Clinical Question

In patients at risk of suicide who are admitted to a hospital, does ketamine (Ketalar) reduce suicidal ideation?

Bottom Line

Ketamine can rapidly reduce suicidal ideation and, presumably, the risk of suicide in at-risk patients voluntarily admitted to a hospital. However, based on this small study, ketamine does not seem to reduce the subsequent risk of attempted suicide over the next six weeks. (Level of Evidence = 1b−)

Synopsis

The researchers from seven hospitals in France enrolled 156 adults who were voluntarily admitted to a hospital for suicidal ideation with a score of more than 3 on the Beck scale for suicidal ideation. The patients, who did not have a history of substance use or psychotic disorders, were randomly assigned using concealed allocation to receive two 40-minute ketamine infusions, 0.5 mg per kg, or saline placebo infusions, given 24 hours apart. Using intention-to-treat analysis, remission of suicidal ideation at three days (one day after the treatment) occurred more frequently in patients who received ketamine: 63% vs. 31.6%; number needed to treat = 3.2; 95% CI, 2.2 to 6.6. The onset of remission was fast, within 40 minutes of the first dose. The benefit was greater in those with bipolar disorder (84.6% vs. 28.0%; P < .001) than in those with major depression (42.3% vs. 35.7%; P = .6). Over the six weeks following admission, a similar number of patients attempted suicide in both groups (eight in the ketamine group and six in the placebo group).

Study design: Randomized controlled trial (double-blinded)

Funding source: Government

Allocation: Concealed

Setting: Inpatient (ward only)

Reference: Abbar M, Demattei C, El-Hage W, et al. Ketamine for the acute treatment of severe suicidal ideation: double blind, randomised placebo controlled trial. BMJ. 2022;376:e067194.

Editor's Note: Dr. Shaughnessy is an assistant medical editor for AFP.