Figure 1.
Differences in inflammatory cytokines in TRD patients before and after treatment with ketamine. (a–d) When compared to healthy controls (HC) treatment-resistant depression (TRD) patients exhibited significantly elevated levels of interleukin (IL)-6 (P=0.004), but not other inflammatory markers. (e) Levels of IL-6 and IL-1α significantly decrease in the serum of patients 4 h after treatment with 0.5 mg kg−1 intravenous ketamine—P<0.05 for both. (f) Twenty-four hours after ketamine infusion, the levels of all inflammatory cytokines were no longer significantly different from baseline levels (*P<0.05; **P<0.01; error bars represent s.e.m.).