Explore functional brain changes in bipolar disorder: A whole brain ALE meta-analysis

Background: Previous functional magnetic resonance imaging (fMRI) studies showed inconsistent results for comparison between bipolar disorder (BD) and healthy controls (HC). Methods: An anatomic likelihood estimation (ALE) meta-analysis was used to explore the key regions of brain pathology in BD with different current mood states. Results: Depressed BD patients showed reduced regional homogeneity (ReHo) in the left claustrum and the left middle frontal gyrus (MFG), compared to HC. BD patients with mixed mood status showed decreased fractional amplitude of low frequency fluctuations (fALFF) in the right cerebellar tonsil, the bilateral MFG and the right superior frontal gyrus, compared to HC. Additionally, BD patients with mixed mood status showed increased fALFF in the right inferior occipital gyrus, the right culmen and the left lentiform nucleus, compared to HC. BD patients with mixed mood status showed decreased functional connectivity (FC) in the bilateral cerebellar tonsil, compared to HC. Conclusion: In the present study, key regions undergoing functional deficits in BD patients with different current mood states were obtained with the ALE meta-analysis. In addition, deficits in these regions in fMRI studies might work as biomarkers for early diagnosis of BD.