Nitrous Oxide- Suicidal Ideation

Launched by WASHINGTON UNIVERSITY SCHOOL OF MEDICINE · Nov 7, 2018

Keywords

ClinConnect Summary

This is a research study looking at whether inhaled nitrous oxide (laughing gas) added to standard depression treatment can help reduce suicidal thoughts in adults with unipolar major depression. In a double‑blind, randomized design, eligible participants hospitalized for depression will receive up to four one‑hour nitrous oxide sessions (50% nitrous oxide/50% oxygen) or the same amount of a placebo gas (50% nitrogen/50% oxygen), plus their usual depression care. After the inpatient period, there could be two booster sessions as outpatients. All participants continue their usual therapies, and safety and how well the gas helps with suicidal thoughts are measured throughout the study.

To be eligible, adults aged 18–65 must have a current unipolar major depressive disorder with a relatively high level of symptoms (a depression score of 18 or more) and moderate suicidal thoughts (on a standard scale, a score indicating suicidality). They must not have psychotic disorders, bipolar disorder, severe personality disorders, recent substance abuse (other than nicotine), certain breathing or brain conditions, or pregnancy, among other criteria. The study is being conducted at Washington University in St. Louis, aims to enroll about 50 people, and will compare nitrous oxide to placebo to see if it can safely reduce suicidal thinking and identify factors that might predict who responds best.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • 1. Patients aged 18-65 years old;
• • 2. current diagnosis of unipolar, major depressive disorder (MDD) without psychosis as defined by the Mini-International Neuropsychiatric Interview (MINI) and The Fourth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) DSM-IV determined by clinical interview and by a baseline score of ≥18 on the HDRS-21 (Hamilton Depression Rating Scale 21-item;
• • 3. moderate to severe SI defined as a score ≥3 on the HDRS-21 suicide item (item #3);
• • 4. will have good command of the English language;
• • 5. will have been voluntarily admitted to the inpatient Psychiatric Units at Barnes-Jewish Hospital/Washington University in St. Louis, MO.
• Exclusion Criteria:
• • 1. Lifetime DSM-IV (obtained via MINI) diagnoses of schizophrenia, schizoaffective disorders, bipolar disorder, obsessive-compulsive disorder, evidence of severe personality disorder (e.g., history of recurrent self-mutilation/cutting, significant and recurrent tumultuous relationships), and panic disorders;
• • 2. past 12-month substance abuse/dependence other than nicotine;
• • 3. active psychotic symptoms;
• • 4. significant pulmonary disease and/or requiring supplemental oxygen;
• • 5. administration of other N-Methyl-D-aspartate (NMDA)-receptor antagonist treatment (e.g., ketamine) within two weeks of entry into study;
• • 6. currently receiving electroconvulsive therapy;
• • 7. contraindications for nitrous oxide (pneumothorax, bowel obstruction, middle ear occlusion, elevated intracranial pressure, chronic cobalamin and/or folate deficiency treated with folic acid or vitamin B12);
• • 8. past 12-month history of head trauma;
• • 9. women who are pregnant or breastfeeding;
• • 10. any other factor that in the investigators' judgment may affect patient safety or compliance.