Efficacy and Safety of Intranasal Esketamine for the Rapid Reduction of Symptoms of Depression and Suicidality in Patients at Imminent Risk for Suicide: Results of a Double-Blind, Randomized, Placebo-Controlled Study

Objective: The authors compared the efficacy of standard-of-care treatment plus intranasal esketamine or placebo for rapid reduction of symptoms of major depression, including suicidality, among individuals at imminent suicide risk.

Method: In a double-blind, multicenter, proof-of-concept study, 68 participants were randomly assigned to receive esketamine (84 mg) or placebo twice weekly for 4 weeks, in addition to comprehensive standard-of-care treatment. The primary efficacy endpoint was change in score from baseline to 4 hours after initial dose on the Montgomery-Åsberg Depression Rating Scale (MADRS). Clinician global judgment of suicide risk (from the Suicide Ideation and Behavior Assessment Tool) was also assessed. Secondary endpoints included these measures at 24 hours and double-blind endpoint at day 25.

Results: A significantly greater improvement in MADRS score was observed in the esketamine group compared with the placebo group at 4 hours (least-square mean difference=-5.3, SE=2.10; effect size=0.61) and at ∼24 hours (least-square mean difference=-7.2, SE=2.85; effect size=0.65), but not at day 25 (least-square mean difference=-4.5, SE=3.14; effect size=0.35). Significantly greater improvement was also observed in the esketamine group on the MADRS suicidal thoughts item score at 4 hours (effect size=0.67), but not at 24 hours (effect size=0.35) or at day 25 (effect size=0.29). Between-group reductions in clinician global judgment of suicide risk scores were not statistically different at any time point. The most common adverse events among participants in the esketamine group were nausea, dizziness, dissociation, unpleasant taste, and headache.

Conclusions: These preliminary findings indicate that intranasal esketamine compared with placebo, given in addition to comprehensive standard-of-care treatment, may result in significantly rapid improvement in depressive symptoms, including some measures of suicidal ideation, among depressed patients at imminent risk for suicide.