Interplay Between Metabolic Alterations, Bipolar Disorders, and White Matter Microstructure

Abstract

The goal of this dissertation was to describe where and to what extent obesity affects brain white matter in the general population and bipolar disorders. We used magnetic resonance imaging derived diffusion tensor imaging to investigate white matter microstructural alterations in the brain. We conducted voxel-based and region of interest meta-analyses, collaborated with the ENIGMA Bipolar Disorder Working Group to perform mega-analyses in large international samples of over 2000 participants, and explored deeper phenotyping through the Halifax Study. Our results show localized obesity associated white matter abnormalities in the general population. We found obesity, obesity related biomarkers, and psychiatric obesogenic medications added to the white matter alterations in bipolar disorder. Overall, this work has deepened our understanding of how obesity impacts the brain. We hope these insights draw attention to the hidden costs of obesity and provide new treatment options for prevention of negative brain, cognitive, and clinical outcomes.