Effects of Toxoplasma gondii infection on cognition, symptoms, and response to digital cognitive training in schizophrenia

Abstract

Studies indicate that neuroscience-informed digital cognitive training can remediate cognitive impairments in schizophrenia, but the factors contributing to these deficits and response to treatment remain unclear. Toxoplasma gondii is a neuroinvasive parasite linked to cognitive decline that also presents a higher prevalence in schizophrenia. Here, we compared the cognition and symptom severity of IgG seropositive (TOXO+; n = 25) and seronegative (TOXO−; n = 35) patients who participated in a randomized controlled trial of digital cognitive training. At baseline, TOXO+ subjects presented lower global cognition than TOXO− (F = 3.78, p = 0.05). Specifically, TOXO+ subjects showed worse verbal memory and learning (F = 4.48, p = 0.03), social cognition (F = 5.71, p = 0.02), and higher antibody concentrations were associated with increased negative (r = 0.42, p = 0.04) and total (r = 0.40, p = 0.04) schizophrenia symptoms. After training, the TOXO+ group showed higher adherence to the intervention (X2 = 9.31, p = 0.03), but there were no differences in changes in cognition and symptoms between groups. These findings highlight the association between seropositivity to T. gondii and deteriorated cognition and symptoms in schizophrenia. Further research is needed to assess the specific efficacy of digital cognitive training on this population.

Seroprevalencia de Toxoplasma gondii y su relación con trastornos mentales en adultos

“…Los individuos con esquizofrenia que se encuentran con infección por T. gondii, tienden a presentar un empeoramiento considerable, en diversas esferas cognitivas; Guimarães et al señala que los pacientes con IgG positivo para T. gondii, pueden evolucionar con deficiencias en la cognición social y aprendizaje verbal, e incluso en la memoria visual, a diferencia del aprendizaje cognitivo digital en los que desarrollaron una mejor adherencia 21 .…”

AccessSeroprevalence and the Associated Risk Factorsof Toxoplasma GondiiInfection among PregnantWomenin The Middle Belt of Ghana

“…Being positive for IgM could indicate either a new infection or a reactivated past infection (particularly in pregnant women who tested positive for both anti-T. gondii IgG and IgM), which has been reported to occur in immunocompromised individuals . Primary congenital toxoplasmosis can occur through trans-plancental parasite transmission to the fetus, with the risk of transmission rising during gestation (Munoz et al, 2011;Robert-Gangneux and Dardé, 2012;Guimarães et al, 2022). The detection of both anti-T. gondii IgM and anti-T. gondii IgG antibodies in circulation in sero-epidemiological studies for T. gondii infection is always an indication of acute infection.…”

“…Toxoplasma gondii is an obligate intracellular coccidian parasite that affects primarily members of the felid family but also most genera of warm-blooded animals, including birds and humans (Meerburg et al, 2006;Dubey and Jones, 2008;Guimarães et al, 2022). Toxoplasma gondii causes the disease toxoplasmosis and typically requires alternation of sexual and asexual reproductive stages in its life cycle (Hill et al, 2010).…”