Nitrous Oxide and EMOtional Cognition
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Entonox, Medical Air.
- Who it may be relevant to
- Registry conditions: Depression. Basic parameters: 18 years — 40 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United Kingdom
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Investigating the Neuropsychological Effects of Nitrous Oxide
Overview
The goal of this study is to uncover the underlying neuropsychological mechanisms of nitrous oxide, which may be relevant to its reported antidepressant effects. In particular, the study is designed to determine whether nitrous oxide changes the way in which healthy volunteers aged 18-40 years remember negative autobiographical memories. The main question the study aims to answer is: • Does nitrous oxide interfere with the emotional aspects of negative autobiographical memories? Other neuropsychological effects will also be assessed (e.g., emotional processing, emotional memory, response inhibition, and cognitive flexibility). Researchers will compare ENTONOX (50% nitrous oxide: 50% oxygen) with medical air. Participants will: * Attend three research visits (screening, inhalation, follow-up) * Take part in a 30 minute inhalation session of ENTONOX or medical air * Complete a series of cognitive tasks * Finish a series of self-report questionnaires
Detailed description
Questions regarding the mechanisms of nitrous oxide and its effects on the brain and behaviour in the context of its reported antidepressant effects remain largely unanswered. Thus, in the present study, the investigators aim to elucidate the more general effects that nitrous oxide might have on a series of neurocognitive processes which may be relevant to the treatment of depression. Namely, the study will investigate: 1) reconsolidation of autobiographical memories, 2) measures of emotional processing and emotional memory, 3) response inhibition, 4) cognitive flexibility and 5) sleep stages.
Interventions
- Drug Entonox
30 minute inhalation using demand valve and mouthpiece - Drug Medical Air
30 minute inhalation using demand valve and mouthpiece
Primary outcome measures
- Changes in Emotional Ratings of Personal Memories (Memory Reconsolidation) [Time frame: 2 days before and 1 day after treatment]
Secondary outcome measures (3)
- Performance on Emotional Processing Tasks [Time frame: Immediately before and after treatment and 1 day after treatment]
- Performance on Cognitive Flexibility Task [Time frame: 1 day after treatment]
- Performance on Response Inhibition Task [Time frame: 1 day after treatment]
Eligibility criteria
Inclusion criteria
- Aged 18-40 years
- Good vision and hearing
- Willing and able to give informed consent
- Body mass index (BMI) within the range of 18-35kg/m2 (This is to ensure we exclude underweight individuals who might have more substantial reactions to the nitrous oxide).
- Sufficiently fluent in English to understand tasks
- Willing to avoid drinking any alcohol from 3 days prior to Visit One until the end of Visit Three
- Willing to avoid using recreational drugs for 3 months prior to Visit One and throughout the duration of the study
Exclusion criteria
- Receiving or seeking treatment for any mental health condition (covered in Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders-5 (SCID) assessment in screening procedures)
- History of any mental health condition (covered in SCID assessment in screening procedures)
- Attention deficit hyperactivity disorder (ADHD) requiring treatment with stimulant or other centrally-acting drugs
- A positive drug test for any of the following: amphetamine, barbiturates, benzodiazepines, buprenorphine, cocaine, marijuana, methadone, methamphetamine, methylenedioxymethamphetamine (MDMA), morphine, methaqualone, opiates, phencyclidine, propoxyphene, tricyclic antidepressants, tramadol, ketamine, oxycodone, cotinine, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), fentanyl, synthetic marijuana, 6-mono-acetyl-morphine (6-MAM).
- Regularly drink 14 or more units of alcohol a week
- Any eye, throat or ear surgery or a medical procedure requiring intravenous injection or line into a vein in the last 6 months
- A head injury causing concussion or unconsciousness in the past 6 months
- A collapsed lung or lung surgery (e.g., pneumothorax)
- A history of cardiac arrhythmias
- Current injuries of the face or mouth (including ulcers or dental problems)
- Dental surgery in the past month
- Deep diving or scuba diving (which has a risk of decompression sickness) in past month
- Pregnancy / intention to become pregnant during the study
- Breastfeeding during the study
- Asthma, emphysema or any medical condition that affects the lungs or breathing
- Diagnosed vitamin B12 deficiency
- Any use of recreational drugs in the last three months
- Participation in any other drug study in the last three months
- Participation in any other study with the same tasks in the last year
OPTIONAL SLEEP STUDY ADD-ON Exclusion Criteria:
- Unable to undergo cardiac monitoring
- Unable to wear the sleep patch device for full monitoring period
- Implanted neurostimulator
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Triple blind
- Primary purpose
- Treatment
Study locations
United Kingdom · 1 center
- Psychiatry Department — Oxford
Identifiers
NCT: NCT06557642 · NEMO_Study