A randomized control trial of ketamine in depressed patients and the relationship with inflammatory factors

Abstract

Objective To evaluate the antidepressant effect of ketamine and explore the relationship with the inflammatory factors. Method In a randomized controlled trial, 32 patients with depression were randomized to receive 0.5 mg/kg of ketamine by intravenous infusion via pump in 40 minute duration(16 patients) and normal saline via intravenous infusion (16 patients) as control. The Montgomery-Asberg Depression Rating Scale (MADRS), Hamilton Depression Scale- 17 Items (HAMD17) and Beck Scale for Suicide Ideation-Chinese Version (BSI-CV) were administered at timepoints of 60 minutes prior to infusion, 110 and 230 minutes, 1, 3 and 7 days after infusion. Response was defined as HAMD17 scores reduced by 50%. Remission was defined as overall HAMD17 scores of ≤ 7. The venous blood sample was collected every hour from all patients. The serum interleukin-1β (IL-1β) and interleukin-6 (IL-6) was measured by radioimmunoassay, and tryptophan (TRP) and cynurin (KYN) assayed by high efficiency liquid chromatography (HPLC). The activity of indolamine 2,3-dioxygenase (IDO) was evaluated by KYN/TRP. Results (1) MADRS (F = 41.013,P 0.05). In patients without response to ketamine, infusion of ketamine had no significant effect on serum levels of IL-1β, IL-6 and KYN/TRP (P>0.05). Conclusion Ketamine treatment is associated rapid improvement in depressive symptoms and remission of suicide ideation. Depressive patients with baseline higher levels of serum IL-1β,IL-6 KYN/TRP ratio may be more sensitive to ketamine treatment. Key words: Ketamine; Depressive disorder; Interleukin-1beta; Interleukins; Indoleamine-pyrrole 2,3,-dioxygenase; Inflammatory factors