CXCL8 and major depressive disorder: In the MDD patients’ subgroup, IL-8 and TNF-alpha positively correlated with the reward-dependence (RD) dimension (R = 0.40, p = 0.008 and R = 0.50, p < 0.001, respectively), and attachment (RD2) (R = 0.44, p = 0.003 and R = 0.53, p < 0.001, respectively).