Nitrous Oxide in the Treatment of Acute Suicidal Ideation

The primary aim of the NITOS study is to investigate the potential rapid antisuicidal effects of N2O in the transdiagnostic treatment of suicidal ideation. On day 1, patients will receive either nitrous oxide (50% N2O balanced with oxygen) or placebo (50% oxygen balanced with air). Seven days after the first inhalation, a second inhalation will be performed. All patients will receive N2O at least once during this trial. While the first inhalation will be double-blind, only the patients but not the raters will be blinded to the second inhalation (day 8). For mechanism of action and prediction, a nested biomarker substudy will employ multimodal techniques including analysis of hair and blood samples, and EEG.

NCT Number	NCT06636357
Lead Sponsor	University of Zurich
Conditions	Suicidality, EEG, Suicidal Ideation, Nitrous Oxide, Biomarkers / Blood, Biomarkers / Hair
Enrollment	85 participants
Start Date	2025-01-13
Primary Completion	2026-09-30 (estimated)
Study Completion	2026-09-30 (estimated)
Updated on ClinicalTrials.gov	2025-01-16