Underlying neural mechanisms of depression and dementia
Year: 2015
Type: dissertation
Study design: Observational Study
Abstract: Studies have shown that white matter changes and other neuropathology frequently found in individuals with dementia, also may be related to late-life depression, or "vascular dementia." As these two conditions frequently coexist, the question of whether there is a relationship between these neuropathological changes and depression among individuals with manifest dementia has not been established. The aim of the present study was to examine whether there were neuroanatomical differences evident on the CT scans of individuals with dementia based upon depression onset (no depression versus early-onset versus late-onset) and history of late-life depression (any episode of depression after age 60). We hypothesized that individuals with dementia and late-onset depression and/or late-life depression would be more likely than non-depressed individuals with dementia to exhibit frontal lobe deep white matter, subcortical white matter, and subcortical gray matter hypodensities. We found that compared to individuals with Alzheimer's disease and no depression, individuals with Alzheimer's disease and late-onset depression had a greater number of striatal hypodensities (gray matter hypodensities in the caudate nucleus and lentiform nucleus, which includes the putamen and globis pallidus). In addition, we found that although there were no differences between the non-depressed and late-onset and late-life depression groups with respect to white matter hypodensities, the late-onset depression and late-life depression groups in comparison to the non-depressed group displayed a significantly higher degree of global functional impairment, as well as impairment within the domains of memory, orientation, and in the context of their home activities and hobbies. These findings suggest that late-onset depression may be a process that is distinct from the neurodegenerative changes caused by Alzheimer's disease.
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2246250188