Autoimmune-related psychosis

Autoimmune encephalitis is a neuropsychiatric disorder. While it is generally managed by neurologists, many of the presenting symptoms and most of the challenges in management are psychiatric. The description of psychiatric symptoms as part of the presenting symptoms of encephalitis dates back to the first descriptions of the disorder. The more recent discovery of autoimmune causes of encephalitis has particular relevance for psychiatry: there is significant overlap between the initial presentation of encephalitis with other core psychiatric disorders such as depression and psychosis. The particular challenge for inpatient psychiatry is to screen and detect these disorders early. The current evidence indicates that the rapid detection and delivery of immunotherapy, rather than the use of psychiatric treatments, is associated with better long-term outcomes for patients. Conversely, the risks of not detecting encephalitis are of long-term disability, or even death in a proportion of patients. This chapter describes the evolution in understanding of autoimmune encephalitis, the characteristics associated with particular antibodies, and the investigations and management of patients with autoimmune encephalitis from a psychiatric perspective.