The first thing that people think of when they see a young, handsome woman with sudden psychosis, personality change, or babbling is that she is in a psychiatric hospital, but this may delay the best treatment and cause serious neurological damage. So who is the “real killer”? Let’s take a look at a specific type of encephalitis – autoimmune encephalitis. World Encephalitis Day is celebrated every year on February 22. When it comes to encephalitis, people subconsciously think that it is caused by an infection, but many clinical encephalitis are not necessarily related to infection, and some develop suddenly after exertion. What kind of encephalitis is it? Autoimmune encephalitis was first reported by researchers at the University of Pennsylvania in 2005. Autoimmune encephalitis refers to a large group of diseases caused by antibodies in the immune system that react against antigens in the central nervous system. Antibodies are the body’s warriors that defend itself against foreign enemies such as bacteria, fungi and viruses. However, sometimes the antibodies, the warriors, can be indiscriminate and attack the body’s own tissues as enemies, resulting in the destruction of its own normal tissues, which is called autoimmune disease. When autoimmune disease attacks its own brain tissue, resulting in inflammation and damage to the brain, it can produce psychiatric and neurological symptoms, and often psychiatric symptoms are the first symptoms, and neurological signs and symptoms appear later when the disease is severe, which is autoimmune encephalopathy. The disease may recur, leading some patients to exhibit psychiatric symptoms for a long time, while neurological signs and symptoms are not obvious instead, and it is then easily misdiagnosed as various types of psychiatric disorders. Autoimmune encephalitis most often occurs in young women, with clinical prodromal symptoms including flu-like symptoms (fever, headache, fatigue), accompanied by severe psychiatric abnormalities such as delusions, confusion and hallucinations, etc. Some patients are treated as “primary psychiatric illnesses”, but the best time to treat them is often missed due to misdiagnosis. As time passes, patients develop confusion, seizures, and movement disorders, and in severe cases, coma, epilepsy, and even death. According to previous studies, most female patients with NMDAR-resistant encephalitis are often accompanied by ovarian teratomas, and removal of ovarian teratomas during treatment would greatly increase the prognosis. Treatment of autoimmune encephalitis includes immunotherapy, symptomatic treatment of seizures and psychiatric symptoms, supportive treatment, and rehabilitation. Anti-tumor therapy, such as tumor removal, is performed in cases of combined tumors (e.g., patients with anti-NMDAR encephalitis should have ovarian teratomas removed as soon as they are detected). Among them, immunotherapy is divided into first-line immunotherapy, second-line immunotherapy and long-course immunotherapy. First-line immunotherapy includes glucocorticoids, intravenous immunoglobulin (IVIg) and plasma exchange. Second-line immunotherapy drugs include rituximab and intravenous cyclophosphamide, which are mainly used for patients who have poor results with first-line immunotherapy. Long-course immunotherapeutic agents include morte-macrolimus and azathioprine, mainly in relapsed cases, but also in patients with poor first-line immunotherapy and in patients with tumor-negative anti-NMDAR encephalitis. Autoimmune encephalitis is a complex disease that often requires collaboration between multiple disciplines for effective diagnosis and treatment. 80% of anti-NMDA receptor encephalitis eventually result in partial or complete recovery, while some patients require up to 18 months of treatment to recover. In conclusion, no matter what kind of difficult disease, we would like to remind everyone that once a disease with similar symptoms is detected, it is important to seek early medical attention, diagnosis and treatment in order to obtain the best treatment time window and thus a good prognosis. In addition, young women should also pay attention to regular screening for ovarian teratoma for prevention. As a psychosomatic disease, it is important for patients to make positive self-adjustment. They need to have a regular life, ensure sufficient sleep and not stay up late; eat scientifically, drink less coffee and no alcohol; avoid strain and combine work and rest.