A Magnetic Resonance Spectroscopy Study on Polarity Subphenotypes in Bipolar Disorder
Georgios D. Argyropoulos,
Foteini Christidi,
Efstratios Karavasilis,
Peter Bede,
Georgios Velonakis,
Anastasia Antoniou,
Ioannis Seimenis,
Nikolaos Kelekis,
Nikolaos Smyrnis,
Olympia Papakonstantinou,
Efstathios Efstathopoulos,
Panagiotis Ferentinos
Affiliations
Georgios D. Argyropoulos
Research Unit of Radiology and Medical Imaging, 2nd Department of Radiology, Attikon General University Hospital, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Foteini Christidi
2nd Department of Psychiatry, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Efstratios Karavasilis
Research Unit of Radiology and Medical Imaging, 2nd Department of Radiology, Attikon General University Hospital, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Peter Bede
Computational Neuroimaging Group, Trinity College Dublin, D08 NHY1 Dublin, Ireland
Georgios Velonakis
Research Unit of Radiology and Medical Imaging, 2nd Department of Radiology, Attikon General University Hospital, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Anastasia Antoniou
2nd Department of Psychiatry, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Ioannis Seimenis
Medical Physics Laboratory, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Nikolaos Kelekis
Research Unit of Radiology and Medical Imaging, 2nd Department of Radiology, Attikon General University Hospital, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Nikolaos Smyrnis
2nd Department of Psychiatry, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Olympia Papakonstantinou
Research Unit of Radiology and Medical Imaging, 2nd Department of Radiology, Attikon General University Hospital, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Efstathios Efstathopoulos
Research Unit of Radiology and Medical Imaging, 2nd Department of Radiology, Attikon General University Hospital, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Panagiotis Ferentinos
2nd Department of Psychiatry, School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
Although magnetic resonance spectroscopy (MRS) has provided in vivo measurements of brain chemical profiles in bipolar disorder (BD), there are no data on clinically and therapeutically important onset polarity (OP) and predominant polarity (PP). We conducted a proton MRS study in BD polarity subphenotypes, focusing on emotion regulation brain regions. Forty-one euthymic BD patients stratified according to OP and PP and sixteen healthy controls (HC) were compared. 1H-MRS spectra of the anterior and posterior cingulate cortex (ACC, PCC), left and right hippocampus (LHIPPO, RHIPPO) were acquired at 3.0T to determine metabolite concentrations. We found significant main effects of OP in ACC mI, mI/tNAA, mI/tCr, mI/tCho, PCC tCho, and RHIPPO tNAA/tCho and tCho/tCr. Although PP had no significant main effects, several medium and large effect sizes emerged. Compared to HC, manic subphenotypes (i.e., manic-OP, manic-PP) showed greater differences in RHIPPO and PCC, whereas depressive suphenotypes (i.e., depressive-OP, depressive-PP) in ACC. Effect sizes were consistent between OP and PP as high intraclass correlation coefficients (ICC) were confirmed. Our findings support the utility of MRS in the study of the neurobiological underpinnings of OP and PP, highlighting that the regional specificity of metabolite changes within the emotion regulation network consistently marks both polarity subphenotypes.
