Esketamine vs ECT for Acute Suicidality

The experimental group will receive intravenous esketamine hydrochloride. Participants will be asked to fast for 8 hours prior to administration. On treatment days, esketamine will be administered at a dose of 0.2 mg/kg, diluted in 0.9% sodium chloride solution. The infusion rate will be controlled with an infusion pump or syringe pump to ensure a minimum administration duration of 40 minutes. Treatment will be administered three times per week (the recommended interval between sessions is 1 to 2 days, adjustable based on clinical judgment) for two consecutive weeks, totaling six sessions. For participants demonstrating intolerance to either the dose of 0.2 mg/kg or the six-session regimen, investigators could modify the treatment protocol based on efficacy and safety assessments.

The control group will receive ECT. Prior to each session, participants will undergo safety evaluations and concomitant medication adjustments. Following an 8-hour fast and bladder evacuation, other preoperative preparations include intravenous administration of anticholinergic agents, short-acting anesthetics, and muscle relaxants. Electrodes will be placed unilaterally on the non-dominant hemisphere, with the seizure threshold determined via titration. The treatment will be administered three times per week (the recommended interval between sessions is 1 to 2 days, adjustable based on clinical judgment) for two consecutive weeks (six sessions in total). The protocol permitted regimen modifications for participants unable to tolerate the full course, based on efficacy and safety assessments.