psychiatric-disorders

Toxoplasma gondii: Biological parameters of the connection to schizophrenia

February 12, 2018
Xiao, J. C. ,Prandovszky, E. , Kannan,G., Pletnikov, M. V. Dickerson, ,F. , Severance , E. G., Yolken, R. H.
Schizophrenia Bulletin 2018; 44: 983-992

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It is increasingly evident that the brain is not truly an immune privileged site and that cells of the central nervous system are sensitive to the inflammation generated when the brain is fighting off infection. Among the many microorganisms that have access to the brain, the apicomplexan protozoan Toxoplasma gondii has been one of the most studied. This parasite has been associated with many neuropsychiatric disorders including schizophrenia. This article provides a comprehensive review of the status of Toxoplasma research in schizophrenia. Areas of interest include (1) the limitations and improvements of immune-based assays to detect these infections in humans, (2) recent discoveries concerning the schizophrenia-Toxoplasma association, (3) findings of Toxoplasma neuropathology in animal models related to schizophrenia pathogenesis, (4) interactions of Toxoplasma with the host genome, (5) gastrointestinal effects of Toxoplasma infections, and (6) therapeutic intervention of Toxoplasma infections.

Tagged: attempts, bipolar disorder, complement c1q, congenital toxoplasmosis, immune activation, infection, microorganism, molecular-mechanisms, murine toxoplasmosis, pathogenesis, psychiatric-disorders, risk factors, suicide, tissue cyst formation

Mental health

The association between immune markers and recent suicide attempts in patients with serious mental illness: A pilot study

March 23, 2017
Dickerson, F., Adamos, M., Katsafanas, E., Khushalani, S., Origoni, A., Savage, C., Schweinfurth, L., Stallings, C., Sweeney, K., Alaedini, A., Uhde, M., Severance, E., Wilcox, H. C., Yolken, R.
Psychiatry Research 2017;255:8-12

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Previous studies have identified elevations in markers of gastrointestinal inflammation in schizophrenia and mood disorders but studies have not measured the association between these markers and recent suicide attempts. We assessed 210 patients receiving treatment for schizophrenia, bipolar disorder, or major depression. We employed the Columbia Suicide Severity Rating Scale to identify recent and lifetime suicide attempts (actual, aborted, and interrupted). Psychiatric participants and a control group of 72 individuals without a psychiatric disorder had a blood sample drawn from which were measured specific markers of gastrointestinal inflammation and also C-Reactive protein (CRP). A total of 20 (10%) of psychiatric participants had a suicide attempt in the previous one month and 95 (45%) an attempt during their lifetime but not in the previous one month. The recent attempters had significantly elevated levels of antibodies to yeast mannan from Saccharomyces cerevisiae (ASCA), the food antigen gliadin, and bacterial lipopolysaccharide (LPS) compared with the non-psychiatric group when adjusting for demographic and clinical variables. These markers were not elevated in individuals with a past, but not recent, suicide attempt history. Our study indicates that there is evidence of gastrointestinal inflammation in some individuals who have had a recent suicide attempt.

Tagged: activation, attempted, biomarkers, bipolar disorder, celiac-disease, gastrointestinal, inflammation, inflammatory-bowel-disease, metaanalysis, psychiatric-disorders, rating-scale, Schizophrenia, sensitivity, suicide, Toxoplasma gondii

Mental health

Hepatitis C virus antibody titers associated with cognitive dysfunction in an asymptomatic community-based sample

May 29, 2016
Ibrahim, I., Salah, H., El Sayed, H., Mansour, H., Eissa, A., Wood, J., Fathi, W., Tobar, S., Gur, R. C., Gur, R. E., Dickerson, F., Yolken, R. H., El Bahaey, W., Nimgaonkar, V.
Journal of Clinical and Experimental Neuropsychology 2016; 38: 861-868

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Background: Hepatitis C virus (HCV) infection is associated with cognitive dysfunction in clinic-based studies. The risk could be attributed to factors such as antiviral medications, substance abuse, or coincidental infection. Aim: The aim was to evaluate cognitive function in relation to HCV antibody titers in a community-based sample of asymptomatic individuals at low risk for substance abuse. Method: Adults were ascertained from a community in Mansoura, Egypt, where HCV is endemic (n = 258). Cognitive performance was evaluated using the Arabic version of the Penn Computerized Neurocognitive Battery. Substance abuse and psychopathology were also assessed. Antibodies to HCV and Toxoplasma gondii (TOX), a common protozoan that can affect cognition, were estimated using serological IgG assays. Results: The prevalence of HCV and TOX infection was 17.6% and 52.9%, respectively. HCV antibody titers were significantly associated with worse function in four cognitive tests for accuracy and three tests for speed, after adjusting for covariates (p <.05, beta coefficients, 2.1-3.2). TOX antibody titers were associated with impaired accuracy in one test. Conclusions: The association between HCV antibody titers and cognitive impairment is not mediated by antiviral treatment or substance abuse in this sample. Whether HCV has a causal role in the cognitive dysfunction should be investigated.

Tagged: cognition, computerized neurocognitive battery, egypt, Epidemiology, hepatitis c virus, impairment, liver-disease, prevalence, psychiatric-disorders, quality of life, risk factors, Toxoplasma, toxoplasma gondii infection, united-states

Cognitive functions

The influence of latent toxoplasmosis on women’s reproductive function: four cross-sectional studies

January 8, 2015
Kankova, S., Flegr, J., Calda, P.
Folia Parasitologica 2015; 62:

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Several studies have investigated the association between infection with Toxoplasma gondii (Nicolle et Manceaux, 1908), pregnancy and fertility, but the results of studies focused on the fertility are rather ambiguous. Here we report results of four new cross-sectional studies. The studies were performed in the General University Hospital, Prague (study A with n = 1 165, and study C with n = 317), in private clinics of the Centre of Reproductive Medicine, Prague (study B with n = 1 016), and in a population of Czech and Slovak volunteers from the Facebook page 'Guinea Pigs' willing to participate in various basic science studies (study D with n = 524). In studies A and B, the clinical records were used to assess the fertility problems, whereas in studies C and D, the women were asked to rate their fertility problems using a six-point scale. Pregnant T. gondii-infected women were older than T. gondii-free women (study A: 33.1 vs 31.2, P < 0.001; study B: 30.6 vs 29.6, P = 0.012) and more often used assisted reproductive technology to conceive (study A: 17.2% vs 12.4%, P = 0.041; study B: 13.4% vs 9.2%, P = 0.317). Pregnant T. gondii-infected primiparous women were older than T. gondii-free primiparas (study A: 31.1 vs 29.5, P < 0.001; study B: 29.7 vs 28.9, P = 0.064) and more often used assisted reproductive technology to conceive (study A: 24.7% vs 14.4%, P = 0.010; study B: 15.9% vs 15.5%, P = 0.888). T. gondii-infected women reported to take a longer time to conceive than T. gondii-free women (P = 0.015). They also claimed to have more fertility problems than T. gondii-free women (P < 0.0001). Our results suggest that 'asymptomatic' latent toxoplasmosis could be a more serious source of fertility problems and health-associated burden than more severe but far rarer congenital toxoplasmosis.

Tagged: age, asymptomatic toxoplasmosis, behavioral-changes, gender differences, gondii, hypothesis, infertility, manipulation hypothesis, mice, Parasite, psychiatric-disorders, Schizophrenia, sex ratio, testosterone, Toxoplasma gondii

Reproduction

Relation of Schizophrenia Prevalence to Latitude, Climate, Fish Consumption, Infant Mortality, and Skin Color: A Role for Prenatal Vitamin D Deficiency and Infections?

October 26, 2009
Kinney, D. K., Teixeira, P., Hsu, D., Napoleon, S. C., Crowley, D. J., Miller, A., Hyman, W., Huang, E.
Schizophrenia Bulletin 2009; 35: 582-595

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Previous surveys found a large (> 10-fold) variation in schizophrenia prevalence at different geographic sites and a tendency for prevalence to increase with latitude. We conducted meta-analyses of prevalence studies to investigate whether these findings pointed to underlying etiologic factors in schizophrenia or were the result of methodological artifacts or the confounding of sites' latitude with level of healthcare at those sites. We found that these patterns were still present after controlling for an index of healthcare-025EFinfant mortality-025EFand focusing on 49 studies that used similar diagnostic and ascertainment methods. The tendencies for schizophrenia prevalence to increase with both latitude and colder climate were still large and significant and present on several continents. The increase in prevalence with latitude was greater for groups with low fish consumption, darker skin, and higher infant mortality-025EFconsistent with a role of prenatal vitamin D deficiency in schizophrenia. Previous research indicates that poor prenatal healthcare and nutrition increase risk for schizophrenia within the same region. These adverse conditions are more prevalent in developing countries concentrated near the equator, but schizophrenia prevalence is lowest at sites near the equator. This suggests that schizophrenia-producing environmental factors associated with higher latitude may be so powerful they overwhelm protective effects of better healthcare in industrialized countries. The observed patterns of correlations of risk factors with prevalence are consistent with an etiologic role for prenatal vitamin D deficiency and exposure to certain infectious diseases. Research to elucidate environmental factors that underlie variations in schizophrenia prevalence deserves high priority.

Tagged: bipolar disorder, birth, Epidemiology, etiology, family-history, geography, immune function, influenza, mental-health survey, prenatal, psychiatric-disorders, Risk factor, Toxoplasma gondii, urban-community

Mental health

Are some cases of psychosis caused by microbial agents? A review of the evidence

October 26, 2008
Yolken RH, Torrey EF
Molecular Psychiatry 2008; 13: 470-479

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The infectious theory of psychosis, prominent early in the twentieth century, has recently received renewed scientific support. Evidence has accumulated that schizophrenia and bipolar disorder are complex diseases in which many predisposing genes interact with one or more environmental agents to cause symptoms. The protozoan Toxoplasma gondii and cytomegalovirus are discussed as examples of infectious agents that have been linked to schizophrenia and in which genes and infectious agents interact. Such infections may occur early in life and are thus consistent with neurodevelopmental as well as genetic theories of psychosis. The outstanding questions regarding infectious theories concern timing and causality. Attempts are underway to address the former by examining sera of individuals prior to the onset of illness and to address the latter by using antiinfective medications to treat individuals with psychosis. The identification of infectious agents associated with the etiopathogenesis of schizophrenia might lead to new methods for the diagnosis, treatment and prevention of this disorder.

Tagged: bipolar disorder, central-nervous-system, congenital cytomegalovirus-infection, cytomegalovirus, environmental, genetic, genetic polymorphisms, immunodeficiency-virus, infectious, necrosis-factor-alpha, psychiatric-disorders, Schizophrenia, toxoplasma gondii infection, toxoplasmosis, viral-infection, virus-infection

Mental health

Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

psychiatric-disorders

Toxoplasma gondii: Biological parameters of the connection to schizophrenia

The association between immune markers and recent suicide attempts in patients with serious mental illness: A pilot study

Hepatitis C virus antibody titers associated with cognitive dysfunction in an asymptomatic community-based sample

The influence of latent toxoplasmosis on women’s reproductive function: four cross-sectional studies

Relation of Schizophrenia Prevalence to Latitude, Climate, Fish Consumption, Infant Mortality, and Skin Color: A Role for Prenatal Vitamin D Deficiency and Infections?

Are some cases of psychosis caused by microbial agents? A review of the evidence