UVM Theses and Dissertations
Format:
Print
Author:
Albaugh, Matthew D.
Dept./Program:
Psychology
Year:
2013
Degree:
PhD
Abstract:
Converging evidence from animal and human studies implicates a network of brain regions principally consisting of cerebral cortical midline areas (e.g., the ventromedial prefrontal cortex, or vmPFC, posterior cingulate, and precuneus) and limbic structures (e.g.the amygdalae) in the pathophysiology ofmood and anxiety symptomatology (Price & Drevets, 2010; Price & Drevets, 2012). In pediatric studies, structural neuroimaging of clinically significant mood and anxiety disorders has typically revealed reduced cortical thickness within prefrontal regions, and decreased white matter integrity in cortico-limbic pathways. Further, functional imaging studies of pediatric hypoactivity within prefrontal areas.
Although myriad-evidence suggests that clinically significant mood and anxiety symptoms are underpinned by dysfunction in the medial prefrontal network, a dearth of research exists regarding the brain structural correlates of subclinical anxiety and depression. Furthermore, it remains unclear the extent to which the structural integrity of cortico-limbic fiber tracts (e.g., the uncinate fasciculi, cingulum bundles) is associated with anxious/depressed behavior among typically developing youths. Studying a large longitudinal sample of healthy youths, we tested the degree to which structure of the medial prefrontal network was related to anxious/depressed symptoms as measured by the Child Behavior Checklist (CBCL).
Given evidence that anxious/depressed symptoms constitute a quantitative trait, we hypothesized that subclinical variation in symptoms would be associated with brain structure in the same regions implicated in clinically significant mood and anxiety. Our results suggest that, among healthy youths, anxious/depressed symptoms are associated with increased amygdalar volume, as well as greater microstructure of cortico-Iimbic pathways serving to interconnect cortical midline structures. For female subjects, there was also evidence of a positive association between hippocampal volume and anxious/depressed symptoms. Our findings also indicate that structural covariance between the amygdalae and dorsal neocortical regions may be qualified by subclinical anxious/depressed symptoms. The implications of these findings are discussed.
Although myriad-evidence suggests that clinically significant mood and anxiety symptoms are underpinned by dysfunction in the medial prefrontal network, a dearth of research exists regarding the brain structural correlates of subclinical anxiety and depression. Furthermore, it remains unclear the extent to which the structural integrity of cortico-limbic fiber tracts (e.g., the uncinate fasciculi, cingulum bundles) is associated with anxious/depressed behavior among typically developing youths. Studying a large longitudinal sample of healthy youths, we tested the degree to which structure of the medial prefrontal network was related to anxious/depressed symptoms as measured by the Child Behavior Checklist (CBCL).
Given evidence that anxious/depressed symptoms constitute a quantitative trait, we hypothesized that subclinical variation in symptoms would be associated with brain structure in the same regions implicated in clinically significant mood and anxiety. Our results suggest that, among healthy youths, anxious/depressed symptoms are associated with increased amygdalar volume, as well as greater microstructure of cortico-Iimbic pathways serving to interconnect cortical midline structures. For female subjects, there was also evidence of a positive association between hippocampal volume and anxious/depressed symptoms. Our findings also indicate that structural covariance between the amygdalae and dorsal neocortical regions may be qualified by subclinical anxious/depressed symptoms. The implications of these findings are discussed.