The additional administration of ketamine clinically significantly (and statistically superior to midazolam) reduces suicidal ideation in depressed patients within 24 hours. It appears that this effect is partially independent of the antidepressant effect of ketamine.
Purpose: Antidepressants are able to curb suicidal ideation and suicidal acts in patients with depression. However, it often takes weeks for antidepressants to achieve this effect. Many antidepressant trials also generally exclude suicidal patients. Although there is evidence that other biological procedures such as electroconvulsive therapy (ECT) or lithium have antisuicidal effects, there is an overall lack of evidence-based psychopharmacological treatment options for suicidal patients with depressive illness. In addition to clear evidence of a rapid antidepressant effect of ketamine, it is as yet unclear whether ketamine can also reduce suicidality in depressed patients in the short term.
PATIENTS AND METHODS: This randomized clinical trial included 80 patients with major depression and existing current suicidality (as measured by a suicidal ideation scale (SSI)). Of these 80 patients, 43 (=54%) also received antidepressant medication. Randomized, one group of patients received a ketamine infusion and the control group received a midazolam infusion. The primary outcome of the study was the score on the Suicidal Ideation Scale (SSI).
Results: Patients in the ketamine group showed a highly significant reduction in suicidality on the SSI compared with the control group 24 hours after infusion, compared with the midazolam group. 55% of patients with ketamine infusion responded compared with 30% of the midazolam group (measured by reduction in SSI scores). The first significant effects of ketamine infusion appeared as early as 230 minutes after administration, and the effect persisted for six weeks after infusion. This results in a “number needed to treat” of 4.0, i.e. four patients have to be treated with one ketamine infusion to reach one responder. In addition to reducing suicidality, ketamine was more effective than midazolam in reducing depressive symptoms. The side effects of ketamine (blood pressure elevation and dissociative symptoms) were within the expected range and were short-term.
Conclusions: This study shows that the additional administration of ketamine is clinically significant (and statistically superior to midazolam) in reducing suicidal ideation in depressed patients within 24 hours. It appears that this effect is partially independent of the antidepressant effect of ketamine.
InFo NEUROLOGY & PSYCHIATRY 2018; 16(5): 44-45.
