For exploration, we selected higher cut-off points for each systemic biomarker to categorize the sample, and we found that the patients with higher TNF-α level (> 3 pg/ml, n = 7) had higher mean CES-D depression score than the rest of the sample (15 vs 10.4, p = 0.03) as shown in figure 1. Here, TNF is linked to major depressive disorder.