The relationship between major depressive disorder and dementia: A bidirectional two-sample Mendelian randomization...

Area of Science:

• Neuroscience
• Psychiatry
• Genetics

Background:

• Major depressive disorder (MDD) and dementia are prevalent neurological and psychiatric conditions.
• The causal relationship between MDD and dementia remains unclear.
• Investigating this link is crucial for understanding disease mechanisms and prevention.

Purpose of the Study:

• To investigate the potential bidirectional causal relationship between MDD and various dementia subtypes.
• To utilize genome-wide association study (GWAS) data for robust genetic analysis.
• To explore genetic links in European populations.

Main Methods:

• Bidirectional two-sample Mendelian randomization (MR) analysis.
• Utilized GWAS summary statistics for MDD and dementia subtypes (AD, FTD, DLB, PDD, VaD).
• Performed correlation sensitivity analyses to ensure result validity.

Main Results:

• MDD was identified as a potential risk factor for vascular dementia (VaD) (OR, 2.131; P=0.006).
• No significant causal link was found between MDD and Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, or Parkinson's disease with dementia.
• Reverse MR analyses showed no dementia subtype as a risk factor for MDD.

Conclusions:

• MDD may be a significant risk factor for developing VaD.
• No evidence suggests dementia subtypes increase the risk of MDD.
• Findings highlight a potential pathway for VaD prevention.