Absence of bidirectional causality between primary biliary cholangitis and major depression: A two-sample Mendelian...

Area of Science:

• Genetics
• Hepatology
• Psychiatry

Background:

• Observational studies suggest an association between primary biliary cholangitis (PBC) and major depression (MD).
• The causal relationship between these conditions requires further elucidation.
• Limitations of observational studies necessitate robust analytical approaches.

Purpose of the Study:

• To investigate the potential causal relationship between primary biliary cholangitis (PBC) and major depression (MD).
• To utilize a two-sample Mendelian randomization (MR) analysis for assessing genetic causality.
• To provide a genetically informed perspective on the association between PBC and MD.

Main Methods:

• Two-sample Mendelian randomization (MR) analysis was performed.
• Genome-wide association study (GWAS) data for PBC (8021 cases) and MD (170,756 cases) were utilized.
• Inverse variance weighting, MR-Egger regression, and weighted median approaches were employed to ensure result validity.

Main Results:

• All MR methods indicated no significant causal relationship between major depression (MD) and primary biliary cholangitis (PBC) in either direction.
• No evidence of heterogeneity or horizontal pleiotropy was detected, supporting the robustness of the findings.
• Odds ratios for MD on PBC and PBC on MD did not reach statistical significance.

Conclusions:

• There is no significant genetic evidence supporting a causal link between major depression (MD) and primary biliary cholangitis (PBC).
• Despite the absence of genetic causality, clinical vigilance for depression in PBC patients is advised due to symptom burden.
• Future research should explore broader populations to overcome the limitations of the current European-centric dataset.