CXCL8 and post-traumatic stress disorder: After adjusting for body mass index, number of TBIs, Combat Exposure Scale score, and time since last injury, the authors found that, compared to TBI participants without symptoms of PTSD, those with PTSD symptoms had higher levels of IL-6, as well as elevated IL-8, IL-10 and TNF-α, with moderate to large effect sizes reported for all four markers (IL-6: d = 0.64, 95% CI: 0.27, 1.00; IL-8: d = 0.77, 95% CI: 0.40, 1.14; IL-10: d = 0.47, 95% CI: 0.11, 0.83; TNFα: d = 1.16, 95% CI: 0.78, 1.54).