Herein, we performed a two-sample Mendelian randomization (MR) analysis to investigate the causal relationship between these factors and delirium.<h4>Methods</h4>GWAS data for delirium were sourced from the FINN10 database; GWAS data for risk factors (protein kinase C-binding protein NELL1, neurotrophin-3, neurotrophin-4, brain-derived neurotrophic factor levels, nerve growth factor, ciliary neurotrophic factor, and glial cell-derived neurotrophic factor levels) were from the IEU Open GWAS. This evidence concerns the gene BDNF and delirium.