The relationship between major depression and delirium: A two-sample Mendelian randomization analysis.

Area of Science:

• Psychiatry
• Genetics
• Epidemiology

Background:

• Major depression (MD) is a recognized risk factor for delirium.
• Observational studies are limited in establishing a direct causal relationship between MD and delirium.

Purpose of the Study:

• To investigate the potential genetic causal association between major depression and delirium.
• Utilize two-sample Mendelian randomization (MR) to assess causality.

Main Methods:

• Employed two-sample Mendelian randomization (MR) analysis.
• Utilized genome-wide association study (GWAS) summary data for MD (UK Biobank) and delirium (FinnGen Consortium).
• Applied various MR methods including Inverse-variance weighted (IVW), MR Egger, and weighted median, alongside heterogeneity and pleiotropy tests.

Main Results:

• The IVW method indicated that MD is an independent risk factor for delirium (P = 0.013).
• No significant evidence of heterogeneity or horizontal pleiotropy was found, suggesting robust causality.
• Leave-one-out analysis confirmed the stability and reliability of the association.

Conclusions:

• This study provides genetic evidence for a causal association between major depression and delirium.
• The findings support MD as a significant risk factor contributing to the development of delirium.