We used polymerase chain reaction to search for nucleic acid sequences of several viruses in DNA and RNA extracted from brain tissues of schizophrenic and control subjects.
We extracted DNA and RNA templates from frozen brain specimens of 31 patients with schizophrenia and 23 nonschizophrenic control patients with other diseases. The extracts were subjected to polymerase chain reaction with oligonucleotide primers for 12 different viruses (cytomegalovirus, Epstein-Barr virus, herpes simplex virus type 1, human herpesvirus type 6, varicellazoster virus, measles virus, mumps virus, rubella virus, the picornavirus group, influenza A virus, human T-cell lymphotropic virus type I, and St Louis encephalitis virus), several of which have been suspected of involvement in schizophrenia. Nested primers were used to increase the sensitivity of the method.
No amplified nucleic acid sequences encoded by the selected viral genomes were detected in extracts of any brain specimens from either schizophrenic or control patients.
These data agree with previous studies that failed to find sequences of a number of viruses in the cerebrospinal fluid or selected areas of the brains of schizophrenic patients. Additional efforts should be undertaken to identify other known and unknown pathogens in schizophrenia, sampling more areas of the brain from subjects with a variety of clinical types of schizophrenia.