[Anti-N-methyl-D-aspartate receptor encephalitis, an essential differential diagnosis in psychiatry: a case report.].

Anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDAR encephalitis) is a rare and recently discovered disease. Affected patients are initially often referred to psychiatric departments due to prominent neuropsychiatric symptoms.We present the course of the illness of an 18-year-old female patient, who was primarily and for the first time admitted to the 1. Psychiatric Department of the Otto Wagner Hospital Vienna due to a psychotic disorder. With fluctuating clinical course, further diagnostics were performed and the patient was diagnosed with anti-NMDAR encephalitis.Anti-NMDAR encephalitis should especially be considered in young women, who suffer from a first-onset psychotic disorder in combination with neurological and vegetative symptoms.If suspected lumbar puncture is indicated. An interdisciplinary approach is indispensable for this disease and can be a challenge for psychiatrists in charge.Psychiatrists should consider encephalitis, autoimmune encephalitis in particular, as differential diagnosis in clinical practice and get more familiar with these complex conditions.