Rising US suicide rates and the increased risk of suicide among persons who visit an
emergency department (ED) for suicidality make the ED an important site for interventions to
prevent suicide. There is no approved treatment for rapid relief of suicidal thoughts
although clinical trials, including ours, show relief of suicidal thoughts within hours of
treatment with inexpensive, generic, sub-anesthetic ketamine. We propose a clinical trial of
intramuscular ketamine in depressed ED patients with high-risk suicidality, which if
successful would support a novel, easy-to-use, scalable intervention for busy emergency
clinicians to implement.