Detection of serum antibodies to Borna disease virus in patients with psychiatric disorders.

Borna disease virus causes a rare meningoencephalitis in horses and sheep and has been shown to produce behavioral effects in some species. The possibility that the Borna virus is associated with mental disorders in humans was evaluated by examining serum samples from 979 psychiatric patients and 200 normal volunteers for the presence of Borna virus-specific antibodies. Antibodies were detected by the indirect immunofluorescence focus assay. Antibodies to the virus were demonstrated in 16 of the patients but none of the normal volunteers. The patients with the positive serum samples were characterized by having histories of affective disorders, particularly of a cyclic nature. Further studies are needed to define the possible involvement of Borna virus in human psychiatric disturbances.