Antibodies to Infectious Agents in Individuals at Ultra-High Risk for Psychosis
Received 12 November 2005; received in revised form 26 September 2006; accepted 29 September 2006. published online 04 January 2007.
Background
While there is evidence that some cases of schizophrenia may be associated with microbial infections, the role of microbial agents has not been investigated in people with emerging psychosis.
Methods
Participants were 105 help seeking ultra-high risk individuals. Psychiatric measures included the Brief Psychiatric Rating Scale and the Scale for the Assessment of Negative Symptoms. Serum IgG antibodies against human herpesviruses and Toxoplasma gondii were determined using immunoassay methods. Multiple linear regression with adjustment for age and sex was applied to test associations between serum antibodies and psychiatric measures.
Results
Higher levels of serum IgG antibodies against Toxoplasma gondii in Toxoplasma-positive individuals were significantly associated with more severe positive psychotic symptoms. No significant association was observed between antibody levels and psychiatric measures in individuals positive for human herpesviruses.
Conclusions
In some individuals infection with Toxoplasma gondii may be an environmental factor contributing to the manifestation of positive psychotic symptoms.
aORYGEN Research Centre (incorporating the Personal Assistance and Crises Evaluation [PACE] Clinic), Department of Psychiatry, University of Melbourne, Australia
bDepartment of Child and Adolescent Psychiatry, Medical University of Vienna, Austria
cJohn Hopkins University School of Medicine, Stanley Division of Developmental Neurovirology, Baltimore, Maryland.
Address reprint requests to Dr. G. Paul Amminger, Department of Child and Adolescent Psychiatry, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
ABSTRACT