Nitrous Oxide in the Treatment of Acute Suicidal Ideation

Launched by UNIVERSITY OF ZURICH · Oct 9, 2024

Keywords

ClinConnect Summary

The NITOS study is a clinical trial exploring whether nitrous oxide (commonly known as laughing gas) can quickly help people who are experiencing severe thoughts of suicide. Participants will be given either nitrous oxide mixed with oxygen or a placebo (a substance that looks like the treatment but has no active ingredients) during two sessions spaced a week apart. The study also includes a special analysis of blood and hair samples to understand how nitrous oxide might work in the brain to ease suicidal thoughts.

To participate in this trial, individuals must be between the ages of 18 and 75 and have moderate to severe suicidal thoughts. Key eligibility requirements include being able to provide consent and having a certain level of suicidal ideation measured by specific rating scales. However, people with certain mental health disorders, those currently using other specific treatments, or those with serious medical conditions may not be eligible. Participants can expect to receive support throughout the trial, and all will have the opportunity to try nitrous oxide at least once. This study is currently recruiting, and the findings could help develop new treatments for those struggling with suicidal thoughts.

Gender

ALL

Eligibility criteria

• Inclusion criteria:
• • Ability to give written informed consent
• • Moderate to severe suicidal ideation defined as a score ≥3 on the Montgomery-Asberg Depression Rating Scale (MADRS; Schmidtke et al., 1985) suicide item (item #10) as well as a self-report Beck Scale for Suicide Ideation (BSS; Kliem et al., 2017) items #4 plus #5 score ≥ 2
• • Plasma homocysteine level ≤ 14 µmol/l
• 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.