Objective: The aim of this exploratory study is to examine the default mode network (DMN) functional connectivity pattern in elderly depressed subjects with and without comorbid anxiety.
Methods: Functional magnetic resonance imaging data were collected for 11 elderly depressed subjects with high comorbid anxiety and eight elderly depressed subjects with low anxiety. We analyzed the resting-connectivity patterns of the posterior cingulate cortex. We compared the DMN activity in the elderly depressed subjects with high versus low comorbid anxiety.
Results: Depressed elderly with high comorbid anxiety had increased functional connectivity in the posterior regions of the DMN and decreased functional connectivity in the anterior regions of the DMN.
Conclusions: Elderly depressed subjects with high anxiety display a dissociative pattern of connectivity in the DMN when compared with elderly depressed subjects with low anxiety. These results suggest a unique biologic signature of the anxiety symptoms in the context of late-life depression.