A viral disease long suspected of possibly causing mental illness has apparently been acquitted, as a blinded case-control study found no association between the Borna disease virus (BDV) and mental health disorders.
Prior studies have linked the virus to mental illnesses such as bipolar disorder, schizophrenia, anxiety disorder and dementia. Investigators were open-minded to the possibility as genetic fragments and antibodies to this RNA virus causes behavior disorders in a range of mammals and birds.
Moreover, although the results have been inconclusive, traces of the virus have been found to be prevalent in psychiatric patients.
But Mady Hornig, M.D., director of translational research at the Center for Infection and Immunity (CII) at Columbia University, said, “Our study provides compelling evidence that bornaviruses do not play a role in schizophrenia or mood disorders.”
Hornig and collaborators at seven other institutions in the U.S, Germany and Australia, published their findings online in the journal Molecular Psychiatry.
As part of the study, scientists evaluated 198 patients in California with schizophrenia, bipolar disorder and major depressive disorder. They then carefully matched each one of them with a healthy control of the same sex, age, region and socio-economic status, and tested blood of patients and controls for the presence of BDV genetic material and antibodies to BDV.
The investigators hypothesized that if the virus was, in fact, associated with a psychiatric disorder, genetic evidence of infection would be apparent in blood samples taken at the onset and/or at the peak of a psychiatric episode, and antibody evidence would be detectable several weeks afterward.
To test the hypothesis, blood samples were collected within six weeks of the onset of an acute mental episode or upon clinically significant worsening of symptoms. Blood samples were then taken again after six weeks to allow for changes in viral load or antibody levels.
Researchers found no evidence of active or historical infection with BDV in any of the subjects, nor did they discover a relationship between mental illness and bornavirus.
In a commentary in the same issue of the journal, Michael B.A. Oldstone, M.D., an expert in molecular virology and central nervous system infections at the Scripps Research Institute, observes that the design and experimental procedures carried out in the Hornig study provide a gold standard for investigating links between persistent viral infection and human disease.
CII director, W. Ian Lipkin, M.D., senior author of the paper, notes that “it was concern over the potential role of BDV in mental illness and the inability to identify it using classical techniques led us to develop molecular methods for pathogen discovery.
“Ultimately these new techniques enabled us to refute a role for BDV in human disease. But the fact remains that we gained strategies for the discovery of hundreds of other pathogens that have important implications for medicine, agriculture and environmental health.”
Source: Columbia University