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Just say N2O – nitrous oxide misuse: essential information for psychiatrists

  • Rollo J. G. Sheldon (a1), Michael Reid (a2), Frederick Schon (a3) and Norman A. Poole (a4)


Nitrous oxide (N2O) misuse is widespread in the UK. Although it is well-known that it can cause devastating myeloneuropathy, psychiatric presentations are poorly described. There is little understanding of who it affects, how it presents, its mechanism of action and principles of treatment. We begin this article with a case study. We then review the literature to help psychiatrists understand this area and deal with this increasing problem, and make diagnosis and treatment recommendations. We describe a diagnostic pentad of weakness, numbness, paraesthesia, psychosis and cognitive impairment to alert clinicians to the need to urgently treat these patients. Nitrous oxide misuse is a pending neuropsychiatric emergency requiring urgent treatment with vitamin B12 to prevent potentially irreversible neurological and psychiatric symptoms.


After reading this article you will be able to:

  • understand the epidemiological and clinical features of nitrous oxide misuse
  • understand the mechanisms of action of nitrous oxide
  • describe potential treatment options in nitrous oxide misuse.




Corresponding author

Correspondence Rollo Sheldon, West Brighton Assessment and Treatment Service, Hove Polyclinic, Nevill Avenue, Hove BN3 7HY, UK. Email:


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Just say N2O – nitrous oxide misuse: essential information for psychiatrists

  • Rollo J. G. Sheldon (a1), Michael Reid (a2), Frederick Schon (a3) and Norman A. Poole (a4)
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