There were no significant differences in levels of CSF IL-6 (MD: 1.10; 95% CI 0.93–1.30; p = 0.276) or IL-8 (MD: 1.05; 95% CI 0.96–1.16; p = 0.294) among patients with depression relative to healthy controls (Fig. 1, Table 2). Here, IL6 is linked to depressive symptom measurement.