Genetically predicted causal associations between periodontitis and psychiatric disorders

Area of Science:

• Genetics and Public Health
• Psychiatry and Periodontology

Background:

• Periodontitis and psychiatric disorders are significant health concerns with previously observed but unconfirmed associations.
• Existing observational studies show inconsistent links between periodontitis and mental health conditions, necessitating causal investigation.

Purpose of the Study:

• To investigate the potential bidirectional causal relationships between periodontitis and ten common psychiatric disorders.
• To clarify the etiological connection between gum disease and mental health conditions using robust genetic methods.

Main Methods:

• Employed two-sample Mendelian randomization (MR) analyses utilizing genome-wide association study summary statistics.
• Utilized inverse-variance weighted (IVW) method for primary causal effect estimation, supplemented by MR-Egger, weighted median, and weighted mode sensitivity analyses.
• Assessed results for heterogeneity and horizontal pleiotropy to ensure analytical robustness.

Main Results:

• Mendelian randomization analyses did not reveal a causal association between genetically predicted periodontitis and the ten psychiatric disorders.
• Reverse Mendelian randomization analyses also indicated no causal effect of the ten psychiatric disorders on periodontitis.
• Consistent findings across four MR methods, with no significant heterogeneity or pleiotropy detected, support the robustness of the results.

Conclusions:

• The study does not support a bidirectional causal relationship between genetically predicted periodontitis and ten common psychiatric disorders.
• Observed associations in prior studies may be attributed to potential confounding factors, not direct causality.
• Findings may reduce patient anxiety regarding periodontitis and psychiatric disorders, though further research into dental-mental health links is recommended.