Journal of International Psychiatry

Objective To investigate the causal relationship between atopic dermatitis and major depressive disorder using two-sample Mendelian randomization. Methods Extract single nucleotide polymorphisms (SNPs) associated with atopic dermatitis from the summary data of a genome-wide association study (GWAS) and select instrumental variables that meet the criteria. Inverse variance weighted, weighted median, and weighted mode method were used to conduct Mendelian randomization analysis. Sensitivity analysis is performed using heterogeneity testing, horizontal pleiotropy testing, and leave-one-out analysis to assess the robustness of the results. Results A total of 18 genetic instrumental variables were identified. Inverse variance weighted method (OR=1.01; 95% CI: 1.00~1.02; P=0.01) and weighted median method (OR=1.01; 95% CI: 1.00~1.02; P=0.01) showed that atopic dermatitis increases the risk of major depressive disorder. Heterogeneity testing indicated no evidence of heterogeneity in the causal association between atopic dermatitis and major depressive disorder(P>0.05). There was no evidence of horizontal pleiotropy for SNPs of atopic dermatitis as exposure with major depressive disorder (P=0.43). Leave-one-out analysis did not reveal any strong single nucleotide polymorphisms that heavily influenced the results. Conclusion Atopic dermatitis increases the risk of major depressive disorder.

Mendelian Randomization study；atopic dermatitis；major depressive disorder；Causal inference