests: The authors declare that they have no conflict of interests. Ethical Approval Statement: Not required.