No bidirectional relationship between depression and periodontitis: A genetic correlation and Mendelian randomization...

Area of Science:

• Genetics
• Psychiatry
• Periodontology

Background:

• Previous research suggested a potential bidirectional link between depression and periodontitis.
• This study aimed to investigate the genetic underpinnings of this relationship.

Purpose of the Study:

• To estimate the genetic correlation between depression and periodontitis.
• To examine the directionality of causation between these two conditions using genetic methods.

Main Methods:

• Utilized summary statistics from large genome-wide association studies (GWAS) of European ancestry.
• Employed linkage disequilibrium score regression (LDSC) for global genetic correlation and ρ-HESS for local genetic correlation.
• Applied Mendelian randomization (MR) techniques, including LHC-MR and CAUSE, to assess bidirectional causation.

Main Results:

• LDSC revealed a weak genetic correlation (r_g = 0.06) between depression and periodontitis, which was not statistically significant (P = 0.619).
• ρ-HESS analysis did not identify specific genetic loci with significant shared genetic covariance.
• MR analyses (LHC-MR, CAUSE, conventional MR) found no evidence for a causal relationship in either direction, with odds ratios close to 1.00.

Conclusions:

• The findings do not support a shared genetic basis or heritability between depression and periodontitis.
• There is no evidence of a causal link from depression to periodontitis or vice versa based on the genetic analyses performed.