Population-based cohort study of Toxoplasma gondii P22 antibody positivity correlation with anxiety

J Affect Disord. 2024 May 8:359:41-48. doi: 10.1016/j.jad.2024.05.043. Online ahead of print.

Abstract

Background: Accumulating evidence suggests that latent infection with Toxoplasma gondii (T. gondii) is associated with a variety of neuropsychiatric and behavioral conditions. This research aims to explore the potential correlation between T. gondii antibody positivity and neuropsychiatric disorders through a comprehensive prospective cohort study.

Methods: The cohort study utilized the UK Biobank database to recruit 8814 individuals with no prior diagnosis of neuropsychiatric disorders. Cox proportional hazards models were employed to investigate the associations between T. gondii P22 antibody seropositivity (P22+) and the development of various types of neuropsychiatric disorders.

Results: Of the population, 14.65 % tested positive for T. gondii P22 antibody. The presence of T. gondii P22 antibody showed a slight inverse association with epilepsy (HR: 0.28; 95 % CI: 0.10-0.77), while it was positively associated with an increased risk of developing anxiety disorders (HR: 1.38; 95 % CI: 1.04-1.83).

Limitations: The study sample consisted mostly of white British individuals aged 40 to 69 years old. Although we adjusted for potential confounders, there may be other unmeasured and residual confounding factors that could have influenced our reported associations.

Conclusions: The findings suggested an increased risk of anxiety and potential evidence of epilepsy associated with T. gondii P22+. However, our analysis did not reveal an increased risk of several other neuropsychiatric conditions including Alzheimer's disease, dementia, substance abuse disorders, depression, and neurodegenerative disorders, associated with P22 antibody seropositivity.

Keywords: Anxiety; Neuropsychiatric disorders; Prospective cohort study; Toxoplasma gondii; UK Biobank.