Borna disease virus infection and affective disorders in man.

Borna Disease virus (BDV) can persistently infect the central nervous system of a broad spectrum of animal species. The clinical course varies from slight behavioral disturbances to a fatal neurological syndrome. In-vivo diagnosis is based on the strong humoral immune response to BDV antigens. Since also human infections could be confirmed by specific antibodies and increased seroprevalence was found in patients with chronic neurologic or immunologic disorders, the contribution of BDV or a BDV-like human variant to syndromes with yet unknown etiology became of great interest. We presented the first data of a current follow-up study on 70 psychiatric patients who were tested three times each after hospitalization. In contrast to previously found low prevalence of antibody carriers by screening (2-4%), we now found 20% positives by follow-up testing. Furthermore, of the randomly selected patients with different psychiatric diagnosis, the highest proportion of antibody carriers was detected among patients with major depression (more than 30%), compared to only 8% among patients with dysthymia (neurotic depression). This led us to hypothesize that Bornavirus infection might contribute somehow to the syndrome of major depressive illness by altering neuronal cells in the limbic system.