After adjusting for potential confounders, such as BMI and smoking, and correcting for multiple testing, four proteins remained significantly associated with depression: fibroblast growth factor 21 (FGF21), FGF19, Interleukin-6 (IL-6) and Interleukin-20 receptor subunit alpha (IL-20RA). Here, IL20RA is linked to depressive symptom measurement.