EXAMINING THE HIGH INCIDENCE OF DEPRESSION IN MULTIPLE SCLEROSIS THROUGH LOCAL AND GLOBAL STRUCTURAL NETWORK PERSPECTIVES
Restricted (Penn State Only)
- Author:
- Roman, Cristina Flores-almeida
- Graduate Program:
- Psychology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 05, 2019
- Committee Members:
- Peter A. Arnett, Dissertation Advisor/Co-Advisor
Peter Arnett, Committee Chair/Co-Chair
Jose Angel Soto, Committee Member
Kathryn Suzanne Scherf, Committee Member
Chaleece Wyatt Sandberg, Outside Member
Michael Nelson Hallquist, Committee Member - Keywords:
- multiple sclerosis
structural connectivity
depression
connectometry
graph theory - Abstract:
- Multiple sclerosis (MS) is a neurological disease characterized by lesion-induced white matter deterioration. In addition to the neurological sequelae of the disease, individuals with MS also experience a higher incidence of depression compared to the general population. For a time, it was thought that the common consequences of the disorder- fatigue, physical disability, cognitive dysfunction, and pain- contributed to the large incidence of depression in MS; however, research linking depression to these common outcomes has been inconsistent or relatively weak. White matter damage has been identified as a distal cause of depression in MS, but how white matter damage contributes to depression in this patient group, especially by way of structural networks, is still not well understood (i.e., significant paucity of studies). As such, the primary aim of the proposed study is to assess structural network patterns in individuals with MS and depression (MS+Depression) as compared to two comparison groups (MS-Depression & Depression-MS) in order to identify the specific structural network patterns that contribute to and differentiate depression in MS. Study 1 used a novel approach called connectometry to quantify the local connectome of white matter tracts in relation to depression diagnosis and severity in MS+Depression versus comparison groups, while Study 2 utilized graph theory to examine both local and global structural connectivity networks in relation to depression in the same groups. Findings point to aberrant structural connectivity patterns (i.e., decreased and increased structural connectivity), particularly at the local level, in individuals with MS+Depression and Depression-MS, although connectivity patterns specific to MS+Depression were identified. These results support previous studies claiming MS-specific damage contributes to a “disconnection syndrome” and depression.