Nitrous Oxide in the Treatment of Acute Suicidal Ideation

Trial statusRecruiting
Trial phasePhase 2
Trial typeInterventional
Biological sexAll
Age18-65
SponsorUniversity of Zurich

About this trial

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.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

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

Disqualifiers

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

Trial design

Design model

Parallel

Treatments tested in this trial

  • 50% N2O plus 50% O2

    Drug

    Inhalation of 50% N2O plus 50% O2 for 45 min

  • Oxygen (O2)

    Drug

    50% O2 plus 50% air for 45 min

Treatment groups

85 Participants
are divided into 2 treatment groups
Group A: 50% nitrous oxide (N2O) plus 50% oxygenExperimental treatment 1 intervention
Group B: 50% oxygen plus 50% airPlacebo comparator 1 intervention

Trial outcomes

Primary outcomes

1

Beck Scale for Suicidal Ideation (BSS)

Change of BSS score between Day 0 and Day 2. Double-blind treatment with either N2O or placebo inhalation on Day 1.

Time frame
Day 0 to Day 2

Secondary outcomes

1

Montgomery-Åsberg Depression Rating Scale (MADRS )

Time frame
Day 0 to Day 2
2

EEG changes associated with N2O / placebo inhalation

EEG will be performed before, during, and after inhalation

Time frame
Day 1
3

Suicide Visual Analog Scale (S-VAS)

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.

Time frame
Day 1
4

Perceived Burdensomeness Visual Analog Scale (PB-VAS)

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.

Time frame
Day 1

Other outcomes

Sponsors and contacts

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