Does Toxoplasma gondii infection have a causal impact on human psychopathology? A Mendelian randomization analysis

Toxoplasma gondii ( T. gondii ) is a prevalent zoonotic parasite that has been implicated in influencing human psychiatric disorders and risk-taking behaviors. Using genome-wide association study (GWAS) data, we conducted two-sample Mendelian randomization (MR) analyses to investigate the potential causal relationship between T. gondii infection and the aforementioned psychiatric disorders and risk-taking behaviors. Contrary to previous epidemiological evidence, our MR analyses do not support a significant causal association between T. gondii infection and the studied psychiatric disorders or risk-taking behaviors. These findings challenge the hypothesis that chronic T. gondii influences human psychopathology and behavior.