Abstract
Indices of functional connectivity in the default mode network (DMN) are promising neural markers of treatment response in late-life depression. We examined the differences in DMN functional connectivity between treatment-responsive and treatment-resistant depressed older adults. Forty-seven depressed older adults underwent MRI scanning pre- and post-pharmacotherapy. Forty-six never depressed older adults underwent MR scanning as comparison subjects. Treatment response was defined as achieving a Hamilton Depression Rating Scale of 10 or less post-treatment. We analyzed resting state functional connectivity using the posterior cingulate cortex as the seed region-of-interest. The resulting correlation maps were employed to investigate between-group differences. Additionally we examined the association between white matter hyperintensity burden and functional connectivity results. Comparison of pre- and post-treatment scans of depressed participants revealed greater post-treatment functional connectivity in the frontal precentral gyrus. Relative to treatment-responsive participants, treatment-resistant participants had increased functional connectivity in the left striatum. When adjusting for white matter hyperintensity burden, the observed differences lost significance for the PCC-prefrontal functional connectivity, but not for the PCC-striatum functional connectivity. The post-treatment "frontalization" of the DMN connectivity suggests a normalizing effect of antidepressant treatment. Moreover, our study confirms the central role of white matter lesions in disrupting brain functional connectivity.
Original language | English (US) |
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Pages (from-to) | 313-321 |
Number of pages | 9 |
Journal | Psychiatry Research - Neuroimaging |
Volume | 214 |
Issue number | 3 |
DOIs | |
State | Published - Dec 30 2013 |
Externally published | Yes |
Keywords
- Default Mode Network
- Late-life depression
- MRI
- Treatment response
- White matter hyperintensity
ASJC Scopus subject areas
- Neuroscience (miscellaneous)
- Radiology Nuclear Medicine and imaging
- Psychiatry and Mental health