Fire in the brain: How psychosis may arise when the body attacks itself

When antipsychotics are replaced with immune-suppressing drugs, patients can recover completely. But how do we identify these cases? Fire in the brain: How psychosis may arise when the body attacks itself Antibodies made by the immune system can sometimes target human brain cells, producing psychiatric symptoms.

Researchers aim to better identify such rare cases as well as fine-tune treatments. Peter Jones once treated a patient with strikingly vivid hallucinations of animals. During ward visits, the patient would stroke and interact with the critters “in as real a way as he was with me,” says Jones, an academic psychiatrist at the University of Cambridge in England.

Antipsychotic drugs did nothing to dissolve these Snow White-esque visions. But when the patient received plasma exchange –– a treatment normally reserved for a misbehaving immune system –– his hallucinations dissipated. Clearly, this was not a textbook case of schizophrenia.

Rather, the patient’s symptoms stemmed from autoimmune encephalitis, a rare form of brain inflammation that can, in some cases, cause hallucinations and other symptoms of psychosis. When these patients are treated with drugs that tamp down the immune system, the psychotic symptoms often disappear. Listening for schizophrenia: How AI could help with early diagnosis A revolutionary cancer treatment could transform autoimmune disease Autoimmune encephalitis is usually first identified through testing blood or spinal fluid for certain types of antibodies.

If patients test positive for these antibodies, it’s a sign that their immune system may be attacking the brain. Other signs can help to solidify diagnosis: bright patches of inflammation on MRI scans, quickly worsening psychotic symptoms and — importantly — clear neurological symptoms such as seizures. But Jones’ patient didn’t have those obvious neurological symptoms.

If Jones hadn’t suspected an autoimmune cause, the case likely would have been missed. Some experts suspect that the field of psychiatry is overlooking a small number of patients like this, and they are working to find more of them. They’re considering screening a broader array of psychiatric patients and seeking out new antibodies that may be involved in autoimmune encephalitis.