Univariate analyses of associations between these polymorphisms and each specific symptom (nausea, tiredness, depression) are provided in Supplementary Table S4 and there was less likelihood of nausea in carriers of OPRM1 rs1799971 (OR = 0.43 (0.23–0.78), P = 0.004). The gene discussed is OPRM1; the disease is major depressive disorder.