Anti-Suicidal Efficacy of Repeated Ketamine Infusions in Depression with Suicidal Ideation

Abstract

Background: Suicide is a tremendous public health crisis around the world and is demanded urgent intervention. Most people who die by suicide suffer from some forms of mental illness, especially mood disorders. Previous studies found that Ketamine intervention could rapidly reduce suicidal ideation. The current study is aim to assess the anti-suicidal efficacy of repeated ketamine infusions for Chinese depressed suicidal patients. Methods: In the current study, 112 unipolar and bipolar depressive patients with current suicidal ideation received six ketamine infusions during a 12-day period. Hamilton Depression Rating Scale (HAMD) was measured at baseline, 4 hours and 24 hours after each infusion, two-week naturalistically follow-up. Findings: 59 (53.6%) relief of suicidal ideation (HAMD-SI=0) after first infusion and 71 (73.2%) after six infusions. Anti-suicidal response rate in low SI group were higher than high SI group (F1,1401=56.81, p<0.001). Moreover, anti-suicidal response at 24 hours after first infusion was significant predictor of response at 24 hours after sixth infusion (b=2.263, <0.001). At 24 hours after sixth infusion, correlation between changes in suicidal ideation and depression was 0.32 (p=0.001), accounting for 9.0% in the variance of suicidal ideation change. Interpretation: We confirmed that six repeated ketamine infusions were effective in generating a rapid response of suicidal ideation, with a large sample size. Reductions in suicidal thoughts following ketamine infusions were associated with, but partially independent of, the improvement in depression. Registration Number: (ChiCTR-OOC-17012239) Funding Statement: This work was supported by the National Key Research and Development Program of China (grant number 2016YFC0906300), the National Natural Science Foundation of China (grant number 81801343, 81801345), the International Communication Foundation Science and Technology Commission of Shanghai Municipality (grant number: 16410722500) and Guangzhou Municipal Psychiatric Disease Clinical Transformation Laboratory (grant number 201805010009), Key Laboratory for Innovation platform Plan, Science and Technology Program of Guangzhou, China. The funding source had no role in the study design, analysis or interpretation of data or in the preparation of the report or decision to publish. Declaration of Interests: The authors declare no competing financial interests or potential conflicts of interest. MW was previously involved in a clinical trial on ketamine in treatment resistant depression in collaboration with Janssen Pharmaceuticals (trial identifier: DRK3527). This study was unrelated to the current study and MW declares no conflict of interest. Ethics Approval Statement: The study was conducted at the Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital) and approved by local ethics committee.