Brain Networks Involved in Depression in Patients with Frontotemporal Dementia and Parkinson's Disease: An...

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Depression is a common neuropsychiatric condition affecting neurodegenerative disorders.
• Frontotemporal dementia (FTD) and Parkinson's disease (PD) share common depressive symptoms despite differing pathologies.
• Understanding the neural basis of depression in these conditions is crucial for targeted interventions.

Purpose of the Study:

• To investigate the brain networks associated with depression in patients with FTD and PD.
• To compare functional connectivity (FC) patterns in depressed FTD/PD patients versus non-depressed patients and healthy controls (HC).
• To identify common neural pathways implicated in depression across different neurocognitive disorders.

Main Methods:

• Fifty participants (17 depressed FTD/PD, 17 non-depressed FTD/PD, 16 HC) were assessed using the Beck Depression Inventory (BDI-II).
• 3T brain magnetic resonance imaging (MRI) with structural and resting-state functional sequences was acquired.
• Seed-to-seed and network-to-network analyses were employed to assess resting-state functional connectivity (FC) differences.

Main Results:

• Depressed FTD/PD patients showed significant hyperconnectivity between the left thalamus and left posterior temporal fusiform cortex compared to HCs.
• Network-to-network analysis revealed hyperconnectivity within the default-mode network, medial prefrontal cortex, and central executive network in depressed patients.
• Replication analyses with independent samples (non-depressed PD and FTD) did not show these FC differences, suggesting a depression-specific pathway.

Conclusions:

• A common depression-related neural pathway, characterized by specific hyperconnectivity patterns, may be implicated in both FTD and PD.
• These findings highlight shared neural mechanisms of depression in distinct neurodegenerative conditions.
• The identified FC patterns could serve as potential biomarkers for depression in FTD and PD.