Toxoplasma gondii, Suicidal Behavior, and Intermediate Phenotypes for Suicidal Behavior
AuthorPostolache, Teodor T
Hoisington, Andrew J
Lowry, Christopher A
Okusaga, Olaoluwa O
Brenner, Lisa A
JournalFrontiers in Psychiatry
PublisherFrontiers Media S.A.
MetadataShow full item record
AbstractWithin the general literature on infections and suicidal behavior, studies on Toxoplasma gondii (T. gondii) occupy a central position. This is related to the parasite's neurotropism, high prevalence of chronic infection, as well as specific and non-specific behavioral alterations in rodents that lead to increased risk taking, which are recapitulated in humans by T. gondii's associations with suicidal behavior, as well as trait impulsivity and aggression, mental illness and traffic accidents. This paper is a detailed review of the associations between T. gondii serology and suicidal behavior, a field of study that started 15 years ago with our publication of associations between T. gondii IgG serology and suicidal behavior in persons with mood disorders. This "legacy" article presents, chronologically, our primary studies in individuals with mood disorders and schizophrenia in Germany, recent attempters in Sweden, and in a large cohort of mothers in Denmark. Then, it reviews findings from all three meta-analyses published to date, confirming our reported associations and overall consistent in effect size [ranging between 39 and 57% elevation of odds of suicide attempt in T. gondii immunoglobulin (IgG) positives]. Finally, the article introduces certain links between T. gondii and biomarkers previously associated with suicidal behavior (kynurenines, phenylalanine/tyrosine), intermediate phenotypes of suicidal behavior (impulsivity, aggression) and state-dependent suicide risk factors (hopelessness/dysphoria, sleep impairment). In sum, an abundance of evidence supports a positive link between suicide attempts (but not suicidal ideation) and T. gondii IgG (but not IgM) seropositivity and serointensity. Trait impulsivity and aggression, endophenotypes of suicidal behavior have also been positively associated with T. gondii seropositivity in both the psychiatrically healthy as well as in patients with Intermittent Explosive Disorder. Yet, causality has not been demonstrated. Thus, randomized interventional studies are necessary to advance causal inferences and, if causality is confirmed, to provide hope that an etiological treatment for a distinct subgroup of individuals at an increased risk for suicide could emerge.
Rights/TermsCopyright © 2021 Postolache, Wadhawan, Rujescu, Hoisington, Dagdag, Baca-Garcia, Lowry, Okusaga and Brenner.
Identifier to cite or link to this itemhttp://hdl.handle.net/10713/16109
- Toxoplasma gondii immunoglobulin G antibodies and nonfatal suicidal self-directed violence.
- Authors: Zhang Y, Träskman-Bendz L, Janelidze S, Langenberg P, Saleh A, Constantine N, Okusaga O, Bay-Richter C, Brundin L, Postolache TT
- Issue date: 2012 Aug
- "Latent" infection with Toxoplasma gondii: association with trait aggression and impulsivity in healthy adults.
- Authors: Cook TB, Brenner LA, Cloninger CR, Langenberg P, Igbide A, Giegling I, Hartmann AM, Konte B, Friedl M, Brundin L, Groer MW, Can A, Rujescu D, Postolache TT
- Issue date: 2015 Jan
- Toxoplasma gondii, the Immune System, and Suicidal Behavior.
- Authors: Dwivedi Y, Okusaga O, Postolache TT
- Issue date: 2012
- Toxoplasma gondii antibody titers and history of suicide attempts in patients with schizophrenia.
- Authors: Okusaga O, Langenberg P, Sleemi A, Vaswani D, Giegling I, Hartmann AM, Konte B, Friedl M, Groer MW, Yolken RH, Rujescu D, Postolache TT
- Issue date: 2011 Dec
- Toxoplasma gondii infection: relationship with aggression in psychiatric subjects.
- Authors: Coccaro EF, Lee R, Groer MW, Can A, Coussons-Read M, Postolache TT
- Issue date: 2016 Mar
Showing items related by title, author, creator and subject.
The relationship between trauma exposure and psychiatric hospitalization for suicide ideation or suicide attempt among patients admitted to a military treatment settingRyan, A.T.; Daruwala, S.E.; Perera, K.U. (MDPI AG, 2020)Suicide attempts and psychiatric hospitalization represent the final outcomes of a complex dynamical system of interacting factors that influence a particular individual's likelihood of engaging in suicidal behavior, as well as their ability to seek help prior to acting upon suicidal impulses. This study examined the association between different types of lifetime trauma exposure and the likelihood of psychiatric hospitalization following a suicide attempt (SA) rather than suicidal ideation (SI) alone. Electronic medical records for 1100 U.S. military service members and their dependents admitted to a military psychiatric inpatient setting for SA or SI were reviewed for documented lifetime trauma exposure history. Findings indicated that exposure to at least one childhood trauma of any type, and childhood neglect in particular, increased the likelihood that an individual would be hospitalized for SA rather than SI. Exploratory gender-stratified analyses demonstrated that childhood neglect, childhood sexual abuse, and adulthood traumatic loss may be linked with the likelihood of being hospitalized for SA. These findings demonstrate the importance of developing more detailed and nuanced conception of factors known to be associated with suicide as their effects may depend on details of their timing and nature, as well as their interactions with other systems. Copyright 2020 by the authors.
Aspiring to a Zero Suicide Mindset at Work: Research-based U.S. National Guidelines for Suicide Prevention and PostventionMortali, Maggie G.; Frey, Jodi J; Spencer-Thomas, Sally (2020-12-14)This presentation was presented as part of the 2020 Work and Family Researchers Network (WFRN) Annual Conference. The presenters represent leaders in the field of workplace suicide prevention and all worked on developing and disseminating the U.S. National Guidelines for Workplace Suicide Prevention which are described in this presentation. At the end of this presentation, participants will be able to: 1) list reasons why suicide prevention is a workplace health and safety priority; 2) describe the essential elements of the National Guidelines for Workplace Suicide Prevention; and 3) take at least one action step towards building a sustained and comprehensive strategy for their workplace or professional association.
Firearm-related internet searches as a correlate of future firearm suicides: Cross-correlation analyses of monthly Google search volumes and method-specific suicide rates in the United StatesLee, Joo Young; Pham, Angeline; Wong, Jonathan; Deng, Zhuoheng (Elsevier, 2021-07-01)Background: No previous study has investigated correlations between monthly Google search volumes (MGSVs) of suicide-related search terms and suicide-method specific monthly suicide rates (MSRs). This study examined if the trends in MGSVs of suicide-related terms preceded the variations in method-specific MSRs. Methods: MGSVs of 97 candidate suicide-related terms were obtained by averaging 10 timeseries data per term retrieved from Google Trends. Robust time-series analysis methods were applied to MGSVs and firearm-, poisoning-, and asphyxiation-specific MSRs in the United States between 2004 and 2017. Cross-correlation coefficients between MGSVs and methodspecific MSRs were calculated at lags of −3 to −1 (months). In the main analysis, the Benjamini-Hochberg procedure was applied to determine significant correlations while minimizing falsepositive findings. Afterwards, a sensitivity analysis identified the cross-correlations reproducible in two different time spans. Results: Fifty-six search terms with no invalid MGSV data were analyzed. MGSVs of 14 terms correlated with firearm-, poisoning-, or asphyxiation-specific MSRs in one or more lags. In the sensitivity analysis, two terms consistently showed significant positive cross-correlations: gun suicide (with firearm-specific suicides; lag -3) and “laid off” (with poisoning- and asphyxiationspecific suicides; lag -2). Limitations: Age- or gender-specific search volumes, lags outside the 1- to 3-month range, non-English searches, and confounding factors of MGSV and MSR were not explored. Conclusions: MGSVs of one firearm-related term (gun suicide) correlated with future firearmspecific MSRs. MGSVs of one method-neutral term (“laid off”) correlated with future poisoning- and asphyxiation-specific MSRs. These terms may be incorporated in novel nowcasting or predictive models for method-specific suicides. © 2021 The Author(s)