Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is a form of encephalitis occurring primarily in women and associated with antibodies against NR1 or NR2 subunits of the NMDA receptor. As a potentially treatable differential for symptoms and signs seen in neurology and psychiatric clinics, clinicians practising across the lifespan should be aware of this form of encephalitis. Common clinical features include auditory and visual hallucinations, delusions, behavioural change (frequently with agitation), impaired consciousness, motor disturbance (ranging from dyskinesia to catatonia), seizures, and autonomic dysfunction. We present a review of the literature on the disorder, including its clinical presentation, differential diagnosis, epidemiology, treatment and prognosis.

We present four cases of confirmed anti-NMDA receptor encephalitis; three presented initially with serious psychiatric symptoms and the other developed significant psychiatric symptoms during the initial phase of illness. Brain biopsy findings of one patient are also described. Psychiatrists should consider anti-NMDA receptor encephalitis in patients presenting with psychosis and additional features of dyskinesias, seizures and catatonia, particularly where there is no previous history of psychiatric disorder.

Objectives To determine if the initial COVID-19 societal restrictions, introduced in Ireland in March 2020, impacted on the number and nature of psychiatry presentations to the emergency department (ED) of a large academic teaching hospital. Methods We examined anonymised clinical data of psychiatry presentations to the ED during the initial 8-week period of COVID-19 restrictions. Data from corresponding 8-week periods in 2018 and 2019 were also extracted for comparison. Results Psychiatry presentations to ED reduced by 21% during the COVID-19 restrictions, from 24/week to 19/week when compared with corresponding periods in 2018/2019 (1-way 2-sample Poisson Rate Test estimate of difference -5.2/week, 95% CI 1.3-9.1, p = 0.012). Numbers attending for out of hours assessment remained unchanged (81 vs 80), but numbers seeking assessment during normal hours decreased (71 vs 114). We observed increased presentations from the <18 age group, but decreased presentations from the 18-29 age group (Pearson Chi-Square 20.363, DF = 6, p = 0.002). We recorded an increase in anxiety disorders during the initial COVID-19 restrictions (31 vs 23), and a reduction in alcohol disorders (28 vs 52). The proportion of presentations with suicidal ideation or self-harm as factors remained unchanged. Conclusions Rates of emergency presentation with mental illness reduced during the initial COVID-19 restrictions. This may represent an unmet burden of mental health need. Younger people may be experiencing greater distress and mental illness during the current crisis. More people sought help for anxiety disorders during the COVID-19 restrictions compared with corresponding data from 2018/2019.