Special Issue: Toxoplasma gondii and suicidal behaviour: discovery, cross-diagnostic confirmation and pathway exploration
Abstract
Our team's discovery of the link between chronic "latent" infection with Toxoplasma gondii (Nicolle et Manceaux, 1908) and suicidal behaviour, and our subsequent cross-diagnostic confirmatory work and mechanistic extensions, evolved from our neuroimmunology studies on affective and behavioural dysregulation exacerbated by allergic sensitisation and allergen exposure. Another root was studying behavioural changes and cytokine gene expression in the brain of rodents sensitised and exposed to aeroallergens. We "piggy-backed" our project funded to study coupling between aeroallergen sensitisation and exposure in patients with recurrent mood disorders, by measuring Toxoplasma gondii (T. gondii) antibodies in existing samples, and found associations between IgG serointensity and past suicide attempts. Successively, we then reported significant associations between T. gondii seropositivity and/or serointensity and suicidal behaviour in patients with schizophrenia in Germany, recent attempters in Sweden, and longitudinally in a cohort of Danish mothers. In the Danish mothers the exposure to T. gondii preceded self-directed harm and violent suicide attempts; the association was stronger with higher serointensity strata demonstrating a dose-effect. Furthermore, we identified links between T. gondii IgG and suicide endophenotypes of aggression and impulsivity in both individuals with no history of mental illness, and in patients with Intermittent Explosive Disorder (IED). We also found…
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Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design.
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