No association between current depression and latent toxoplasmosis in adults

Abstract

Changes in behaviour and cognition have been associated with latent infection from the apicomplexan protozoan Toxoplasma gondii (Nicolle et Manceaux, 1908) in both animal and human studies. Further, neuropsychiatric disorders such as schizophrenia have also been associated with latent toxoplasmosis. Previously, we found no association between T. gondii immunoglobulin G antibody (IgG) seropositivity and depression in human adults between the ages of 20 and 39 years (n = 1 846) in a sample representative of the United States collected by the Centers for Disease Control as part of a National Health and Nutrition Examination Survey (NHANES) from three datasets collected between 1999-2004. In the present study, we used NHANES data collected between 2009 and 2012 that included subjects aged 20 to 80 years (n = 5 487) and used the Patient Health Questionnaire 9 (PHQ-9) to assess depression with the overall aim of testing the stability of the results of the prior study. In the current study, the seroprevalence of T. gondii was 13%. The percentage of subjects reporting clinical levels of depression assessed with the PHQ-9 was 8%. As before, we found no association between T. gondii IgG seroprevalence and depression (OR = 1.01, 95% CI = 0.81-1.25; p = 0.944) while controlling for sex, educational attainment, race-ethnicity, age, poverty-to-income ratio and cigarette smoking. We also found no positive associations between anti-T. gondii antibody titre and depression (OR = 1.00, 95% CI = 0.96-1.06; p = 0.868). Moreover, we found no association between T. gondii seroprevalence or antibody titre and suicidal ideation (seroprevalence: OR = 1.22, 95% CI = .85-1.75; p = 0.277, titre: OR = 1.05, 95% CI = 0.98-1.14; p = 0.177). Defining depression to also include subjects currently taking antidepressant medication even with non-elevated questionnaires did not find evidence of a positive association between latent toxoplasmosis and depression. In the present study, neither T. gondii seroprevalence nor anti-T. gondii antibody titre was positively associated with depression or suicidal ideation among subjects aged 20 to 80 years.

Positive association between Toxoplasma gondii IgG serointensity and current dysphoria/hopelessness scores in the Old Order Amish: a preliminary study

“…However, our results are inconsistent with other studies that found no associations between T. gondii infection and symptoms of depression [14, 23, 29–32, 42–46]. Many of these studies had limitations in terms of not adjusting for confounders such as occupation, heritability, living environment, cultural practices, socioeconomic status and substance use disorders.…”

“…Chronic T. gondii infection has also been associated with depression in psychiatric patients [26], women Veterans [27] and pregnant women [28]. However, several other studies found no association between T. gondii infection and depression [23,29–32]. One potential source of this discrepancy may be the heterogeneity of samples studied.…”

Evolutionary puzzle of Toxoplasma gondii with suicidal ideation and suicide attempts: An updated systematic review and meta-analysis

“…Thereafter, 9,130 records were excluded through an initial screening of the titles and/or abstracts. The remaining 85 full-text articles were assessed, out of which 27 studies were further compared against our inclusion criteria (Akgül, 2019;Alvarado-Esquivel et al, 2015;Alvarado-Esquivel et al, 2013;Ansari-Lari et al, 2017;Arling et al, 2009;Bak et al, 2018;Burgdorf et al, 2019;Coccaro et al, 2016;Coryell et al, 2016;Dickerson et al, 2018;Dickerson et al, 2017;Ene et al, 2016;Fond et al, 2015;Fond et al, 2018;Gale et al, 2016;Okusaga et al, 2011;Pedersen et al, 2012;Samojlowicz et al, 2013;Samojłowicz et al, 2017;Sapmaz et al, 2019;Sari & Kara, 2019;Sugden et al, 2016;Yagmur et al, 2010;Zhang et al, 2012). Finally, 26 data sets from the 25 records were included in this meta-analysis ( Figure 1).…”

“…Available data suggest that a positive T. gondii antibody titre is probably linked to affective and behavioural changes, as demonstrated in animal and human models (Duffy et al, 2015) (Flegr, 2007;Mann, 2003;Webster, 2001Webster, , 2007. Although some available findings demonstrated a hypothesized relationship between suicide rates and T. gondii infection (Akgül, 2019;Bak et al, 2018;Burgdorf et al, 2019;Pedersen, Mortensen, Norgaard-Pedersen, & Postolache, 2012;Samojłowicz, Borowska-Solonynko, & Kruczyk, 2017;Sapmaz, Şen, Özkan, & Kandemir, 2019;Yagmur, Yazar, Temel, & Cavusoglu, 2010), contradictory results also exist in this regard (Alvarado-Esquivel et al, 2015;Alvarado-Esquivel et al, 2013;Ansari-Lari, Farashbandi, & Mohammadi, 2017;Arling et al, 2009;Coccaro et al, 2016;Coryell et al, 2016;Fond et al, 2015;Fond et al, 2018;Gale, Berrett, Brown, Erickson, & Hedges, 2016;Samojlowicz, Borowska-Solonynko, & Golab, 2013;Sari & Kara, 2019;Sugden et al, 2016;Yolken & Torrey, 2008;Zhang et al, 2012). For SA, we updated the findings of the previous meta-analysis (Sutterland et al, 2019), apart from the inclusion of more databases and articles on SA in an attempt to improve the statistical power to assess the association between T. gondii infection and SA.…”

Fetomaternal and Pediatric Toxoplasmosis

“…In a trial using Patient Health Questionnaire Survey data collected by National Health and Nutrition Examination (2009-2012), no association was reported between Toxoplasma-seropositives (13%) and incidence of depression (8%) or suicidal thoughts in the subjects. 40…”