Furthermore, to examine the pretreatment predictive factors for IFN-induced depression, we used logistic regression models that included the significant factors by univariate analysis and existing knowledge of risk factors for IFN-induced depression, such as age, gender, type of IFN, period for administration of IFN and a history of depression, as well as the genotypes of 6 SNPs with P<0.05 in univariate analysis (rs17666172, rs6870503, rs1562234, rs1863918, rs10479525, and rs3797590). The gene discussed is IFNA1; the disease is major depressive disorder.