against Toxoplasma gondii seen among non-schizophrenics. That is not proof of
a causal relationship—or a strong enough association to explain most cases of
schizophrenia even if Toxoplasma infections are one cause of the disease. But it
is a stronger connection than has been identified for any other risk factor, note
the authors, including genetics and a family history of the disease.
The authors are cautious in their interpretation of the findings, however. "The
results suggest that individuals with schizophrenia have an increased prevalence
of antibodies to T. gondii. The association is consistent with other epidemiological
studies as well as animal studies," notes lead author Fuller Torrey. "If an
etiological association can be proven, it would have implications for...prevention
and treatment of this disease."
a causal relationship—or a strong enough association to explain most cases of
schizophrenia even if Toxoplasma infections are one cause of the disease. But it
is a stronger connection than has been identified for any other risk factor, note
the authors, including genetics and a family history of the disease.
The authors are cautious in their interpretation of the findings, however. "The
results suggest that individuals with schizophrenia have an increased prevalence
of antibodies to T. gondii. The association is consistent with other epidemiological
studies as well as animal studies," notes lead author Fuller Torrey. "If an
etiological association can be proven, it would have implications for...prevention
and treatment of this disease."
by Bryant Furlow
epiNewswire
August 26, 2007—Researchers have
long suspected that the schizophrenic's
descent into psychosis during late
adolescence and early adulthood has
its roots in the womb. An excess of
spring birthdays among schizophrenics
points to prenatal infections during the
winter respiratory-infection season,
some have argued, and scattered
reports over the years have noted
that schizophrenics often have higher
circulating levels of antibodies against
Toxoplasma gondii, implicating past
infections by protozoan parasites.
Now, a team from the Stanley Brain
Research Lab in Bethesda, MD and
Johns Hopkins University's Stanley
Laboratory of Developmental
Neurovirology in Baltimore report a
meta-analysis of numerous published
and unpublished Toxoplasma antibody
studies, confirming an overall
association between schizophrenia and
past infections. The team pooled data
from 23 studies and found that overall,
schizophrenics exhibit nearly three
times the prevalence of antibodies
epiNewswire
August 26, 2007—Researchers have
long suspected that the schizophrenic's
descent into psychosis during late
adolescence and early adulthood has
its roots in the womb. An excess of
spring birthdays among schizophrenics
points to prenatal infections during the
winter respiratory-infection season,
some have argued, and scattered
reports over the years have noted
that schizophrenics often have higher
circulating levels of antibodies against
Toxoplasma gondii, implicating past
infections by protozoan parasites.
Now, a team from the Stanley Brain
Research Lab in Bethesda, MD and
Johns Hopkins University's Stanley
Laboratory of Developmental
Neurovirology in Baltimore report a
meta-analysis of numerous published
and unpublished Toxoplasma antibody
studies, confirming an overall
association between schizophrenia and
past infections. The team pooled data
from 23 studies and found that overall,
schizophrenics exhibit nearly three
times the prevalence of antibodies
| Statistical details Data sources for the meta-analysis: 23 studies (6 unpublished) from 17 countries. Combined odds ratio (OR) for Toxoplasma antibody prevalence in schizophrenics vs. nonschizophrenics = 2.73 (95% confidence intervals: 2.10, 3.60) (Chi-square p < 0.000001) First-psychotic-episode patients only (7 studies): OR = 2.54 Patients from all clinical phases (16 studies): OR = 2.79 (p > 0.05; results not significantly different for the two clinical populations) |
Meta-analysis suggests Toxoplasma infection is a stronger risk factor than genetics
Mental Illness
Antibodies point to infection as a possible root of schizophrenia
| Further reading Torrey, EF, et al. 2007. Antibodies to Toxoplasma gondii in patients with schizophrenia: a meta-analysis. Schizophrenia Bulletin, 33(3):729-736. (Visit the online discussion group regarding this paper.) Furlow, B. 2000. Before madness: schizophrenia as a tragedy in three acts. Emory, 76(1). Furlow, B. 2001. The making of a mind: birth season and schizophrenia. New Scientist, 2300. |