Evidence map›Paper›PMID 38241247›Full record

ArticlePloS one2024

Sustained Mood Improvement with Laughing Gas Exposure (SMILE): Study protocol for a randomized placebo-controlled pilot trial of nitrous oxide for treatment-resistant depression.

Karim S Ladha, Jiwon Lee, Gabriella F Mattina, Janneth Pazmino-Canizares, Duminda N Wijeysundera, Fatemeh Gholamali Nezhad, Kaylyssa Philip, Vanessa K Tassone, Fathima Adamsahib, Venkat Bhat and 1 more

Registry-linked trialOpen access · goldAbstract readClinical Trial Protocol
In one paragraph

Article in PloS one, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04957368 (Sustained Mood Improvement With Laughing Gas Exposure), which is not on this map. Cited by 2 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed, 1 pooled it
2.7field-weighted citation impact, top 11% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT04957368 phase4completednot on this map

Sustained Mood Improvement With Laughing Gas Exposure: A Randomized Controlled Pilot Trial

TypeinterventionalSponsorUnity Health TorontoRan2021 to 2024Enrolled40ConditionsTreatment Resistant Depression, Major Depressive DisorderArmsNitrous Oxide 99 %, Oxygen + Midazolam
3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 1 synthesis or guideline pooled it, 6 citations in OpenAlex.

  1. Pooled it
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors at 1 institution in 1 country.

Karim S LadhaDepartment of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada.
Jiwon LeeDepartment of Anesthesia, St. Michael's Hospital, Toronto, Ontario, Canada.ORCID https://orcid.org/0000-0002-7903-1883
Gabriella F MattinaDepartment of Anesthesia, St. Michael's Hospital, Toronto, Ontario, Canada.
Janneth Pazmino-CanizaresDepartment of Anesthesia, St. Michael's Hospital, Toronto, Ontario, Canada.
Duminda N WijeysunderaDepartment of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada.ORCID https://orcid.org/0000-0002-5897-8605
Fatemeh Gholamali NezhadInterventional Psychiatry Program, St. Michael's Hospital, Toronto, Ontario, Canada.
Kaylyssa PhilipDepartment of Anesthesia, St. Michael's Hospital, Toronto, Ontario, Canada.ORCID https://orcid.org/0000-0002-9207-9427
Vanessa K TassoneInterventional Psychiatry Program, St. Michael's Hospital, Toronto, Ontario, Canada.ORCID https://orcid.org/0000-0002-9208-8809
Fathima AdamsahibInterventional Psychiatry Program, St. Michael's Hospital, Toronto, Ontario, Canada.
Venkat BhatInterventional Psychiatry Program, St. Michael's Hospital, Toronto, Ontario, Canada.
SMILE Study Investigators
St. Michael's Hospital · CA

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundNitrous oxide has shown potentially as an efficacious intervention for treatment-resistant depression, yet there remains insufficient evidence pertaining to repeated administration of nitrous oxide over time and active placebo-controlled studies with optimal blinding. Thus, we aim to examine the feasibility and preliminary efficacy of a six-week follow up study examining the effects of a 4 week course of weekly administered nitrous oxide as compared to the active placebo, midazolam.

methodsIn this randomized, active placebo-controlled, pilot trial, 40 participants with treatment-resistant depression will receive either inhaled nitrous oxide (1 hour at 50% concentration) plus intravenous saline (100mL) or inhaled oxygen (1 hour at 50% concentration) plus intravenous midazolam (0.02 mg/kg in 100mL, up to 2mg) once per week, for 4 consecutive weeks. Participants will be followed up for 6 weeks starting from the first treatment visit. Primary feasibility outcomes include recruitment rate, withdrawal rate, adherence, missing data, and adverse events. The primary exploratory clinical outcome is change in Montgomery-Åsberg Depression Rating Scale (MADRS) score at day 42 of the study. Other exploratory clinical outcomes include remission (defined as MADRS score <10), response (defined as ≥ 50% reduction in MADRS score), and adverse side effects. DISCUSSION: This pilot study will provide valuable information regarding the feasibility and preliminary efficacy of repeated nitrous oxide administration over time for treatment-resistant depression. If feasible, this study will inform the design of a future definitive trial of nitrous oxide as an efficacious and fast-acting treatment for treatment-resistant depression.

trial registrationClinicalTrials.gov NCT04957368. Registered on July 12, 2021.

Indexed as

DepressionNitrous OxideFollow-Up StudiesHumansMidazolamPilot ProjectsRandomized Controlled Trials as TopicTreatment OutcomeMidazolamNitrous Oxide

Identifiers

PMID38241247
PMCPMC10798444
OpenAlexW4391021908

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.