In both relaxed and stringent threshold of pQTL, we found no association between genetically predicted reduction in PCSK9 levels and MDD (relaxed-PSMR-multi = 0.410, stringent-PSMR-multi = 0.290), or mood instability (relaxed-PSMR-multi = 0.004, stringent-PSMR-multi = 0.07) in either of the sets. The gene discussed is PCSK9; the disease is major depressive disorder.