1
|
Song G, Zhao Q, Chen H, Li M, Zhang Z, Qu Z, Yang C, Lin X, Ma W, Standlee CR. Toxoplasma gondii seropositivity and cognitive functioning in older adults: an analysis of cross-sectional data of the National Health and Nutrition Examination Survey 2011-2014. BMJ Open 2024; 14:e071513. [PMID: 38448067 PMCID: PMC10916126 DOI: 10.1136/bmjopen-2022-071513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 02/14/2024] [Indexed: 03/08/2024] Open
Abstract
OBJECTIVES This study sought to examine the relationship between Toxoplasma gondii seropositivity and cognitive function in older adults. DESIGN An observational cross-sectional study. SETTING The National Health and Nutrition Examination Survey (NHANES) study took place at participants' homes and mobile examination centres. PARTICIPANTS A total of 2956 older adults aged 60 and above from the NHANES from 2011 to 2014 were included in the study. Exposure of interest: participants had serum Toxoplasma gondii antibody analysed in the laboratory. A value>33 IU/mL was categorised as seropositive for Toxoplasma gondii infection; <27 IU/mL was categorised as seronegative for Toxoplasma gondii infection. PRIMARY AND SECONDARY OUTCOME MEASURES Cognitive tests included the Consortium to Establish a Registry for Alzheimer's Disease Word Learning subtest (CERAD-WL) for immediate and delayed memory, the Animal Fluency Test (AFT), and the Digit Symbol Substitution Test (DSST). RESULTS About half of the 2956 participants (mean age 70.0) were female (51.0%), non-Hispanic White (48.3%), and completed some college or above (48.3%). A total of 703 participants were positive for Toxoplasma gondii infection (23.8%). Adjusted linear regression showed that compared with participants with negative Toxoplasma gondii infection, those with positive Toxoplasma gondii infection had lower CERAD-WL immediate memory (beta (β) -0.16, 95% CI -0.25 to -0.07), CERAD-WL delayed memory (β -0.15, 95% CI -0.24 to -0.06), AFT (β -0.15, 95% CI -0.24 to -0.06), DSST (β -0.34, 95% CI -0.43 to -0.26), and global cognition (β -0.24, 95% CI -0.32 to -0.16) z-scores after controlling for the covariates. CONCLUSIONS Toxoplasma gondii seropositivity is associated with worse immediate and delayed verbal learning, language proficiency, executive functioning, processing speed, sustained attention, working memory, as well as global cognition in older adults. Public health measures aiming at preventing Toxoplasma gondii infection may help preserve cognitive functioning in older adults.
Collapse
Affiliation(s)
- Ge Song
- College of Sciences and Technology, University of Houston Downtown, Houston, Texas, USA
| | - Qingxia Zhao
- School of Nursing, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Hongyu Chen
- School of Nursing, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Meng Li
- Kentucky Department for Public Health, Infectious Disease Branch, Frankfort, Kentucky, USA
| | - Zeyu Zhang
- Institute for Hospital Management, Tsinghua University, Beijing, China
| | - Zhe Qu
- Department of Pediatric Respiratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Chao Yang
- University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Xuechun Lin
- Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Huazhong University of Science and Technology, Wuhan, China
| | - Weixia Ma
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | | |
Collapse
|
2
|
Rosado D, Intriago B, Loor E, Alcívar F, Avila J, Sotomayor M, Villacres L, Faytong-Haro M. Associations between Toxoplasma gondii seropositivity and psychopathological manifestations in schizophrenic patients: A single-center study from Ecuador. PLoS One 2024; 19:e0297523. [PMID: 38394236 PMCID: PMC10890741 DOI: 10.1371/journal.pone.0297523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 01/05/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND Schizophrenia, a complex neuropsychiatric disorder, is believed to be influenced by various factors including environmental exposures. A potential environmental factor is the infection by the obligate intracellular parasitic protozoan, Toxoplasma gondii which affects neurotransmitter levels, which could potentially exacerbate, trigger symptoms of schizophrenia or make them worst. OBJECTIVE To investigate the association between Toxoplasma gondii seropositivity and psychopathological presentation in persons with schizophrenia in Ecuador. METHODS This study was conducted at the Neuroscience Institute of Guayaquil, Ecuador. Among 368 inpatients, 104 were selected based on specific inclusion and exclusion criteria. Descriptive statistics captured patient characteristics and mental health outcomes. Logistic regression models estimated the effect of toxoplasmosis on various mental health outcomes, controlling for demographic and health-related variables. RESULTS 86.5% of participants were seropositive for toxoplasmosis. Toxoplasma-seropositive schizophrenic patients had a lower risk of depression but a significantly higher risk of disorientation. The most prevalent mental health outcomes were Language Impairments (70.2%) and Bizarre Behavior (76.0%). CONCLUSION Our findings suggest that Toxoplasma gondii seropositivity may have specific effects on mental functions in schizophrenic patients, particularly reducing the risk of depression but increasing the risk of disorientation. Further studies are required to clarify these associations and the potential underlying mechanisms.
Collapse
Affiliation(s)
- Diego Rosado
- School of Health, Universidad de Especialidades Espíritu Santo, Guayas, Samborondón, Ecuador
| | - Belen Intriago
- School of Health, Universidad de Especialidades Espíritu Santo, Guayas, Samborondón, Ecuador
| | - Evelyn Loor
- School of Health, Universidad de Especialidades Espíritu Santo, Guayas, Samborondón, Ecuador
| | - Flor Alcívar
- School of Health, Universidad de Especialidades Espíritu Santo, Guayas, Samborondón, Ecuador
| | - Jorge Avila
- Internal Medicine, Elizabeth’s Medical Center, Tufts University, St, Hospital, Boston, MA, United States of America
| | - Mario Sotomayor
- Gastroenterology Department, Hospital Universitario Puerta del Mar, Cadiz, Spain
| | - Larissa Villacres
- School of Health, Universidad de Especialidades Espíritu Santo, Guayas, Samborondón, Ecuador
| | - Marco Faytong-Haro
- Universidad Estatal de Milagro, Cdla. Universitaria “Dr. Rómulo Minchala Murillo”, Guayas, Milagro, Ecuador
- Laboratorio para Investigación para el Desarrollo del Ecuador, Guayas, Guayaquil, Ecuador
| |
Collapse
|
3
|
Godino A, Salery M, Durand-de Cuttoli R, Estill MS, Holt LM, Futamura R, Browne CJ, Mews P, Hamilton PJ, Neve RL, Shen L, Russo SJ, Nestler EJ. Transcriptional control of nucleus accumbens neuronal excitability by retinoid X receptor alpha tunes sensitivity to drug rewards. Neuron 2023; 111:1453-1467.e7. [PMID: 36889314 PMCID: PMC10164098 DOI: 10.1016/j.neuron.2023.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 12/06/2022] [Accepted: 02/07/2023] [Indexed: 03/09/2023]
Abstract
The complex nature of the transcriptional networks underlying addictive behaviors suggests intricate cooperation between diverse gene regulation mechanisms that go beyond canonical activity-dependent pathways. Here, we implicate in this process a nuclear receptor transcription factor, retinoid X receptor alpha (RXRα), which we initially identified bioinformatically as associated with addiction-like behaviors. In the nucleus accumbens (NAc) of male and female mice, we show that although its own expression remains unaltered after cocaine exposure, RXRα controls plasticity- and addiction-relevant transcriptional programs in both dopamine receptor D1- and D2-expressing medium spiny neurons, which in turn modulate intrinsic excitability and synaptic activity of these NAc cell types. Behaviorally, bidirectional viral and pharmacological manipulation of RXRα regulates drug reward sensitivity in both non-operant and operant paradigms. Together, this study demonstrates a key role for NAc RXRα in promoting drug addiction and paves the way for future studies of rexinoid signaling in psychiatric disease states.
Collapse
Affiliation(s)
- Arthur Godino
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Marine Salery
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Romain Durand-de Cuttoli
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Molly S Estill
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Leanne M Holt
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rita Futamura
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Caleb J Browne
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Philipp Mews
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Peter J Hamilton
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rachael L Neve
- Gene Delivery Technology Core, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Li Shen
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Scott J Russo
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Eric J Nestler
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| |
Collapse
|
4
|
Nessim J, Luna-Ramirez JC, Moreno-Gómez GA, Galvis-Soto DM, Gomez-Marin JE. Estimations of the number people with mental diseases associated with toxoplasmosis and identification of risk factors by continent. Psychiatry Res 2023; 323:115130. [PMID: 36913872 DOI: 10.1016/j.psychres.2023.115130] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/18/2023] [Accepted: 02/20/2023] [Indexed: 03/15/2023]
Abstract
Strong evidence exists based on metanalysis of the relationship between toxoplasmosis and many psychiatric diseases: schizophrenia, bipolar disorder, and suicidal behavior. Herein, we estimate the number of cases based on the attributable fraction due to toxoplasmosis on these diseases. The population attributable fraction of mental disease associated with toxoplasmosis was 20,4% for schizophrenia; 27,3% for bipolar disorder; and 0,29% for suicidal behavior (self-harm). The lower and upper estimated number of people with mental disease associated with toxoplasmosis was 4'816.491 and 5'564.407 for schizophrenia; 6'348.946 and 7'510.118,82 for bipolar disorder; and 24.310 and 28.151 for self-harm; for a global total lower estimated number of 11'189.748 and global total upper estimated number of 13'102.678 people with mental disease associated with toxoplasmosis for the year 2019. According to the prediction through the Bayesian model of risk factors for toxoplasmosis associated with mental disease, these varied in importance geographically; thus, in Africa, the most important risk factor was water contamination and in the European region, the cooking conditions of meats. Toxoplasmosis and mental health should be a research priority given the enormous potential impact of reducing this parasite in the general population.
Collapse
Affiliation(s)
- Jennifer Nessim
- Molecular Parasitology Group (GEPAMOL, for the term in Spanish), Biomedical Research Center, Faculty of Health Sciences, Universidad del Quindío, Armenia, Colombia
| | | | | | | | - Jorge E Gomez-Marin
- Molecular Parasitology Group (GEPAMOL, for the term in Spanish), Biomedical Research Center, Faculty of Health Sciences, Universidad del Quindío, Armenia, Colombia.
| |
Collapse
|
5
|
Carrillo GL, Su J, Cawley ML, Wei D, Gill SK, Blader IJ, Fox MA. Complement-dependent loss of inhibitory synapses on pyramidal neurons following Toxoplasma gondii infection. J Neurochem 2023:10.1111/jnc.15770. [PMID: 36683435 PMCID: PMC10363253 DOI: 10.1111/jnc.15770] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 01/06/2023] [Accepted: 01/15/2023] [Indexed: 01/24/2023]
Abstract
The apicomplexan parasite Toxoplasma gondii has developed mechanisms to establish a central nervous system infection in virtually all warm-blooded animals. Acute T. gondii infection can cause neuroinflammation, encephalitis, and seizures. Meanwhile, studies in humans, nonhuman primates, and rodents have linked chronic T. gondii infection with altered behavior and increased risk for neuropsychiatric disorders, including schizophrenia. These observations and associations raise questions about how this parasitic infection may alter neural circuits. We previously demonstrated that T. gondii infection triggers the loss of inhibitory perisomatic synapses, a type of synapse whose dysfunction or loss has been linked to neurological and neuropsychiatric disorders. We showed that phagocytic cells (including microglia and infiltrating monocytes) contribute to the loss of these inhibitory synapses. Here, we show that these phagocytic cells specifically ensheath excitatory pyramidal neurons, leading to the preferential loss of perisomatic synapses on these neurons and not those on cortical interneurons. Moreover, we show that infection induces an increased expression of the complement C3 gene, including by populations of these excitatory neurons. Infecting C3-deficient mice with T. gondii revealed that C3 is required for the loss of perisomatic inhibitory synapses. Interestingly, loss of C1q did not prevent the loss of perisomatic synapses following infection. Together, these findings provide evidence that T. gondii induces changes in excitatory pyramidal neurons that trigger the selective removal of inhibitory perisomatic synapses and provide a role for a nonclassical complement pathway in the remodeling of inhibitory circuits in the infected brain.
Collapse
Affiliation(s)
- Gabriela L. Carrillo
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Jianmin Su
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- School of Neuroscience, College of Science, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Mikel L. Cawley
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Derek Wei
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- School of Neuroscience, College of Science, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Simran K. Gill
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- Department of Psychology, Roanoke College, Salem, Virginia, 24153, USA
- NeuroSURF Program, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
| | - Ira J. Blader
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York, 14203, USA
| | - Michael A. Fox
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, 24016, USA
- School of Neuroscience, College of Science, Virginia Tech, Blacksburg, Virginia, 24061, USA
- Department of Biological Sciences, College of Science, Virginia Tech, Blacksburg, Virginia, 24061, USA
- Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, 24016, USA
| |
Collapse
|
6
|
Sánchez-Arcila JC, Jensen KDC. Forward Genetics in Apicomplexa Biology: The Host Side of the Story. Front Cell Infect Microbiol 2022; 12:878475. [PMID: 35646724 PMCID: PMC9133346 DOI: 10.3389/fcimb.2022.878475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
Forward genetic approaches have been widely used in parasitology and have proven their power to reveal the complexities of host-parasite interactions in an unbiased fashion. Many aspects of the parasite’s biology, including the identification of virulence factors, replication determinants, antibiotic resistance genes, and other factors required for parasitic life, have been discovered using such strategies. Forward genetic approaches have also been employed to understand host resistance mechanisms to parasitic infection. Here, we will introduce and review all forward genetic approaches that have been used to identify host factors involved with Apicomplexa infections, which include classical genetic screens and QTL mapping, GWAS, ENU mutagenesis, overexpression, RNAi and CRISPR-Cas9 library screens. Collectively, these screens have improved our understanding of host resistance mechanisms, immune regulation, vaccine and drug designs for Apicomplexa parasites. We will also discuss how recent advances in molecular genetics give present opportunities to further explore host-parasite relationships.
Collapse
Affiliation(s)
- Juan C. Sánchez-Arcila
- Department of Molecular and Cell Biology, University of California Merced, Merced, CA, United States
| | - Kirk D. C. Jensen
- Department of Molecular and Cell Biology, University of California Merced, Merced, CA, United States
- Health Science Research Institute, University of California, Merced, Merced, CA, United States
- *Correspondence: Kirk D. C. Jensen,
| |
Collapse
|
7
|
Gene-Environment Interactions in Schizophrenia: A Literature Review. Genes (Basel) 2021; 12:genes12121850. [PMID: 34946799 PMCID: PMC8702084 DOI: 10.3390/genes12121850] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 12/12/2022] Open
Abstract
Schizophrenia is a devastating mental illness with a strong genetic component that is the subject of extensive research. Despite the high heritability, it is well recognized that non-genetic factors such as certain infections, cannabis use, psychosocial stress, childhood adversity, urban environment, and immigrant status also play a role. Whenever genetic and non-genetic factors co-exist, interaction between the two is likely. This means that certain exposures would only be of consequence given a specific genetic makeup. Here, we provide a brief review of studies reporting evidence of such interactions, exploring genes and variants that moderate the effect of the environment to increase risk of developing psychosis. Discovering these interactions is crucial to our understanding of the pathogenesis of complex disorders. It can help in identifying individuals at high risk, in developing individualized treatments and prevention plans, and can influence clinical management.
Collapse
|
8
|
de Haan L, Sutterland AL, Schotborgh JV, Schirmbeck F, de Haan L. Association of Toxoplasma gondii Seropositivity With Cognitive Function in Healthy People: A Systematic Review and Meta-analysis. JAMA Psychiatry 2021; 78:1103-1112. [PMID: 34259822 PMCID: PMC8281022 DOI: 10.1001/jamapsychiatry.2021.1590] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
IMPORTANCE The parasite Toxoplasma gondii has been associated with behavioral alterations and psychiatric disorders. Studies investigating neurocognition in people with T gondii infection have reported varying results. To systematically analyze these findings, a meta-analysis evaluating cognitive function in healthy people with and without T gondii seropositivity is needed. OBJECTIVE To assess whether and to what extent T gondii seropositivity is associated with cognitive function in otherwise healthy people. DATA SOURCES A systematic search was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. A systematic search of PubMed, MEDLINE, Web of Science, PsycInfo, and Embase was performed to identify studies from database inception to June 7, 2019, that analyzed cognitive function among healthy participants with available data on T gondii seropositivity. Search terms included toxoplasmosis, neurotoxoplasmosis, Toxoplasma gondii, cognition disorder, neuropsychological, and psychomotor performance. STUDY SELECTION Studies that performed cognitive assessment and analyzed T gondii seroprevalence among otherwise healthy participants were included. DATA EXTRACTION AND SYNTHESIS Two researchers independently extracted data from published articles; if needed, authors were contacted to provide additional data. Quantitative syntheses were performed in predefined cognitive domains when 4 independent data sets per domain were available. Study quality, heterogeneity, and publication bias were assessed. MAIN OUTCOMES AND MEASURES Performance on neuropsychological tests measuring cognitive function. RESULTS The systematic search yielded 1954 records. After removal of 533 duplicates, an additional 1363 records were excluded based on a review of titles and abstracts. A total of 58 full-text articles were assessed for eligibility (including reference list screening); 45 articles were excluded because they lacked important data or did not meet study inclusion or reference list criteria. The remaining 13 studies comprising 13 289 healthy participants (mean [SD] age, 46.7 [16.0] years; 6586 men [49.6%]) with and without T gondii seropositivity were included in the meta-analysis. Participants without T gondii seropositivity had favorable functioning in 4 cognitive domains: processing speed (standardized mean difference [SMD], 0.12; 95% CI, 0.05-0.19; P = .001), working memory (SMD, 0.16; 95% CI, 0.06-0.26; P = .002), short-term verbal memory (SMD, 0.18; 95% CI, 0.09-0.27; P < .001), and executive functioning (SMD, 0.15; 95% CI, 0.01-0.28; P = .03). A meta-regression analysis found a significant association between older age and executive functioning (Q = 6.17; P = .01). Little suggestion of publication bias was detected. CONCLUSIONS AND RELEVANCE The study's findings suggested that T gondii seropositivity was associated with mild cognitive impairment in several cognitive domains. Although effect sizes were small, given the ubiquitous prevalence of this infection globally, the association with cognitive impairment could imply a considerable adverse effect at the population level. Further research is warranted to investigate the underlying mechanisms of this association.
Collapse
Affiliation(s)
- Lies de Haan
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Arjen L. Sutterland
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Jasper V. Schotborgh
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Frederike Schirmbeck
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Lieuwe de Haan
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| |
Collapse
|
9
|
Robinson N, Bergen SE. Environmental Risk Factors for Schizophrenia and Bipolar Disorder and Their Relationship to Genetic Risk: Current Knowledge and Future Directions. Front Genet 2021; 12:686666. [PMID: 34262598 PMCID: PMC8273311 DOI: 10.3389/fgene.2021.686666] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 05/20/2021] [Indexed: 12/16/2022] Open
Abstract
Schizophrenia (SZ) and bipolar disorder (BD) are severe psychiatric disorders which result from complex interplay between genetic and environmental factors. It is well-established that they are highly heritable disorders, and considerable progress has been made identifying their shared and distinct genetic risk factors. However, the 15-40% of risk that is derived from environmental sources is less definitively known. Environmental factors that have been repeatedly investigated and often associated with SZ include: obstetric complications, infections, winter or spring birth, migration, urban living, childhood adversity, and cannabis use. There is evidence that childhood adversity and some types of infections are also associated with BD. Evidence for other risk factors in BD is weaker due to fewer studies and often smaller sample sizes. Relatively few environmental exposures have ever been examined for SZ or BD, and additional ones likely remain to be discovered. A complete picture of how genetic and environmental risk factors confer risk for these disorders requires an understanding of how they interact. Early gene-by-environment interaction studies for both SZ and BD often involved candidate genes and were underpowered. Larger samples with genome-wide data and polygenic risk scores now offer enhanced prospects to reveal genetic interactions with environmental exposures that contribute to risk for these disorders. Overall, although some environmental risk factors have been identified for SZ, few have been for BD, and the extent to which these account for the total risk from environmental sources remains unknown. For both disorders, interactions between genetic and environmental risk factors are also not well understood and merit further investigation. Questions remain regarding the mechanisms by which risk factors exert their effects, and the ways in which environmental factors differ by sex. Concurrent investigations of environmental and genetic risk factors in SZ and BD are needed as we work toward a more comprehensive understanding of the ways in which these disorders arise.
Collapse
Affiliation(s)
| | - Sarah E. Bergen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
10
|
Retinoid X Receptor α Regulates DHA-Dependent Spinogenesis and Functional Synapse Formation In Vivo. Cell Rep 2021; 31:107649. [PMID: 32433958 DOI: 10.1016/j.celrep.2020.107649] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 02/01/2020] [Accepted: 04/22/2020] [Indexed: 12/23/2022] Open
Abstract
Coordinated intracellular and extracellular signaling is critical to synapse development and functional neural circuit wiring. Here, we report that unesterified docosahexaenoic acid (DHA) regulates functional synapse formation in vivo via retinoid X receptor α (Rxra) signaling. Using Rxra conditional knockout (cKO) mice and virus-mediated transient gene expression, we show that endogenous Rxra plays important roles in regulating spinogenesis and excitatory synaptic transmission in cortical pyramidal neurons. We further show that the effects of RXRA are mediated through its DNA-binding domain in a cell-autonomous and reversible manner. Moreover, unesterified DHA increases spine formation and excitatory synaptic transmission in vivo in an Rxra-dependent fashion. Rxra cKO mice generally behave normally but show deficits in behavior tasks associated with social memory. Together, these results demonstrate that unesterified DHA signals through RXRA to regulate spinogenesis and functional synapse formation, providing insight into the mechanism through which DHA promotes brain development and cognitive function.
Collapse
|
11
|
Lori A, Avramopoulos D, Wang AW, Mulle J, Massa N, Duncan EJ, Powers A, Conneely K, Gillespie CF, Jovanovic T, Ressler KJ, Pearce BD. Polygenic risk scores differentiate schizophrenia patients with toxoplasma gondii compared to toxoplasma seronegative patients. Compr Psychiatry 2021; 107:152236. [PMID: 33721583 DOI: 10.1016/j.comppsych.2021.152236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 01/28/2021] [Accepted: 02/12/2021] [Indexed: 11/28/2022] Open
Abstract
Schizophrenia (SCZ) is an etiologically heterogeneous disease with genetic and environmental risk factors (e.g., Toxoplasma gondii infection) differing among affected individuals. Distinguishing such risk factors may point to differences in pathophysiological pathways and facilitate the discovery of individualized treatments. Toxoplasma gondii (TOXO) has been implicated in increasing the risk of schizophrenia. To determine whether TOXO-positive individuals with SCZ have a different polygenic risk burden than uninfected people, we applied the SCZ polygenic risk score (SCZ-PRS) derived from the Psychiatric GWAS Consortium separately to the TOXO-positive and TOXO-negative subjects with the diagnosis of SCZ as the outcome variable. The SCZ-PRS does not include variants in the major histocompatibility complex. Of 790 subjects assessed for TOXO, the 662 TOXO-negative subjects (50.8% with SCZ) reached a Bonferroni corrected significant association (p = 0.00017, R2 = 0.023). In contrast, the 128 TOXO-positive individuals (53.1% with SCZ) showed no significant association (p = 0.354) for SCZ-PRS and had a much lower R2 (R2 = 0.007). To account for Type-2 error in the TOXO-positive dataset, we performed a random sampling of the TOXO-negative subpopulation (n = 130, repeated 100 times) to simulate equivalent power between groups: the p-value was <0.05 for SCZ-PRS 55% of the time but was rarely (6% of the time) comparable to the high p-value of the seropositive group at p > 0.354. We found intriguing evidence that the SCZ-PRS predicts SCZ in TOXO-negative subjects, as expected, but not in the TOXO-positive individuals. This result highlights the importance of considering environmental risk factors to distinguish a subgroup with independent or different genetic components involved in the development of SCZ.
Collapse
Affiliation(s)
- Adriana Lori
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, 101 Woodruff Circle, GA 30322, USA
| | | | - Alex W Wang
- Dept. of Epidemiology, Rollins School of Public Health; 1518 Clifton Rd., Atlanta, GA 30322, USA; Philadelphia College of Osteopathic Medicine, Suwanee, GA 30024, USA
| | - Jennifer Mulle
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - Nicholas Massa
- Dept. of Epidemiology, Rollins School of Public Health; 1518 Clifton Rd., Atlanta, GA 30322, USA; Atlanta Veterans Affairs Health Care System, Decatur, GA 30033, USA
| | - Erica J Duncan
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, 101 Woodruff Circle, GA 30322, USA; Atlanta Veterans Affairs Health Care System, Decatur, GA 30033, USA
| | - Abigail Powers
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, 101 Woodruff Circle, GA 30322, USA
| | - Karen Conneely
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - Charles F Gillespie
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, 101 Woodruff Circle, GA 30322, USA
| | - Tanja Jovanovic
- University of Texas at Austin Dell Medical School, Austin, TX, USA
| | - Kerry J Ressler
- Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Brad D Pearce
- Dept. of Epidemiology, Rollins School of Public Health; 1518 Clifton Rd., Atlanta, GA 30322, USA.
| |
Collapse
|
12
|
Carrillo GL, Ballard VA, Glausen T, Boone Z, Teamer J, Hinkson CL, Wohlfert EA, Blader IJ, Fox MA. Toxoplasma infection induces microglia-neuron contact and the loss of perisomatic inhibitory synapses. Glia 2020; 68:1968-1986. [PMID: 32157745 PMCID: PMC7423646 DOI: 10.1002/glia.23816] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 12/17/2022]
Abstract
Infection and inflammation within the brain induces changes in neuronal connectivity and function. The intracellular protozoan parasite, Toxoplasma gondii, is one pathogen that infects the brain and can cause encephalitis and seizures. Persistent infection by this parasite is also associated with behavioral alterations and an increased risk for developing psychiatric illness, including schizophrenia. Current evidence from studies in humans and mouse models suggest that both seizures and schizophrenia result from a loss or dysfunction of inhibitory synapses. In line with this, we recently reported that persistent T. gondii infection alters the distribution of glutamic acid decarboxylase 67 (GAD67), an enzyme that catalyzes GABA synthesis in inhibitory synapses. These changes could reflect a redistribution of presynaptic machinery in inhibitory neurons or a loss of inhibitory nerve terminals. To directly assess the latter possibility, we employed serial block face scanning electron microscopy (SBFSEM) and quantified inhibitory perisomatic synapses in neocortex and hippocampus following parasitic infection. Not only did persistent infection lead to a significant loss of perisomatic synapses, it induced the ensheathment of neuronal somata by myeloid-derived cells. Immunohistochemical, genetic, and ultrastructural analyses revealed that these myeloid-derived cells included activated microglia. Finally, ultrastructural analysis identified myeloid-derived cells enveloping perisomatic nerve terminals, suggesting they may actively displace or phagocytose synaptic elements. Thus, these results suggest that activated microglia contribute to perisomatic inhibitory synapse loss following parasitic infection and offer a novel mechanism as to how persistent T. gondii infection may contribute to both seizures and psychiatric illness.
Collapse
Affiliation(s)
- Gabriela L. Carrillo
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, 2 Riverside Circle, Roanoke, VA 24016
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061
| | - Valerie A. Ballard
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, 2 Riverside Circle, Roanoke, VA 24016
- Roanoke Valley Governor’s School, Roanoke VA 24015
| | - Taylor Glausen
- Department of Microbiology and Immunology, University at Buffalo, Buffalo NY 14260
| | - Zack Boone
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, 2 Riverside Circle, Roanoke, VA 24016
- School of Neuroscience, Virginia Tech, Blacksburg, VA 24061
| | - Joseph Teamer
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, 2 Riverside Circle, Roanoke, VA 24016
- FBRI neuroSURF Program, Roanoke, VA 24016
| | - Cyrus L. Hinkson
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, 2 Riverside Circle, Roanoke, VA 24016
- Virginia Tech Carilion School of Medicine, Roanoke, VA 24016
| | | | - Ira J. Blader
- Department of Microbiology and Immunology, University at Buffalo, Buffalo NY 14260
| | - Michael A. Fox
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, 2 Riverside Circle, Roanoke, VA 24016
- School of Neuroscience, Virginia Tech, Blacksburg, VA 24061
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061
- Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016
| |
Collapse
|
13
|
Pong S, Karmacharya R, Sofman M, Bishop JR, Lizano P. The Role of Brain Microvascular Endothelial Cell and Blood-Brain Barrier Dysfunction in Schizophrenia. Complex Psychiatry 2020; 6:30-46. [PMID: 34883503 PMCID: PMC7673590 DOI: 10.1159/000511552] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 09/10/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Despite decades of research, little clarity exists regarding pathogenic mechanisms related to schizophrenia. Investigations on the disease biology of schizophrenia have primarily focused on neuronal alterations. However, there is substantial evidence pointing to a significant role for the brain's microvasculature in mediating neuroinflammation in schizophrenia. SUMMARY Brain microvascular endothelial cells (BMEC) are a central element of the microvasculature that forms the blood-brain barrier (BBB) and shields the brain against toxins and immune cells via paracellular, transcellular, transporter, and extracellular matrix proteins. While evidence for BBB dysfunction exists in brain disorders, including schizophrenia, it is not known if BMEC themselves are functionally compromised and lead to BBB dysfunction. KEY MESSAGES Genome-wide association studies, postmortem investigations, and gene expression analyses have provided some insights into the role of the BBB in schizophrenia pathophysiology. However, there is a significant gap in our understanding of the role that BMEC play in BBB dysfunction. Recent advances differentiating human BMEC from induced pluripotent stem cells (iPSC) provide new avenues to examine the role of BMEC in BBB dysfunction in schizophrenia.
Collapse
Affiliation(s)
- Sovannarath Pong
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Rakesh Karmacharya
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts, USA
| | - Marianna Sofman
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jeffrey R. Bishop
- Departments of Clinical and Experimental Pharmacology and Psychiatry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Paulo Lizano
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
14
|
Infection with Toxoplasma gondii increases the risk of psychiatric disorders in Taiwan: a nationwide population-based cohort study. Parasitology 2020; 147:1577-1586. [PMID: 32729456 DOI: 10.1017/s0031182020001183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This study aimed to evaluate associations between toxoplasmosis and psychiatric disorders in Taiwan based on the National Health Insurance Research Database, Taiwan (1997-2013). Patients newly diagnosed with toxoplasmosis formed the case group (n = 259), and the control group included propensity-score matched patients without toxoplasmosis (n = 1036). The primary outcome was incidence of psychiatric disorders. Cox proportional hazards regression and stratified analyses were performed to examine risk of developing specific psychiatric disorders between patients with and without toxoplasmosis. Patients with toxoplasmosis had significantly higher incidence of psychiatric disorders than those without toxoplasmosis (P = 0.016). A significant difference was found in numbers of psychiatric disorders between the two groups during 14 years of follow-up (log-rank P < 0.001). Those with toxoplasmosis had significantly higher risk of bipolar disorder [adjusted hazard ratio (aHR = 3.60, 95% confidence interval (CI) = 2.07, 7.26), depression (aHR = 4.94, 95% CI = 2.15, 11.80) and anxiety (aHR = 5.36, 95% CI = 2.98, 25.88), but no significant between-group differences were found for schizophrenia and other psychiatric disorders. In conclusion, the present nationwide population-based analysis revealed that Toxoplasma gondii infection in Taiwan significantly increases the risk for developing bipolar disorder, depression and anxiety, but not for schizophrenia and other psychiatric disorders.
Collapse
|
15
|
Zhao XY, Ewald SE. The molecular biology and immune control of chronic Toxoplasma gondii infection. J Clin Invest 2020; 130:3370-3380. [PMID: 32609097 PMCID: PMC7324197 DOI: 10.1172/jci136226] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Toxoplasma gondii is an incredibly successful parasite owing in part to its ability to persist within cells for the life of the host. Remarkably, at least 350 host species of T. gondii have been described to date, and it is estimated that 30% of the global human population is chronically infected. The importance of T. gondii in human health was made clear with the first reports of congenital toxoplasmosis in the 1940s. However, the AIDS crisis in the 1980s revealed the prevalence of chronic infection, as patients presented with reactivated chronic toxoplasmosis, underscoring the importance of an intact immune system for parasite control. In the last 40 years, there has been tremendous progress toward understanding the biology of T. gondii infection using rodent models, human cell experimental systems, and clinical data. However, there are still major holes in our understanding of T. gondii biology, including the genes controlling parasite development, the mechanisms of cell-intrinsic immunity to T. gondii in the brain and muscle, and the long-term effects of infection on host homeostasis. The need to better understand the biology of chronic infection is underscored by the recent rise in ocular disease associated with emerging haplotypes of T. gondii and our lack of effective treatments to sterilize chronic infection. This Review discusses the cell types and molecular mediators, both host and parasite, that facilitate persistent T. gondii infection. We highlight the consequences of chronic infection for tissue-specific pathology and identify open questions in this area of host-Toxoplasma interactions.
Collapse
|
16
|
Abstract
The onset of schizophrenia is usually in late adolescence or early adulthood. However, accumulating evidence has suggested that the disease condition is an outcome of gene-environment interactions that act in neural development during early life and adolescence. Some children who later develop schizophrenia have early developmental and educational and social challenges. Some patients with schizophrenia have an abundance of nonspecific neurologic soft signs and minor physical anomalies. Adolescence is a sensitive period of increased neuronal plasticity. It is important to consider early detection and intervention from the prodromal stage to early disease to prevent its devastating long-term consequences.
Collapse
|
17
|
Kępińska AP, Iyegbe CO, Vernon AC, Yolken R, Murray RM, Pollak TA. Schizophrenia and Influenza at the Centenary of the 1918-1919 Spanish Influenza Pandemic: Mechanisms of Psychosis Risk. Front Psychiatry 2020; 11:72. [PMID: 32174851 PMCID: PMC7054463 DOI: 10.3389/fpsyt.2020.00072] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 01/28/2020] [Indexed: 12/13/2022] Open
Abstract
Associations between influenza infection and psychosis have been reported since the eighteenth century, with acute "psychoses of influenza" documented during multiple pandemics. In the late 20th century, reports of a season-of-birth effect in schizophrenia were supported by large-scale ecological and sero-epidemiological studies suggesting that maternal influenza infection increases the risk of psychosis in offspring. We examine the evidence for the association between influenza infection and schizophrenia risk, before reviewing possible mechanisms via which this risk may be conferred. Maternal immune activation models implicate placental dysfunction, disruption of cytokine networks, and subsequent microglial activation as potentially important pathogenic processes. More recent neuroimmunological advances focusing on neuronal autoimmunity following infection provide the basis for a model of infection-induced psychosis, potentially implicating autoimmunity to schizophrenia-relevant protein targets including the N-methyl-D-aspartate receptor. Finally, we outline areas for future research and relevant experimental approaches and consider whether the current evidence provides a basis for the rational development of strategies to prevent schizophrenia.
Collapse
Affiliation(s)
- Adrianna P. Kępińska
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Conrad O. Iyegbe
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Anthony C. Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, United Kingdom
| | - Robert Yolken
- Stanley Laboratory of Developmental Neurovirology, Johns Hopkins Medical Center, Baltimore, MD, United States
| | - Robin M. Murray
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Thomas A. Pollak
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| |
Collapse
|
18
|
Nudel R, Wang Y, Appadurai V, Schork AJ, Buil A, Agerbo E, Bybjerg-Grauholm J, Børglum AD, Daly MJ, Mors O, Hougaard DM, Mortensen PB, Werge T, Nordentoft M, Thompson WK, Benros ME. A large-scale genomic investigation of susceptibility to infection and its association with mental disorders in the Danish population. Transl Psychiatry 2019; 9:283. [PMID: 31712607 PMCID: PMC6848113 DOI: 10.1038/s41398-019-0622-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/06/2019] [Accepted: 10/03/2019] [Indexed: 12/17/2022] Open
Abstract
Infections and mental disorders are two of the major global disease burdens. While correlations between mental disorders and infections have been reported, the possible genetic links between them have not been assessed in large-scale studies. Moreover, the genetic basis of susceptibility to infection is largely unknown, as large-scale genome-wide association studies of susceptibility to infection have been lacking. We utilized a large Danish population-based sample (N = 65,534) linked to nationwide population-based registers to investigate the genetic architecture of susceptibility to infection (heritability estimation, polygenic risk analysis, and a genome-wide association study (GWAS)) and examined its association with mental disorders (comorbidity analysis and genetic correlation). We found strong links between having at least one psychiatric diagnosis and the occurrence of infection (P = 2.16 × 10-208, OR = 1.72). The SNP heritability of susceptibility to infection ranged from ~2 to ~7% in samples of differing psychiatric diagnosis statuses (suggesting the environment as a major contributor to susceptibility), and polygenic risk scores moderately but significantly explained infection status in an independent sample. We observed a genetic correlation of 0.496 (P = 2.17 × 10-17) between a diagnosis of infection and a psychiatric diagnosis. While our GWAS did not identify genome-wide significant associations, we found 90 suggestive (P ≤ 10-5) associations for susceptibility to infection. Our findings suggest a genetic component in susceptibility to infection and indicate that the occurrence of infections in individuals with mental illness may be in part genetically driven.
Collapse
Affiliation(s)
- Ron Nudel
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Mental Health Services Copenhagen, Roskilde, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
| | - Yunpeng Wang
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- Norwegian Centre for Mental Disorders Research, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | - Vivek Appadurai
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Mental Health Services Copenhagen, Roskilde, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
| | - Andrew J Schork
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Mental Health Services Copenhagen, Roskilde, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
| | - Alfonso Buil
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Mental Health Services Copenhagen, Roskilde, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
| | - Esben Agerbo
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- National Center for Register-Based Research, Aarhus University, Aarhus, Denmark
- CIRRAU-Center for Integrated Register-based Research, Aarhus University, Aarhus, Denmark
| | - Jonas Bybjerg-Grauholm
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- Center for Neonatal Screening, Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Anders D Børglum
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- Department of Biomedicine, Aarhus University and Centre for Integrative Sequencing, iSEQ, Aarhus, Denmark
- Aarhus Genome Center, Aarhus, Denmark
| | - Mark J Daly
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Ole Mors
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- Psychosis Research Unit, Aarhus University Hospital, Risskov, Denmark
| | - David M Hougaard
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- Center for Neonatal Screening, Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Preben B Mortensen
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- National Center for Register-Based Research, Aarhus University, Aarhus, Denmark
| | - Thomas Werge
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Mental Health Services Copenhagen, Roskilde, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Merete Nordentoft
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Mental Health Centre Copenhagen, Copenhagen University Hospital, Copenhagen, Denmark
| | - Wesley K Thompson
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Mental Health Services Copenhagen, Roskilde, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark
- Department of Family Medicine and Public Health, Division of Biostatistics, University of California, San Diego, CA, USA
| | - Michael E Benros
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus V, Denmark.
- Mental Health Centre Copenhagen, Copenhagen University Hospital, Copenhagen, Denmark.
| |
Collapse
|
19
|
Torrey EF, Yolken RH. Schizophrenia as a pseudogenetic disease: A call for more gene-environmental studies. Psychiatry Res 2019; 278:146-150. [PMID: 31200193 DOI: 10.1016/j.psychres.2019.06.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 01/22/2023]
Abstract
In recent years schizophrenia has been assumed to be largely a genetic disease with heritability estimates, derived primarily from family and twin studies, of 80%-85%. However, the results of genetic research on schizophrenia have not yielded results consistent with that estimate of heritability. In particular, extensive genetic studies have not led to new methods for diagnosis and treatment. An examination of the twin studies on which heritability is based shows why such studies exaggerate the genetic component of schizophrenia. In addition, the effects of infectious agents such as Toxoplasma gondii and the composition of the microbiome can produce a clinical picture that would also appear to be largely genetic due to familial aggregation and a role for a partial genetic contribution to the immune system. It is concluded that the genetic component of schizophrenia may have been overestimated and an increased focus on gene-environmental interactions is likely to accelerate research progress on this disease.
Collapse
Affiliation(s)
- E Fuller Torrey
- Stanley Medical Research Institute, 301-571-2078, 10605 Concord St, Suite 206, Kensington, MD20895, USA.
| | - Robert H Yolken
- Stanley Laboratory of Developmental Neurovirology, Johns Hopkins Medical Center, Baltimore, MD, USA
| |
Collapse
|