Nitrous Oxide in the Treatment of Acute Suicidal Ideation

Exclusion Criteria

• •Organic, including symptomatic, mental disorders (F00-F09; lifetime diagnosis)
• •Schizophrenia, schizotypal and delusional disorders (F20-F29; lifetime diagnosis)
• •Mental and behavioral disorders due to psychoactive substance use. Nicotine and cannabis will be ignored (F10-F19)
• •Non-medical (i.e., recreational) use of inhalational N2O during the last 12 months
• •Past intolerance or hypersensitivity to N2O
• •Critical illness
• •Severe cardiac disease
• •Pregnancy or breastfeeding
• •Pulmonary hypertension
• •Chronic cobalamin or folate deficiency unless treated with folic acid and/or vitamin B12
• •History or evidence of any other medical or neurological condition that would expose the subject to an undue risk of a significant adverse event as determined by the clinical judgment of the investigator
• •Treatment with ketamine/esketamine during the last 4 weeks
• •Treatment with opioid medications during the last 3 months
• •Treatment with vagus nerve stimulation (VNS) or electroconvulsive therapy (ECT) within the last 3 months
• •Recent (within the last 4 weeks) or current use of benzodiazepines in excess of 5 mg lorazepam or equivalent per day
• •Finally, any other factors that, in the investigator's judgment, would unduly impact patient safety or compliance during the study.