Nitrous Oxide in the Treatment of Acute Suicidal Ideation (NITOS)

January 13, 2025 updated by: Sebastian Olbrich, University of Zurich
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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
85

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Switzerland
      • Zürich, Switzerland, 8032
        • Recruiting
        • Psychiatric University Hospital Zurich
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: 50% nitrous oxide (N2O) plus 50% oxygen
Patients will be treated with N20 (50% N2O combined with 50% oxygen) for 45 minutes. Both the study subject and the rater will be blinded to the treatment assignment.
Drug: 50% N2O plus 50% O2
Inhalation of 50% N2O plus 50% O2 for 45 min
Placebo Comparator: 50% oxygen plus 50% air
Here, patients will be treated with 50% oxygen plus air for 45 minutes. Both the study subject and the rater will be blinded to the treatment assignment.
Drug: Oxygen (O2)
50% O2 plus 50% air for 45 min

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Beck Scale for Suicidal Ideation (BSS)
Time Frame: Day 0 to Day 2
Change of BSS score between Day 0 and Day 2. Double-blind treatment with either N2O or placebo inhalation on Day 1.
Day 0 to Day 2

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Montgomery-Åsberg Depression Rating Scale (MADRS )
Time Frame: Day 0 to Day 2
Day 0 to Day 2
EEG changes associated with N2O / placebo inhalation
Time Frame: Day 1
EEG will be performed before, during, and after inhalation
Day 1
Suicide Visual Analog Scale (S-VAS)
Time Frame: Day 1
Briefly, the S-VAS uses the phrase "urge to kill myself". Next to the phrase, the patient sees a line that is anchored on the left with the word "none" and on the right with the word "extreme" . Score ranges from 0 to 100.
Day 1
Perceived Burdensomeness Visual Analog Scale (PB-VAS)
Time Frame: Day 1
The PB-VAS uses the phrase "like a burden". Next to the phrase, the patient sees a line that is anchored on the left with the word "none" and on the right with the word "extreme" . Score ranges from 0 to 100.
Day 1

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Zurich

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 13, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 30, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 6, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 9, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 10, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 25, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 13, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2024-01005

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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