This is a randomized (study medication assigned to participants by chance), double-blind (neither the researchers nor the participants know what treatment the participant is receiving), placebo-controlled (an inactive substance which contains no drug) that is compared in a clinical trial with a drug to test if the drug has a real effect), multicenter (when more than one hospital or study team work on a medical research study) study. Study will enroll participants with suicidal ideation who are assessed to be at imminent risk for suicide. The study will consist of a screening evaluation performed within 48 hours prior to the Day 1 intranasal dose immediately followed by a 25-day double-blind treatment phase (Day 1 to 25), and a 65 day follow-up phase (Day 26 to Day 90). The total study duration for each subject will be approximately 13 weeks. Participants' safety will be evaluated throughout the study. If you or a loved one are having thoughts of suicide, please seek immediate medical help. Go to the emergency room or call the National Suicide Prevention Lifeline at 1-800-273-8255.
