Identifying Neural White Matter Differences in Psychosis and Affective Disturbance Using Diffusion Magnetic Resonance Imaging

• Main Author: Burton, Courtney Rebecca
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01.01.2019
• Subjects: Neurosciences; Psychobiology
• ISBN: 9781392471814; 1392471818

Specific mechanisms of pathophysiology have not been fully elucidated in psychosis syndromes, perhaps due in part to considerable overlap in the clinical features used for diagnosis. Currently, psychosis syndromes are diagnosed based on the timing and duration of psychotic and affective features, with little regard for the neurobehavioral differences becoming apparent via modern neuroscience techniques. Such alterations in cognition, brain function, and brain structure have the potential to inform pathophysiology, as they may serve as biomarkers to aid in diagnosis or as neural targets for study of mechanisms and treatments. Given that higher-order cognition and brain function require integration across distributed neural networks, examination of the underlying neural infrastructure is warranted. Investigations of distributed brain circuitry commonly examine the long-range connections provided by white matter–comprised of bundled, myelinated axons–using diffusion-weighted imaging, to index white matter organization in vivo. The present body of work utilizes diffusion-weighted imaging to investigate whether white matter microstructure differs between psychiatric groups, sorted by both clinical (psychotic and affective) and neurobehavioral (cognitive and neurophysiological) domains. These studies incorporate traditional diffusivity metrics and more novel density metrics, to determine whether white matter might distinguish between psychiatric groups and/or domains of illness. The identification of distinct white matter deviations across clinical and neurobehavioral domains may aid in future studies of pathophysiology, which could result in more targeted, domain-specific treatment.