Schizophrenic and bipolar psychoses are chronic and disabling brain disorders that affect people of all backgrounds. It is thought that in the brain of people with schizophrenic psychosis there is a decreased amount of a receptor known as the N-acetyl methyl D-aspartate (NMDA) receptor, which normally facilitates thinking and memory. It is not known why this receptor is decreased, but a reasonable possibility is that in some people the receptor is being attacked by antibodies, produced by the body of the person with psychosis. The goal of this study is to determine whether there are increased antibodies against the NMDA receptor in cerebrospinal fluid (CSF) and serum of people with psychosis, when compared with healthy controls. Recognizing this problem is critical because when the antibodies are lowered by treatment, the NMDA receptors recover, and the psychosis would be eliminated or at least greatly improved.