Anti-NMDA receptor encephalitis

Page most recently updated 7 September 2026

This page focuses on the reported psychiatric associations, which may be the initial presenting manifestation, and on other clinical features that may assist the psychiatrist or primary care physician in identifying the underlying diagnosis, considered through the lenses of the diagnostic lenses framework.

Anti-NMDA receptor encephalitis is an autoimmune encephalitis with multisystemic involvement.

It can present with psychiatric features such as acute psychosis, agitation, paranoia, hallucinations, mood symptoms, anxiety, insomnia, behavioural change, cognitive impairment, and catatonia; these may precede recognition of the underlying neurological disorder.

Other characteristic features include rapid progression of encephalopathy, seizures, dyskinesias (particularly orofacial movements), autonomic instability, altered level of consciousness, speech dysfunction, and abnormal movements.

From a multisystemic lens perspective, clinical features in other body systems include (but are not limited to):

  • Cardiovascular: autonomic instability with fluctuations in heart rate and blood pressure, which may be prominent in moderate-to-severe disease.

  • Respiratory: hypoventilation and respiratory failure may occur in severe cases, often related to central autonomic dysfunction, reduced consciousness, or prolonged illness.

  • Gastrointestinal: gastrointestinal dysmotility, reduced oral intake, and feeding difficulties may occur, particularly in severe or prolonged illness.

  • Endocrine: association with ovarian teratoma (particularly in young women), which may serve as an immune trigger.

Early diagnosis is important to reduce delays in immunotherapy and tumour detection (when applicable), decrease the risk of serious acute and chronic complications, inform tailored treatment choices, and improve neurologic recovery, prognosis, and quality of life.

Selected references and further reading — Multisystemic lens

Cardinal RN, Bullmore ET. The diagnosis of psychosis. Cambridge: Cambridge University Press; 2011.

Sachdev PS, Keshavan MS, editors. Secondary schizophrenia. Cambridge: Cambridge University Press; 2010.

Levenson JL, editor. The American Psychiatric Association Publishing textbook of psychosomatic medicine and consultation-liaison psychiatry. 3rd ed. Washington (DC): American Psychiatric Association Publishing; 2019.

Stern TA, Beach SR, Smith FA, Freudenreich O, Vranceau AM, Fava M, editors. Massachusetts General Hospital handbook of general hospital psychiatry. 8th ed. Philadelphia: Elsevier; 2025.

Arciniegas DB, Yudofsky SC, Hales RE, editors. The American Psychiatric Association Publishing textbook of neuropsychiatry and clinical neurosciences. 6th ed. Washington (DC): American Psychiatric Association Publishing; 2018.

Agrawal N, Faruqui R, Bodani M, editors. Oxford textbook of neuropsychiatry. Oxford: Oxford University Press; 2020.

Boland R, Verduin M, editors. Kaplan and Sadock's comprehensive textbook of psychiatry. 11th ed. Philadelphia: Wolters Kluwer; 2024.

Loscalzo J, Fauci AS, Kasper DL, Hauser SL, Longo DL, Jameson JL, editors. Harrison's principles of internal medicine. 22nd ed. New York: McGraw Hill; 2025.