SMRI Research Update: Infectious agents may cause schizophrenia
Recent research, funded by SMRI, suggests that infectious agents may cause schizophrenia by getting in the brain several years before the person actually develops symptoms. The research is published in the January issue of the American Journal of Psychiatry and was done by David W. Niebuhr and his colleagues at the Walter Reed Army Institute of Research in Silver Spring, Md.
They examined blood samples taken from military personnel entering service and taken periodically thereafter. Among these military personnel, they identified 200 who developed schizophrenia after they entered the service and compared them with 591 matched controls. The individuals who developed schizophrenia, compared to the controls, had elevated antibodies to Toxoplasma gondii, a protozoa carried by cats, as much as three years before they initially developed symptoms of schizophrenia. This protozoa has also been linked to schizophrenia in several other studies. The Niebuhr et al. paper confirms other data suggesting that whatever causes schizophrenia probably begins several years before the disease symptoms appear.
The current publication is in the American Journal of Psychiatry, vol. 165, pages 99–106. A good review paper on Toxoplasma gondii and schizophrenia is by Torrey EF et al., in Schizophrenia Bulletin (2007), vol. 33, pages 729–736.