Relationship Between Toxoplasma Gondii Infection & Mood Disorder

The Relationship Between Toxoplasma Gondii Infection and Mood Disorders in the Third National Health and Nutrition Survey

Biological Psychiatry. Available online 10 February 2012.




Toxoplasma gondii (T. gondii) is a neurotropic protozoan parasite that causes persistent infection in humans. A substantial literature suggests that schizophrenia is associated with increased seroprevalence of T. gondii, but a possible link of the parasite with mood disorders has not been as thoroughly investigated.

Methods
The association of Toxoplasma-specific immunoglobulin G results with mood disorder outcomes were examined in 7440 respondents from the third National Health and Nutrition Survey. Regression models were adjusted for numerous potential confounders, including tobacco smoking and C-reactive protein levels.

Results
- No statistically significant associations were found between T. gondii seroprevalence and a history of major depression, severe major depression, dysthymia, or dysthymia with comorbid major depression- all p values were > .05, including analysis stratified by gender.
- There was a significant relationship between T. gondii seroprevalence and bipolar disorder type I for respondents in which both manic and major depression symptoms were reported.

Conclusions
In a population-based sample, T. gondii seroprevalence is not elevated in unipolar mood disorders but is higher in a subset of respondents with a history of bipolar disorder type 1.