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N2O for Acute Suicidality and Depression in the ED

Phase 2
Not yet recruiting
Conditions
Major Depressive Disorder
Suicidal Ideation
Treatment Resistant Depression
Interventions
Drug: Nitrous oxide gas for inhalation
Drug: Placebo
Registration Number
NCT05710887
Lead Sponsor
University of Chicago
Brief Summary

Investigators are conducting this double-blind, randomized control trial (RCT), to compare inhaled N2O+ treatment as usual (TAU) versus inhaled placebo+TAU; demonstrating the feasibility and tolerability of the intervention in an emergency department (ED) setting on an acutely suicidal population.

Detailed Description

Past studies have shown that a single dose of ketamine, an NMDA- receptor antagonist has fast and long lasting anti-depressant effect. Although a promising antidepressant and potential anti-suicidal agent, ketamine has very significant side effects including: dissociation, hallucinations, delusional thinking, cognitive impairment, and significant sympathetic nervous system activation.

Nitrous Oxide (N2O) is an NMDA-receptor antagonist with a well-known safety profile used as an analgesic. In a proof-of-concept pilot study, this study's investigator recently demonstrated that N2O also has rapid and marked antidepressant effects in patients with severe treatment-resistant depression (TRD); further sub-analyses showed N2O significantly reduced suicidal ideation (SI). While N2O administration may lead to a reduction in SI, it remains unknown whether severely suicidal patients requiring hospitalization on inpatient psychiatric units would benefit. Investigators hypothesize that N2O will rapidly and safely dampen suicidal thinking with minimal side effects in this population.

Participants will be randomized to receive either N2O or placebo. The study intervention is in tandem with prescribed treatment-as-usual (TAU) by emergency department physicians relating to diagnosis (depression, anxiety, suicidal ideation); which typically involves anxiolytic medications and/or brief psychotherapy administered by care team psychiatry providers.

Study intervention response will be assessed using a self-administered psychiatric diagnostic tool (Computerized Adaptive Testing Mental Health \[CAT-MH\] scores relating to suicide, depression, and anxiety; to determine whether a single 45-minute inhalation of nitrous oxide vs placebo reduces symptoms.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
50
Inclusion Criteria
  • Patients 18-65 years of age, acutely suicidal, presenting to the adult emergency department with documented history of non-psychotic major depressive disorder.
Exclusion Criteria
  • Current psychotic or catatonic symptoms as determined by the hospital care team.
  • Unable or unwilling to give consent for study participation (ability to provide consent will be established by treating physician)
  • Lifetime DSM-V (medical history) diagnoses of schizophrenia, schizoaffective disorders, bipolar disorder, obsessive-compulsive disorder, and panic disorders.
  • Meets current DSM-V substance use disorder of greater than mild severity (other than nicotine or marijuana)
  • Significant pulmonary disease and/or requiring supplemental oxygen.
  • Administration of other NMDA-receptor antagonist treatment (e.g., ketamine) within two weeks of entry into study.
  • Contraindications for N2O (pneumothorax, bowel obstruction, middle ear occlusion, elevated intracranial pressure)
  • Chronic cobalamin and/or folate deficiency treated with folic acid or vitamin B12.
  • Women who are pregnant or breastfeeding
  • Any other factor that in the investigators' judgment may affect patient safety or compliance.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Treatment; Nitrous Oxide 50%Nitrous oxide gas for inhalationA single 45-minute session of inhaled 50% nitrous oxide.
Control; Oxygen-air mixturePlaceboA single 45-minute session of inhaled Oxygen-air mixture
Primary Outcome Measures
NameTimeMethod
Treatment Response Based on Changes in Computerized Adaptive Testing ScoresUp to 24-hours from baseline

Monitor changes in Computerized Adaptive Testing Mental Health (CAT-MH) scores relating to suicide, depression, and anxiety; to determine whether a single 45-minute inhalation of nitrous oxide vs placebo reduces symptoms.

The CAT-MH is a validated self-reporting electronic diagnostic that adaptively selects a small optimal set of items from a large bank of approximately 1,500 items, targeted to individuals current or historical level of severity and likelihood of 'suicide', 'depression', and 'anxiety'.

Generated scores include severity and liklihood percentile:

* suicide = (%) low, intermediate, high

* depression = (%) normal, mild, moderate, severe

* anxiety = (%) normal, mild, moderate, severe

Secondary Outcome Measures
NameTimeMethod
Rapid Treatment ResponseAt 30-minutes to 1-hour from intervention conclusion

Evaluate any acute reduction in symptoms.

Based on changes in CAT-MH scores (suicide, depression, anxiety) at 30-minutes to 1-hour following treatment. Study patients ability to complete self-administered CAT-MH following inhalation may impact time-point.

The CAT-MH is a validated self-reporting electronic diagnostic that adaptively selects a small optimal set of items from a large bank of approximately 1,500 items, targeted to individuals current or historical level of severity and likelihood of 'suicide', 'depression', and 'anxiety'.

Generated scores include severity and liklihood percentile:

* suicide = (%) low, intermediate, high

* depression = (%) normal, mild, moderate, severe

* anxiety = (%) normal, mild, moderate, severe

Sustained Treatment ResponseUp to 24-hours from intervention conclusion

Evaluation of sustained response based on changes in CAT-MH scores at several time-points or until the patient is transferred or discharged from the ED.

The CAT-MH is a validated self-reporting electronic diagnostic that adaptively selects a small optimal set of items from a large bank of approximately 1,500 items, targeted to individuals current or historical level of severity and likelihood of 'suicide', 'depression', and 'anxiety'.

Generated scores include severity and liklihood percentile:

* suicide = (%) low, intermediate, high

* depression = (%) normal, mild, moderate, severe

* anxiety = (%) normal, mild, moderate, severe

Treatment ComplianceIntervention completion, 45-minutes

Evaluate compliance of an acutely suicidal population in an Emergency Department (ED) setting, to complete a single 45-minute inhalation of nitrous oxide vs placebo.

Determined by 'ability', 'inability', or 'refusal' to complete the entire 45-minute inhalation session (nitrous oxide vs placebo).

Treatment Response Correlation to Lifetime Predictors Associated with SuicideUp to 24-hours from baseline

Evaluate if lifetime predictors (e.g., personal/family history of suicide attempts or suicide, history of alcohol dependence, and worst lifetime suicidal ideation) of eventual suicide correlate with the acute reduction in symptom severity following treatment.

Lifetime predictors will be determined by medical and social history, and family history related to mental health.

Symptom reduction is determined by changes in CAT-MH scores, over 24-hours from baseline.

The CAT-MH is a validated self-reporting electronic diagnostic that adaptively selects a small optimal set of items from a large bank of approximately 1,500 items, targeted to individuals current or historical level of severity and likelihood of 'suicide', 'depression', and 'anxiety'.

Generated scores include severity and liklihood percentile:

* suicide = (%) low, intermediate, high

* depression = (%) normal, mild, moderate, severe

* anxiety = (%) normal, mild, moderate, severe

Trial Locations

Locations (1)

University of Chicago Medicine

🇺🇸

Chicago, Illinois, United States

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