"Latent" infection with Toxoplasma gondii: association with trait aggression and impulsivity in healthy adults

J Psychiatr Res. 2015 Jan;60:87-94. doi: 10.1016/j.jpsychires.2014.09.019. Epub 2014 Sep 28.

Abstract

Background: Latent chronic infection with Toxoplasma gondii (T. gondii), a common neurotropic pathogen, has been previously linked with suicidal self-directed violence (SSDV). We sought to determine if latent infection with T. gondii is associated with trait aggression and impulsivity, intermediate phenotypes for suicidal behavior, in psychiatrically healthy adults.

Methods: Traits of aggression and impulsivity were analyzed in relationship to IgG antibody seropositivity for T. gondii and two other latent neurotropic infections, herpes simplex virus 1 (HSV1) and cytomegalovirus (CMV). One thousand community-residing adults residing in the Munich metropolitan area with no Axis I or II conditions by SCID for DSM-IV (510 men, 490 women, mean age 53.6 ± 15.8, range 20-74). Plasma samples were tested for IgG antibodies to T. gondii, HSV-1 and CMV by ELISA. Self-reported ratings of trait aggression scores (Questionnaire for Measuring Factors of Aggression [FAF]) and trait impulsivity (Sensation-Seeking Scale-V [SSS-V]) were analyzed using linear multivariate methods.

Results: T. gondii IgG seropositivity was significantly associated with higher trait reactive aggression scores among women (p < .01), but not among men. T. gondii-positivity was also associated with higher impulsive sensation-seeking (SSS-V Disinhibition) among younger men (p < .01) aged 20-59 years old (median age = 60). All associations with HSV-1 and CMV were not significant.

Conclusions: Aggression and impulsivity, personality traits considered as endophenotypes for SSDV, are associated with latent T. gondii infection in a gender and age-specific manner, and could be further investigated as prognostic and treatment targets in T. gondii-positive individuals at risk for SSDV.

Keywords: Aggression; Impulsivity; Personality; Toxoplasma gondii.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aggression / psychology*
  • Female
  • Humans
  • Immunoglobulin G / blood*
  • Impulsive Behavior*
  • Male
  • Middle Aged
  • Personality
  • Personality Assessment
  • Risk Factors
  • Suicidal Ideation
  • Toxoplasma / immunology*
  • Toxoplasmosis / immunology
  • Toxoplasmosis / psychology*
  • Violence
  • Young Adult

Substances

  • Immunoglobulin G