Research suggests that some cases of psychosis, diagnosed as schizophrenia, may actually be the result of autoimmune encephalitis. Many people with schizophrenia experience psychosis: hallucinations, delusions, paranoia, or even catatonia. However, symptoms can vary wildly among patients in their presentation and severity. For some, the disease is only a small setback in an otherwise fully functional life. Learn More About Schizophrenia » Like autism, schizophrenia is diagnosed based on symptoms alone. “Schizophrenia may represent a common clinical syndrome that most likely represents many different diseases,” explained neuroscience expert Stuart C. Sealfon M.D., Chairman of Neurology at the Icahn School of Medicine at Mount Sinai, in an interview with Healthline. The standard treatment for schizophrenia is antipsychotic drugs. These drugs can carry a range of nasty side effects, and they help some patients much more than others. Read About Different Types of Schizophrenia and How to Treat Them »

Inflammation on the Brain A researcher at the University of Oxford, Belinda Lennox, and her team may have found one of the diseases that’s currently misdiagnosed as schizophrenia: encephalitis, or inflammation of the brain. The team examined 46 patients who had experienced their first episode of psychosis. In three of the people—around six percent—they found antibodies that specifically target nerve cells. Antibodies direct the body’s immune system, telling white blood cells what to attack and what to leave alone. Normally, antibodies target viruses and bacteria, allowing the immune system to fight off infections. But in the case of autoimmune diseases, the antibodies target the body’s own cells for destruction. In this case, the antibodies were attacking a structure called the NMDA receptor, an important protein found on the surface of many nerve cells that allows them to receive signals from other nerve cells. The receptor is found throughout the brain and is involved in the formation of new memories. When the immune system attacks the NMDA receptor, it becomes inflamed, and one of the possible symptoms is psychosis. Find Out More About Encephalitis »

Clean the Blood, Protect the Brain To test this theory—and to help their patient—the team treated one man with plasmapheresis, a procedure that filters antibodies out of the blood. They also gave him prednisone, a steroid medication that suppresses the immune system. His psychotic symptoms improved without any antipsychotic drugs. “This is the first case description, to our knowledge, of a patient with NMDA [receptor] antibodies and a purely psychiatric presentation responding to immunotherapy,” Lennox wrote. Other data suggest that for this treatment to work, the psychosis has to be caught early. A larger study of people with chronic schizophrenia didn’t find the NMDA receptor antibodies, leading to two possible conclusions. Either the antibodies fade from the bloodstream over time, leaving behind the damage they’ve caused, or these patients have schizophrenia due to other causes. Since then, Lennox has been screening incoming early-psychosis patients for the anti-NMDA antibodies and treating those who test positive. “I’m cautious to claim any results because it hasn’t been done in a randomized controlled way,” she said in an interview with The Naked Scientists. “But we have treated about 20 patients now, and each patient has improved with the psychiatric symptoms so far.” Read More: What Causes Schizophrenia? »