Objective: The objective of the study was to investigate the relationship between structural connectivity (SC) and functional connectivity (FC) in the cingulum in bipolar disorder (BD) and its various phases. Method: We combined resting-state functional magnetic resonance imaging and probabilistic tractographic diffusion tensor imaging to investigate FC and SC of the cingulum and its portions, the SC–FC relationship, and their correlations with clinical and neurocognitive measures on sustained attention in manic (n = 21), depressed (n = 20), and euthymic (n = 20) bipolar patients and healthy controls (HC) (n = 42). Results: First, we found decreased FC between the anterior and posterior parts of the cingulum in manic patients when compared to depressed patients and HC. Second, we observed decreased SC of the cingulum bundle, particularly in its anterior part, in manic patients when compared to HC. Finally, alterations in the cingulum FC (but not SC) correlated with clinical severity scores while changes in the cingulum SC (but not FC) were related with neurocognitive deficits in sustained attention in BD. Conclusion: We demonstrate for the first time a reduction in FC and concomitantly in SC of the cingulum in mania, which correlated with psychopathological and neurocognitive parameters, respectively, in BD. This supports the central role of cingulum connectivity specifically in mania.
Bibliographical noteFunding Information:
GN is grateful for financial support from EJLB-CIHR, the Michael Smith Foundation, and CIHR. GN is CRC Tier1 Chair University of Ottawa. MI is grateful for grant support from the Noto Foundation. The authors thank Professor Giovanni Luigi Mancardi for the access to the Magnetic Resonance Research Center of the Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genoa, Genoa, Italy. The authors are also grateful to Ubaldo Fanti for his technical help in imaging acquisitions.
© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
- affective disorders
- bipolar disorder
- magnetic resonance imaging