Nitrous oxide speeds the reduction of distressing intrusive memories in an experimental model of psychological trauma

R K Das, A Tamman, V Nikolova, T P Freeman, J A Bisby, A I Lazzarino, S K Kamboj

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

BACKGROUND: Post-traumatic stress disorder (PTSD) involves maladaptive long-term memory formation which underlies involuntary intrusive thoughts about the trauma. Preventing the development of such maladaptive memory is a key aim in preventing the development of PTSD. We examined whether the N-methyl d-aspartate receptor (NMDAR) antagonist gas nitrous oxide (N2O) could reduce the frequency of intrusive memories by inhibiting NMDAR-dependent memory consolidation in a laboratory analogue of psychological trauma.

METHOD: Participants were randomized to inhale N2O (N = 25) or medical air (N = 25) after viewing a negatively valenced emotional film clip ('trauma film'). Participants subsequently completed a daily diary assessing frequency of intrusive thoughts relating to the film clip. A week later, participants completed an explicit memory recall task related to the film.

RESULTS: Post-encoding N2O sped the reduction in intrusive memory frequency, with a significant reduction by the next day in the N2O group compared to 4 days later in the air group. N2O also interacted with post-film dissociation, producing increased intrusion frequency in those who were highly dissociated at baseline. Sleep length and quality the night after viewing the film did not differ between the groups.

CONCLUSION: N2O speeds the reduction of intrusive analogue trauma memory in a time-dependent manner, consistent with sleep-dependent long-term consolidation disruption. Further research with this drug is warranted to determine its potential to inoculate against enduring effects of psychological trauma; however, caution is also urged in dissociated individuals where N2O may aggravate PTSD-like symptomatology.

LanguageEnglish
Pages1749-1759
Number of pages11
JournalPsychological Medicine
Volume46
Issue number8
Early online date4 Mar 2016
DOIs
StatusPublished - 1 Jun 2016

Fingerprint

Nitrous Oxide
Theoretical Models
Post-Traumatic Stress Disorders
Motion Pictures
Surgical Instruments
Sleep
Wounds and Injuries
Air
Dissociative Disorders
Long-Term Memory
Gases
Psychological Trauma
Research
Pharmaceutical Preparations
aspartic acid receptor

Keywords

  • Adolescent
  • Adult
  • Analgesics, Non-Narcotic/pharmacology
  • Female
  • Heart Rate
  • Humans
  • Male
  • Memory/drug effects
  • Memory Consolidation/drug effects
  • Mental Recall/drug effects
  • Models, Theoretical
  • Nitrous Oxide/pharmacology
  • Psychological Trauma/physiopathology
  • Sleep
  • Stress Disorders, Post-Traumatic/psychology
  • Young Adult

Cite this

Nitrous oxide speeds the reduction of distressing intrusive memories in an experimental model of psychological trauma. / Das, R K; Tamman, A; Nikolova, V; Freeman, T P; Bisby, J A; Lazzarino, A I; Kamboj, S K.

In: Psychological Medicine, Vol. 46, No. 8, 01.06.2016, p. 1749-1759.

Research output: Contribution to journalArticle

Das, R K ; Tamman, A ; Nikolova, V ; Freeman, T P ; Bisby, J A ; Lazzarino, A I ; Kamboj, S K. / Nitrous oxide speeds the reduction of distressing intrusive memories in an experimental model of psychological trauma. In: Psychological Medicine. 2016 ; Vol. 46, No. 8. pp. 1749-1759.
@article{1c42fa90e57d45d5b9209d40a7b02af7,
title = "Nitrous oxide speeds the reduction of distressing intrusive memories in an experimental model of psychological trauma",
abstract = "BACKGROUND: Post-traumatic stress disorder (PTSD) involves maladaptive long-term memory formation which underlies involuntary intrusive thoughts about the trauma. Preventing the development of such maladaptive memory is a key aim in preventing the development of PTSD. We examined whether the N-methyl d-aspartate receptor (NMDAR) antagonist gas nitrous oxide (N2O) could reduce the frequency of intrusive memories by inhibiting NMDAR-dependent memory consolidation in a laboratory analogue of psychological trauma.METHOD: Participants were randomized to inhale N2O (N = 25) or medical air (N = 25) after viewing a negatively valenced emotional film clip ('trauma film'). Participants subsequently completed a daily diary assessing frequency of intrusive thoughts relating to the film clip. A week later, participants completed an explicit memory recall task related to the film.RESULTS: Post-encoding N2O sped the reduction in intrusive memory frequency, with a significant reduction by the next day in the N2O group compared to 4 days later in the air group. N2O also interacted with post-film dissociation, producing increased intrusion frequency in those who were highly dissociated at baseline. Sleep length and quality the night after viewing the film did not differ between the groups.CONCLUSION: N2O speeds the reduction of intrusive analogue trauma memory in a time-dependent manner, consistent with sleep-dependent long-term consolidation disruption. Further research with this drug is warranted to determine its potential to inoculate against enduring effects of psychological trauma; however, caution is also urged in dissociated individuals where N2O may aggravate PTSD-like symptomatology.",
keywords = "Adolescent, Adult, Analgesics, Non-Narcotic/pharmacology, Female, Heart Rate, Humans, Male, Memory/drug effects, Memory Consolidation/drug effects, Mental Recall/drug effects, Models, Theoretical, Nitrous Oxide/pharmacology, Psychological Trauma/physiopathology, Sleep, Stress Disorders, Post-Traumatic/psychology, Young Adult",
author = "Das, {R K} and A Tamman and V Nikolova and Freeman, {T P} and Bisby, {J A} and Lazzarino, {A I} and Kamboj, {S K}",
year = "2016",
month = "6",
day = "1",
doi = "10.1017/S003329171600026X",
language = "English",
volume = "46",
pages = "1749--1759",
journal = "Psychological Medicine",
issn = "1469-8978",
publisher = "Cambridge University Press",
number = "8",

}

TY - JOUR

T1 - Nitrous oxide speeds the reduction of distressing intrusive memories in an experimental model of psychological trauma

AU - Das, R K

AU - Tamman, A

AU - Nikolova, V

AU - Freeman, T P

AU - Bisby, J A

AU - Lazzarino, A I

AU - Kamboj, S K

PY - 2016/6/1

Y1 - 2016/6/1

N2 - BACKGROUND: Post-traumatic stress disorder (PTSD) involves maladaptive long-term memory formation which underlies involuntary intrusive thoughts about the trauma. Preventing the development of such maladaptive memory is a key aim in preventing the development of PTSD. We examined whether the N-methyl d-aspartate receptor (NMDAR) antagonist gas nitrous oxide (N2O) could reduce the frequency of intrusive memories by inhibiting NMDAR-dependent memory consolidation in a laboratory analogue of psychological trauma.METHOD: Participants were randomized to inhale N2O (N = 25) or medical air (N = 25) after viewing a negatively valenced emotional film clip ('trauma film'). Participants subsequently completed a daily diary assessing frequency of intrusive thoughts relating to the film clip. A week later, participants completed an explicit memory recall task related to the film.RESULTS: Post-encoding N2O sped the reduction in intrusive memory frequency, with a significant reduction by the next day in the N2O group compared to 4 days later in the air group. N2O also interacted with post-film dissociation, producing increased intrusion frequency in those who were highly dissociated at baseline. Sleep length and quality the night after viewing the film did not differ between the groups.CONCLUSION: N2O speeds the reduction of intrusive analogue trauma memory in a time-dependent manner, consistent with sleep-dependent long-term consolidation disruption. Further research with this drug is warranted to determine its potential to inoculate against enduring effects of psychological trauma; however, caution is also urged in dissociated individuals where N2O may aggravate PTSD-like symptomatology.

AB - BACKGROUND: Post-traumatic stress disorder (PTSD) involves maladaptive long-term memory formation which underlies involuntary intrusive thoughts about the trauma. Preventing the development of such maladaptive memory is a key aim in preventing the development of PTSD. We examined whether the N-methyl d-aspartate receptor (NMDAR) antagonist gas nitrous oxide (N2O) could reduce the frequency of intrusive memories by inhibiting NMDAR-dependent memory consolidation in a laboratory analogue of psychological trauma.METHOD: Participants were randomized to inhale N2O (N = 25) or medical air (N = 25) after viewing a negatively valenced emotional film clip ('trauma film'). Participants subsequently completed a daily diary assessing frequency of intrusive thoughts relating to the film clip. A week later, participants completed an explicit memory recall task related to the film.RESULTS: Post-encoding N2O sped the reduction in intrusive memory frequency, with a significant reduction by the next day in the N2O group compared to 4 days later in the air group. N2O also interacted with post-film dissociation, producing increased intrusion frequency in those who were highly dissociated at baseline. Sleep length and quality the night after viewing the film did not differ between the groups.CONCLUSION: N2O speeds the reduction of intrusive analogue trauma memory in a time-dependent manner, consistent with sleep-dependent long-term consolidation disruption. Further research with this drug is warranted to determine its potential to inoculate against enduring effects of psychological trauma; however, caution is also urged in dissociated individuals where N2O may aggravate PTSD-like symptomatology.

KW - Adolescent

KW - Adult

KW - Analgesics, Non-Narcotic/pharmacology

KW - Female

KW - Heart Rate

KW - Humans

KW - Male

KW - Memory/drug effects

KW - Memory Consolidation/drug effects

KW - Mental Recall/drug effects

KW - Models, Theoretical

KW - Nitrous Oxide/pharmacology

KW - Psychological Trauma/physiopathology

KW - Sleep

KW - Stress Disorders, Post-Traumatic/psychology

KW - Young Adult

U2 - 10.1017/S003329171600026X

DO - 10.1017/S003329171600026X

M3 - Article

VL - 46

SP - 1749

EP - 1759

JO - Psychological Medicine

T2 - Psychological Medicine

JF - Psychological Medicine

SN - 1469-8978

IS - 8

ER -