Publication
Objectives: Bipolar disorder (BD) is a highly heritable disorder characterized by emotion dysregulation and recurrent oscillations between mood states. Despite the proven efficacy of early interventions, vulnerability markers in high-risk individuals are still lacking. BD patients present structural alterations of the hippocampus, a pivotal hub of emotion regulation networks composed of multiple subregions with different projections. However, the hippocampal dynamic functional connectivity (dFC) in BD remains unclear. We aim to investigate whether the dFC of hippocampal subdivisions differentiates BD patients, offspring of BD patients (BDoff), and healthy controls (HC); and whether it correlates with symptoms differently between these groups. Methods: We studied for the first time the dFC of the hippocampus through a cutting-edge micro-co-activation patterns (mu CAPs) analysis of resting-state functional MRI data of 97 subjects (26 BD, 18 BDoff, 53 HC). mu CAPs allow a data-driven differentiation within the seed region. Results: dFC between the hippocampal body and a somatomotor-mu CAP was lower both in BD patients (p-value(FDR):0.00015) and in BDoff (p-value(FDR):0.020) than in HC. Inversely, dFC between the hippocampal head and a limbic-mu CAP was higher in BD patients than in HC (p-value(FDR): 0.005). Furthermore, the correlations between a frontoparietal-mu CAP and both depression and emotion dysregulation symptoms were significantly higher in BD than HC (p-value(FDR)