Improvement in suicidal ideation after ketamine infusion: Relationship to reductions in depression and anxiety

Abstract

Objective: Suicide is a psychiatric emergency. Currently, there are no approved pharmacologic treatments for suicidal ideation. Ketamine is an N-methyl-D-aspartate (NMDA) receptor antagonist that rapidly reduces suicidal ideation as well as depression and anxiety, but the dynamic between these symptoms is not known. The aim of this analysis was to evaluate whether ketamine has an impact on suicidal thoughts, independent of depressive and anxiety symptoms. Methods: 133 patients with treatment-resistant depression (major depressive disorder or bipolar I/II disorder) received a single subanesthetic infusion of ketamine (0.5mg/kg over 40min). Post-hoc correlations and linear mixed models evaluated the relationship between suicidal ideation and depression and anxiety symptoms using the Hamilton Depression Rating Scale (HAMD), Scale for Suicidal Ideation (SSI), Beck Depression Inventory (BDI), and Hamilton Anxiety Rating Scale (HAMA) focusing on 230min post-infusion. Results: At 230min post-infusion, correlations between changes in suicidal ideation and depression ranged from 0.23 to 0.44 (p