In plasma, basic fibroblast growth factor (bFGF, p = 0.041), interleukin-7 (IL-7) (p = 0.046), IL-8 (p = 0.014), IL-17b (p = 0.021), macrophage-derived chemokine (MDC, p < 0.001), and thymus and activation regulated chemokine (TARC, p = 0.031) were elevated in the MDD group compared to the nonMDD group. Here, IL17B is linked to major depressive disorder.