Can a Virus Cause Schizophrenia?

The purpose ofthis book isto provide acritical appraisal oftheconcept thatschizophreniacan becaused by viralinfections. The ability of viruses to cause psychiatric symptoms is not in question - the mental depression following a bout with mononucleosis or hallucinations associated with herpesencephalitisarewell-described examples. However,aviraloriginfor chronic disorders such as autism, schizophrenia, and bipolar disorder, is another matter. The claim of an infectious etiology for these disorders has beenmetinthemainstream scientific community byavagueskepticism that occasionally erupts into stringent criticism. Too often, however, the viral hypotheses of these disorders is simply disregarded; marginalized with the hopethat itwillgoaway sothatthe "serious" researchaimed atuncovering therealcauseoftheseillnesses willnotloseitsfocus.This beingsaid,much of the criticism is valid, and as a researcher with formal training in both neuroscience and viral immunology, I view the proposed viral etiology of thesedisorderswithaskepticaleye. Nevertheless, one cannot ignore the growing number of well-performed studies pointing to the role of viral infections as important antecedents of schizophreniaand other disorders inthe schizophreniaspectrum. Inthe last 30 years there have been hundreds of articles in peer-reviewed journals presenting evidenceorpositingtheoriestosuggestthatatleastsomecasesof schizophrenia have a viral origin. Moreover, many schizophrenia experts have been calling for the recognition that schizophrenia isa heterogeneous group of disorders that may have different causes. This idea of disease heterogeneity is reaching a crescendo, and there is undoubtedly a place for viruses among alternative etiologies; but we have to look. The intellectual climate tolooknowisbetterthanitwas20yearsago,inpartbecause inthe last 2 decades a number of chronic diseases of unknown etiology (e.g. gastric ulcers, Kaposi's sarcoma, hepatocellular carcinoma) have been