Examining the Relationship between <i>Toxoplasma gondii</i> and Seropositivity and Serointensity and Depression in Adults from the United Kingdom and the United States: A Cross-Sectional Study

• Main Authors: Shawn D. Gale, Lance D. Erickson, Bruce L. Brown, Dawson W. Hedges
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Pathogens
• Subjects: <i>Toxoplasma gondii</i>; depression; affective disorders; UK Biobank
• Online Access: https://www.mdpi.com/2076-0817/10/9/1101

Infecting approximately one-third of the world’s population, the neurotropic protozoan <i>Toxoplasma gondii</i> has been associated with cognition and several neuropsychiatric diseases including schizophrenia and bipolar disorder. Findings have been mixed, however, about the relationship between <i>Toxoplasma gondii</i> and depression, with some studies reporting positive associations and others finding no associations. To further investigate the association between <i>Toxoplasma gondii</i> and depression, we used data from the UK Biobank and the National Health and Examination Survey (NHANES). Results from adjusted multiple-regression modeling showed no significant associations between <i>Toxoplasma gondii</i> and depression in either the UK Biobank or NHANES datasets. Further, we found no significant interactions between <i>Toxoplasma gondii</i> and age, sex, educational attainment, and income in either dataset that affected the association between <i>Toxoplasma gondii</i> and depression. These results from two community-based datasets suggest that in these samples, <i>Toxoplasma gondii</i> is not associated with depression. Differences between our findings and other findings showing an association between <i>Toxoplasma gondii</i> and depression could be due to several factors including differences in socioeconomic variables, differences in <i>Toxoplasma gondii</i> strain, and use of different covariates in statistical modeling.