IL1R1 and major depressive disorder: Prospective MR results demonstrated that the key genes IL1R1 (ENSG00000115594, OR = 0.928; 95% CI, 0.865 to 0.995; P = 0.035) and LPO (ENSG00000167419, OR = 0.937; 95% CI, 0.893 to 0.983; P = 0.008) were significantly associated with a decreased risk of depression, suggesting their potential as protective factors against depression development (Figure 3).