Schizophrenia has complex and multifactorial etiologies, with family history of psychiatric disorders as one of the main contributing risk factors. However, family history is unlikely to be a sufficient cause. Recently, immunological hypotheses have become increasingly prominent (1), and both autoimmune diseases and infections have been suggested to be causally linked to schizophrenia (2–6). The immune system can produce autoantibodies that react against the body's own tissue, inducing autoimmune diseases. Some autoantibodies that can cross-react with brain tissue have been associated with psychiatric and neurological disorders (7). The brain is protected by the blood-brain barrier (8), and in order for autoimmune diseases to induce a syndrome in the CNS, an insult that compromises this barrier might be required (9). There is a range of possible insults, including stress of various types as well as infections and inflammation. Insults that increase the permeability of the blood-brain barrier may permit the influx of brain-reactive antibodies or other immune components into the brain