To the Editor.—
In the February 1985 Archives, Roos et al1 attempted to refute the viral hypothesis of schizophrenia with results from a cerebrospinal fluid immunoglobulin study that failed to show elevations in immunoglobulin titers in schizophrenic and depressed patients compared with controls. In chronic persistent viral infections of the central nervous system (CNS), however, total immunoglobulin concentrations may not be elevated, but may be normal or even decreased.2,3 Partial immunodeficiency may actually precede the infection, causing increased susceptibility to some viruses. What is more pertinent to the viral hypothesis is the increased titers of antibodies specific to certain viruses, such as has been reported with herpes class viruses in schizophrenia.4,5 The lack of oligoclonal banding in the study by Roos et al1 is the most notable finding they have reported that refutes the role of a viral infection in this disorder, since this would