Antibodies directed to the surface structures of nerve cells may cause autoimmune encephalitis. It may cause limbic encephalitis requiring intensive care, or symptoms are restricted to psychosis. This disease may be impossible to distinguish clinically from a functional psychotic illness. Some of the cases are paraneoplastic, i.e. associated with a diagnosed or latent malignant neoplasia, most commonly ovarian teratoma. The first line treatment for autoimmune encephalitis is an immunomodulatory combination therapy with immunoglobulin and methylprednisolone. We recommend screening of the most common NMDAR and VGKC antibodies related to autoimmune encephalitis from patients having developed a new psychosis.