Does Borna Disease Virus Cause Neuropsychiatric Disorders?



K. Bechter, S.

Herzog, R. Schò

ttler. Dept. Psychiatry II University of Ulm,


Borna diseases (BD) with

it’s typical clinical course in horses and sheep is

restricted to Germany, Switzerland and Austria. However,

antibodies against Borna disease virus (BDV) can be detected

worldwide. A role of BDV in psychiatric disorders, especially

depression has been suggested (since 1985). Recently, there are

controversies about the meaning and validity of studies showing

BDV-RNA in PBMC’s of 50% of depressed patients and in the

brains of patients with various psychiatric disorders.

We have continuously performed

seroepidemiologic studies in psychiatric, neurologic and surgical

patients (n15.000) over 13 years, and have controlled

the sensitivity and specificity of serological methods by studies

of horses with natural BD (>100): Comparing the results from

serological investigations of sera and CSFs with the post

mortem diagnosis taken out with different methods (histology,

immunohistology, virus isolation, western blot), we found high

specificity and sensitivity of our serological methods (Herzog et

al, 1994).

In our human studies, we found an

increased BDV seroprevalence in psychiatric patients and a

slightly increased BDV seroprevalence in neurological patients.

An analysis of age-related dynamics of BDV seroprevalence in the

populations investigated showed that the increase of BDV

seroprevalence was due nearly exclusively from an increase in

young psychiatric patients (17 – 30 years), ages when

psychiatric disorders frequently begin. In MRI investigations we

found more frequently slight brain atrophy in BDV seropositive

patients. Most important, in about 25% of acutely diseased

BDV-seropositive psychiatric patients suffering from

schizophrenic or affective psychoses, we found pathologic

increases of BDV-specific IgG in the cerebrospinal fluids (CSF),

indicating an active although slight BDV encephalitis underlying

the respective psychosis. In one such case we recently introduced

cerebrospinal fluid filtration (CSFF) in psychiatric therapy; the

patient improved significantly, explained by removing toxic

factors during CSFF from the CSF, which were similar to that fund

earlier in neurological patients with CNS inflammatory diseases,

e.g. Guillain-Barré syndrome (GBS). CSFF had a lasting positive

effect in the schizophrenic patient similar to experiences with

CSFF in GBS. Therefore CSFF may have impact for more curative

treatments in psychiatry.