Ketamine for Depression, 6: Effects on Suicidal Ideation and Possible Use as Crisis Intervention in Patients at Suicide Risk.

A growing body of literature suggests that ketamine, administered in subanesthetic doses, has early-onset antidepressant action in patients with severe and even treatment-refractory depression. Many case reports, open-label studies, and randomized controlled trials (RCTs) suggest that ketamine may have dramatic antisuicidal effects, as well. This article examines the benefits of ketamine in patients with suicidal ideation with particular focus on the findings of recent RCTs and meta-analyses. Important findings are that a single dose of ketamine is associated with antisuicidal benefits that emerge within an hour of administration and persist for up to a week. The benefits are seen in patients with mild as well as clinically significant suicidal ideation. The benefits are observed in midazolam- as well as saline-controlled trials. Effect sizes are medium to large. The improvement in suicidal ideation is only partly explained by improvement in depression severity. It is concluded that there is consistent evidence that a single dose of ketamine has dramatic antisuicidal action that emerges almost immediately after dosing and persists for at least a week. The short- and intermediate-term safety and efficacy of ketamine as a crisis intervention treatment for suicidal patients merit study. Areas that need research are outlined.