anxiety

Latent toxoplasmosis and psychiatric symptoms – A role of tryptophan metabolism?

January 31, 2020
Latent toxoplasmosis and psychiatric symptoms - A role of tryptophan metabolism?
Journal of Psychiatric Research 2019, 110: 45 - 50

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Toxoplasma gondii (TOX) is a common parasite which infects approximately one third of the human population. In recent years, it has been suggested that latent toxoplasmosis may be a risk factor for the development of mental disorders, particularly schizophrenia and anxiety. With regards to depression the results have been varied. The main objective of this study was to examine subpopulations from the Danish PRISME and GENDEP populations for TOX IgG antibodies. These consisted of: a group with symptoms of anxiety, a group suffering from burnout syndrome, as well as two different subpopulations with depression of differing severity. The secondary objective of this study was to examine whether tryptophan metabolism was altered in TOX-positive subjects within each subpopulation. Our results show that the anxiety and burnout populations were more likely to be TOX IgG seropositive. Furthermore, we find that the moderate-severe but not mild-moderate depressive subpopulation were associated with TOX seropositivety, suggesting a possible role of symptom severity. Additionally, we found that TOX positive subjects in the anxiety and burnout subpopulations had altered tryptophan metabolism. This relationship did not exist in the mild-moderate depressive subpopulation. These results suggest that TOX seropositivity may be related to anxiety, burnout and potentially to severity of depression. We furthermore show that the psychiatric symptoms could be associated with an altered tryptophan metabolism.

Tagged: 3 ioxygenasepattern, antidepressant, anxiety, burnoutdepression, common mental- disorders, depression reistant, gondii infection, indoleamine 2, kynurenine, pathway, Toxoplsma gondii, tryptophan

Mental health

The association between suicide attempts and Toxoplasma gondii infection

May 3, 2018
Bak, J. Shim, S.H., Kwon, Y.J., Lee, H.Y., Kim, J.S., Yoon, H., Lee, Y.J.
Clinical Psychopharmacology Neuroscience 2018; 16: 95-102

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Objective: Chronic 'latent' infection by Toxoplasma gondii is common and most of the hosts have minimal symptoms or they are even asymptomatic. However, there are possible mechanisms by which T. gondii may affect human behavior and it may also cause humans to attempt suicide. This article aimed to investigate the potential pathophysiological relationship between suicide attempts and T. gondii infection in Korea. Methods: One hundred fifty-five psychiatric patients with a history of suicide attempt and 135 healthy control individuals were examined with enzyme-linked immunoassays and fluorescent antibody technique for T. gondii seropositivity and antibody titers. The group of suicide attempters was interviewed regarding the history of suicide attempt during lifetime and evaluated using 17-item Korean version of Hamilton Depression Scale (HAMD), Columbia Suicide Severity Rating Scale (C-SSRS), State-Trait Anxiety Inventory (STAI) and Korean-Barratt Impulsiveness Scale (BIS). Results: Immunoglobulin G antibodies were found in 21 of the 155 suicide attempters and in 8 of the 135 controls (p=0.011). The Toxoplasma-seropositive suicide attempters had a higher HAMD score on the depressed mood and feeling of guilt subscales and a higher total score than the seronegative suicide attempters. T. gondii seropositive status was associated with higher C-SSRS in the severity and lethality subscales. T. gondii IgG seropositivity was significantly associated with higher STAI-X1 scores in the suicide attempters group. Conclusion: Suicide attempters showed higher seroprevalence of T. gondii than healthy controls. Among the suicide attempters, the T. gondii seropositive and seronegative groups showed several differences in the aspects of suicide. These results suggested a significant association between T. gondii infection and psychiatric problems in suicidality.

Tagged: anxiety, depression, impulsive behavior, infection, suicide, Toxoplasma

Behavior Mental health

Toxoplasma gondii infection and common mental disorders in the Finnish general population

January 3, 2017
Suvisaari, J., Torniainen-Holm, M., Lindgren, M., Harkanen, T., Yolken, R. H.
Journal of Affective Disorders 2017; 223: 20-25

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Objective: We investigated whether T. gondii seropositivity is associated with 12-month depressive, anxiety and alcohol use disorders and current depressive symptoms and whether inflammation, measured by C-reactive protein (CRP) level, explains these associations. Method: Health 2000 study (BRIF8901), conducted in years 2000-2001, is based on a nationally representative sample of Finns aged 30 and above, with 7112 participants and 88.6% response rate. DSM-IV depressive, anxiety and alcohol use disorders were assessed with the Composite International Diagnostic Interview and depressive symptoms with the Beck Depressive Inventory (BDI-21). We used logistic regression to investigate the association of T. gondii seropositivity with mental disorders and linear regression with BDI-21 scores. Results: T. gondii seroprevalence was significantly associated with 12-month generalized anxiety disorder but not with other anxiety, depressive or alcohol use disorders. T. gondii seropositivity was associated with higher BDI-21 scores (beta 0.56, 95% CI 0.12-1.00, P = 0.013) and with having a comorbid depressive and anxiety disorder (OR 1.86, 95% CI 1.16-2.97, P = 0.010). Higher CRP levels were associated with these outcomes and with T. gondii seropositivity, but adjusting for CRP did not change the effect of T. gondii seropositivity. Limitations: Cross-sectional study design with no information on the timing of T. gondii infection. Conclusion: T. gondii seropositivity is associated with generalized anxiety disorder, depressive symptoms and comorbid depressive and anxiety disorders, which is not mediated by inflammation.

Tagged: adults, aggression, alcohol use disorders, anxiety, anxiety disorders, association, burden, c-reactive protein, depression, depressive disorders, generalized anxiety disorder, health, metaanalysis, mood, Schizophrenia, Toxoplasma gondii

Mental health

The “psychomicrobiotic”: Targeting microbiota in major psychiatric disorders: A systematic review

January 9, 2015
Fond, G., Boukouaci, W., Chevalier, G., Regnault, A., Eberl, G., Hamdani, N., Dickerson, F., Macgregor, A., Boyer, L., Dargel, A., Oliveira, J., Tamouza, R., Leboyer, M.
Pathologie Biologie 2015; 63: 35-42

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The gut microbiota is increasingly considered as a symbiotic partner in the maintenance of good health. Metagenomic approaches could help to discover how the complex gut microbial ecosystem participates in the control of the host's brain development and function, and could be relevant for future therapeutic developments, such as probiotics, prebiotics and nutritional approaches for psychiatric disorders. Previous reviews focused on the effects of microbiota on the central nervous system in in vitro and animal studies. The aim of the present review is to synthetize the current data on the association between microbiota dysbiosis and onset and/or maintenance of major psychiatric disorders, and to explore potential therapeutic opportunities targeting microbiota dysbiosis in psychiatric patients. (C) 2014 Elsevier Masson SAS. All rights reserved.

Tagged: antibiotic-associated diarrhea, anxiety, autism, bipolar disorder, clostridium-difficile infection, gut-brain axis, high-fat diet, human fecal microbiota, intestinal microbiota, irritable-bowel-syndrome, microbiota dysbiosis, probiotic, regressive autism, Schizophrenia, Toxoplasma gondii

Mental health Reviews

The role of parasites and pathogens in influencing generalised anxiety and predation-related fear in the mammalian central nervous system

October 12, 2012
Kaushik, M., Lamberton, P.H.L., Webster, J.P.
Hormones and Behavior 2012; 62: 191-201

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This article is part of a Special Issue "Neuroendocrine-Immune Axis in Health and Disease." Behavioural and neurophysiological traits and responses associated with anxiety and predation-related fear have been well documented in rodent models. Certain parasites and pathogens which rely on predation for transmission appear able to manipulate these, often innate, traits to increase the likelihood of their life-cycle being completed. This can occur through a range of mechanisms, such as alteration of hormonal and neurotransmitter communication and/or direct interference with the neurons and brain regions that mediate behavioural expression. Whilst some post-infection behavioural changes may reflect 'general sickness' or a pathological by-product of infection, others may have a specific adaptive advantage to the parasite and be indicative of active manipulation of host behaviour. Here we review the key mechanisms by which anxiety and predation-related fears are controlled in mammals, before exploring evidence for how some infectious agents may manipulate these mechanisms. The protozoan Toxoplasma gondii, the causative agent of toxoplasmosis, is focused on as a prime example. Selective pressures appear to have allowed this parasite to evolve strategies to alter the behaviour in its natural intermediate rodent host. Latent infection has also been associated with a range of altered behavioural profiles, from subtle to severe, in other secondary host species including humans. In addition to enhancing our knowledge of the evolution of parasite manipulation in general, to further our understanding of how and when these potential changes to human host behaviour occur, and how we may prevent or manage them, it is imperative to elucidate the associated mechanisms involved

Tagged: altered host behavior, anxiety, bacillus-calmette-guerin, c-reactive protein, central-nervous-system, depressive-like behavior, Dopamine, elevated plus-maze, endogenous kynurenic acid, helminth, male norway rats, mammal, obsessive-compulsive disorder, predation, protozoa, rodent, serotonin, toxocara-canis larvae, Toxoplasma gondii, toxoplasma gondii infection

Mental health

Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

anxiety

Latent toxoplasmosis and psychiatric symptoms – A role of tryptophan metabolism?

The association between suicide attempts and Toxoplasma gondii infection

Toxoplasma gondii infection and common mental disorders in the Finnish general population

The “psychomicrobiotic”: Targeting microbiota in major psychiatric disorders: A systematic review

The role of parasites and pathogens in influencing generalised anxiety and predation-related fear in the mammalian central nervous system