Functional Connectivity Changes Associated With Depression in Dementia With Lewy Bodies

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Depressive symptoms are common in early dementia with Lewy bodies (DLB), affecting over half of patients.
• Understanding the neural underpinnings of depression in DLB is crucial for early diagnosis and treatment.

Purpose of the Study:

• To investigate functional connectivity (FC) alterations associated with depressive symptoms in prodromal to mild DLB.
• To compare FC in depressed versus non-depressed DLB patients and controls.

Main Methods:

• Utilized MRI data from 66 DLB patients and 18 controls.
• Assessed depression using the Mini International Neuropsychiatric Interview.
• Analyzed resting-state functional connectivity (rsFC) with the CONN toolbox via seed-based approaches.

Main Results:

• Found correlations between depression scores and rsFC between fronto-temporal and visual areas in DLB patients (p < 0.05, FDR corrected).
• Depressed DLB patients exhibited decreased rsFC within the salience network (SN) and between the cerebellar (CN) and fronto-parietal networks (FPN).
• Increased rsFC was observed between the default mode network (DMN) and language network (LN) in depressed DLB patients.

Conclusions:

• Depressive symptoms in DLB are associated with specific rsFC changes, particularly involving fronto-temporal and visual regions.
• These connectivity alterations may contribute to emotional dysregulation, negative bias, and rumination in DLB.
• Antidepressant treatment showed associations with altered FC within key brain networks.