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Elkrief L, Lin B, Marchi M, Afzali MH, Banaschewski T, Bokde ALW, Quinlan EB, Desrivières S, Flor H, Garavan H, Gowland P, Heinz A, Ittermann B, Martinot JL, Martinot MLP, Nees F, Orfanos DP, Paus T, Poustka L, Hohmann S, Fröhner JH, Smolka MN, Walter H, Whelan R, Schumann G, Luykx J, Boks MP, Conrod PJ. Independent contribution of polygenic risk for schizophrenia and cannabis use in predicting psychotic-like experiences in young adulthood: testing gene × environment moderation and mediation. Psychol Med 2023; 53:1759-1769. [PMID: 37310336 PMCID: PMC10106286 DOI: 10.1017/s0033291721003378] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND It has not yet been determined if the commonly reported cannabis-psychosis association is limited to individuals with pre-existing genetic risk for psychotic disorders. METHODS We examined whether the relationship between polygenic risk score for schizophrenia (PRS-Sz) and psychotic-like experiences (PLEs), as measured by the Community Assessment of Psychic Experiences-42 (CAPE-42) questionnaire, is mediated or moderated by lifetime cannabis use at 16 years of age in 1740 of the individuals of the European IMAGEN cohort. Secondary analysis examined the relationships between lifetime cannabis use, PRS-Sz and the various sub-scales of the CAPE-42. Sensitivity analyses including covariates, including a PRS for cannabis use, were conducted and results were replicated using data from 1223 individuals in the Dutch Utrecht cannabis cohort. RESULTS PRS-Sz significantly predicted cannabis use (p = 0.027) and PLE (p = 0.004) in the IMAGEN cohort. In the full model, considering PRS-Sz and covariates, cannabis use was also significantly associated with PLE in IMAGEN (p = 0.007). Results remained consistent in the Utrecht cohort and through sensitivity analyses. Nevertheless, there was no evidence of a mediation or moderation effects. CONCLUSIONS These results suggest that cannabis use remains a risk factor for PLEs, over and above genetic vulnerability for schizophrenia. This research does not support the notion that the cannabis-psychosis link is limited to individuals who are genetically predisposed to psychosis and suggests a need for research focusing on cannabis-related processes in psychosis that cannot be explained by genetic vulnerability.
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Affiliation(s)
- Laurent Elkrief
- Sainte-Justine Hospital Research Center, Montréal, Québec, Canada
- Département de psychiatrie et d'addictologie, Université de Montréal, Montréal, QC, Canada
| | - Bochao Lin
- Department of Translational Neuroscience, Brain Center University Medical Center, Utrecht University, Utrecht, the Netherlands
| | - Mattia Marchi
- Department Psychiatry, Brain Center University Medical Center Utrecht, Utrecht, the Netherlands
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Giuseppe Campi, 287–41125 Modena, Italy
| | - Mohammad H Afzali
- Sainte-Justine Hospital Research Center, Montréal, Québec, Canada
- Département de psychiatrie et d'addictologie, Université de Montréal, Montréal, QC, Canada
| | - Tobias Banaschewski
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany
| | - Arun L. W. Bokde
- Discipline of Psychiatry, School of Medicine and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Erin Burke Quinlan
- Centre for Population Neuroscience and Precision Medicine (PONS), Institute of Psychiatry, Psychology & Neuroscience, SGDP Centre, King's College London, United Kingdom
| | - Sylvane Desrivières
- Centre for Population Neuroscience and Precision Medicine (PONS), Institute of Psychiatry, Psychology & Neuroscience, SGDP Centre, King's College London, United Kingdom
| | - Herta Flor
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, Mannheim, Germany
- Department of Psychology, School of Social Sciences, University of Mannheim, 68131 Mannheim, Germany
| | - Hugh Garavan
- Departments of Psychiatry and Psychology, University of Vermont, 05405 Burlington, Vermont, USA
| | - Penny Gowland
- Sir Peter Mansfield Imaging Centre School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Andreas Heinz
- Charité – Universitätsmedizin Berlin, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charitéplatz 1, Berlin, Germany
| | - Bernd Ittermann
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2 - 12, Berlin, Germany
| | - Jean-Luc Martinot
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1000 “Neuroimaging & Psychiatry”, University Paris Saclay, University Paris Descartes - Sorbonne Paris Cité; and Maison de Solenn, Paris, France
| | - Marie-Laure Paillère Martinot
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1000 “Neuroimaging & Psychiatry”, University Paris Sud, University Paris Descartes; and AP-HP.Sorbonne Université, Department of Child and Adolescent Psychiatry, Pitié-Salpêtrière Hospital, Paris, France
| | - Frauke Nees
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, Mannheim, Germany
| | | | - Tomáš Paus
- Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
| | - Luise Poustka
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Medical Centre Göttingen, von-Siebold-Str. 5, 37075, Göttingen, Germany
| | - Sarah Hohmann
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany
| | - Juliane H. Fröhner
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Michael N. Smolka
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Henrik Walter
- Charité – Universitätsmedizin Berlin, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charitéplatz 1, Berlin, Germany
| | - Robert Whelan
- School of Psychology and Global Brain Health Institute, Trinity College Dublin, Ireland
| | - Gunter Schumann
- Centre for Population Neuroscience and Precision Medicine (PONS), Institute of Psychiatry, Psychology & Neuroscience, SGDP Centre, King's College London, United Kingdom
- School of Psychology and Global Brain Health Institute, Trinity College Dublin, Ireland
- PONS Research Group, Dept of Psychiatry and Psychotherapy, Campus Charite Mitte, Humboldt University, Berlin and Leibniz Institute for Neurobiology, Magdeburg, Germany, and Institute for Science and Technology of Brain-inspired Intelligence (ISTBI), Fudan University, Shanghai, P.R. China
| | - Jurjen Luykx
- Department Psychiatry, Brain Center University Medical Center Utrecht, Utrecht, the Netherlands
| | - Marco P. Boks
- Department Psychiatry, Brain Center University Medical Center Utrecht, Utrecht, the Netherlands
| | - Patricia J. Conrod
- Sainte-Justine Hospital Research Center, Montréal, Québec, Canada
- Département de psychiatrie et d'addictologie, Université de Montréal, Montréal, QC, Canada
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2
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Marchi M, Elkrief L, Alkema A, van Gastel W, Schubart CD, van Eijk KR, Luykx JJ, Branje S, Mastrotheodoros S, Galeazzi GM, van Os J, Cecil CA, Conrod PJ, Boks MP. Childhood maltreatment mediates the effect of the genetic background on psychosis risk in young adults. Transl Psychiatry 2022; 12:219. [PMID: 35650188 PMCID: PMC9160238 DOI: 10.1038/s41398-022-01975-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/29/2022] [Accepted: 05/10/2022] [Indexed: 11/09/2022] Open
Abstract
Childhood maltreatment (CM) and genetic vulnerability are both risk factors for psychosis, but the relations between them are not fully understood. Guided by the recent identification of genetic risk to CM, this study investigates the hypothesis that genetic risk to schizophrenia also increases the risk of CM and thus impacts psychosis risk. The relationship between schizophrenia polygenetic risk, CM, and psychotic-like experiences (PLE) was investigated in participants from the Utrecht Cannabis Cohort (N = 1262) and replicated in the independent IMAGEN cohort (N = 1740). Schizophrenia polygenic risk score (SZ-PRS) were calculated from the most recent GWAS. The relationship between CM, PRS, and PLE was first investigated using multivariate linear regression. Next, mediation of CM in the pathway linking SZ-PRS and PLE was examined by structural equation modeling, while adjusting for a set of potential mediators including cannabis use, smoking, and neuroticism. In agreement with previous studies, PLE were strongly associated with SZ-PRS (B = 0.190, p = 0.009) and CM (B = 0.575, p < 0.001). Novel was that CM was also significantly associated with SZ-PRS (B = 0.171, p = 0.001), and substantially mediated the effects of SZ-PRS on PLE (proportion mediated = 29.9%, p = 0.001). In the replication cohort, the analyses yielded similar results, confirming equally strong mediation by CM (proportion mediated = 34.7%, p = 0.009). Our results suggest that CM acts as a mediator in the causal pathway linking SZ-PRS and psychosis risk. These findings open new perspectives on the relations between genetic and environmental risks and warrant further studies into potential interventions to reduce psychosis risk in vulnerable people.
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Affiliation(s)
- Mattia Marchi
- grid.7548.e0000000121697570Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Giuseppe Campi, 287 – 41125 Modena, Italy ,grid.5477.10000000120346234Department of Psychiatry, Brain Center University Medical Center Utrecht, University Utrecht, Utrecht, The Netherlands
| | - Laurent Elkrief
- grid.14848.310000 0001 2292 3357Department of Psychiatry, Université de Montréal, CHU Sainte-Justine Hospital, Montréal, QC Canada ,grid.411418.90000 0001 2173 6322Center Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC Canada
| | - Anne Alkema
- grid.5477.10000000120346234Department of Psychiatry, Brain Center University Medical Center Utrecht, University Utrecht, Utrecht, The Netherlands
| | - Willemijn van Gastel
- grid.5477.10000000120346234Department of Psychology, Utrecht University, Utrecht, The Netherlands
| | - Chris D. Schubart
- grid.413202.60000 0004 0626 2490Department of Psychiatry, Tergooi Hospital, Blaricum, The Netherlands
| | - Kristel R. van Eijk
- grid.5477.10000000120346234Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Jurjen J. Luykx
- grid.5477.10000000120346234Department of Psychiatry, Brain Center University Medical Center Utrecht, University Utrecht, Utrecht, The Netherlands
| | - Susan Branje
- grid.5477.10000000120346234Department of Youth and Family, Faculty of Social and Behavioral Sciences, Utrecht University, Utrecht, The Netherlands
| | - Stefanos Mastrotheodoros
- grid.5477.10000000120346234Department of Youth and Family, Faculty of Social and Behavioral Sciences, Utrecht University, Utrecht, The Netherlands ,grid.8127.c0000 0004 0576 3437Department of Psychology, University of Crete, Rethymno, Greece
| | - Gian M. Galeazzi
- grid.7548.e0000000121697570Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Giuseppe Campi, 287 – 41125 Modena, Italy ,Department of Mental Health and Addiction Services, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Jim van Os
- grid.5477.10000000120346234Department of Psychiatry, Brain Center University Medical Center Utrecht, University Utrecht, Utrecht, The Netherlands
| | - Charlotte A. Cecil
- grid.5645.2000000040459992XDepartment of Child and Adolescent Psychiatry, Erasmus Medical Center, Sophia Children’s Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands ,grid.5645.2000000040459992XDepartment of Epidemiology, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Patricia J. Conrod
- grid.14848.310000 0001 2292 3357Department of Psychiatry, Université de Montréal, CHU Sainte-Justine Hospital, Montréal, QC Canada ,grid.411418.90000 0001 2173 6322Center Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC Canada
| | - Marco P. Boks
- grid.5477.10000000120346234Department of Psychiatry, Brain Center University Medical Center Utrecht, University Utrecht, Utrecht, The Netherlands
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Differential Relations of Parental Behavior to Children's Early Executive Function as a Function of Child Genotype: A Systematic Review. Clin Child Fam Psychol Rev 2022; 25:435-470. [PMID: 35195834 DOI: 10.1007/s10567-022-00387-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2022] [Indexed: 11/03/2022]
Abstract
Child genotype is an important biologically based indicator of sensitivity to the effects of parental behavior on children's executive function (EF) in early childhood, birth to age 5. While evidence for gene × parental behavior interactions on children's early EF is growing, researchers have called the quality of evidence provided by gene × environment interaction studies into question. For this reason, this review comprehensively examined the literature and evaluated the evidence for gene × parental behavior interactions on children's early EF abilities. Psychology and psychiatry databases were searched for published peer-reviewed studies. A total of 18 studies met inclusion criteria. Twenty-nine of 89 (33%) examined interactions were significant. However, a p-curve analysis did not find the significant interactions to be of evidential value. A high rate of false positives, due to the continued use of candidate gene and haplotype measures of child genotype and small sample sizes, likely contributed to the high rate of significant interactions and low evidential value. The use of contemporary molecular genetic measures and larger sample sizes are necessary to advance our understanding of child genotype as a moderator of parental effects on children's EF during early childhood and the biopsychosocial mechanisms underlying children's EF development during this critical period. Without these changes, future research is likely to be stymied by the same limitations as current research.
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Boks MP, He Y, Schubart CD, Gastel WV, Elkrief L, Huguet G, Eijk KV, Vinkers CH, Kahn RS, Paus T, Conrod P, Hol EM, de Witte LD. Cannabinoids and psychotic symptoms: A potential role for a genetic variant in the P2X purinoceptor 7 (P2RX7) gene. Brain Behav Immun 2020; 88:573-581. [PMID: 32330591 DOI: 10.1016/j.bbi.2020.04.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 04/07/2020] [Accepted: 04/20/2020] [Indexed: 12/17/2022] Open
Abstract
To investigate the biological mechanisms underlying the higher risk for psychosis in those that use cannabis, we conducted a genome-wide environment-interaction study (GWEIS). In a sample of individuals without a psychiatric disorder (N = 1262), we analyzed the interactions between regular cannabis use and genotype with psychotic-like experiences (PLE) as outcome. PLE were measured using the Community Assessment of Psychic Experiences (CAPE). The sample was enriched for those at the extremes of both cannabis use and PLE to increase power. A single nucleotide polymorphism in the P2RX7 gene (rs7958311) was associated with risk for a high level of psychotic experiences in regular cannabis users (p = 1.10 x10-7) and in those with high levels of lifetime cannabis use (p = 4.5 × 10-6). This interaction was replicated in individuals with high levels of lifetime cannabis use in the IMAGEN cohort (N = 1217, p = 0.020). Functional relevance of P2RX7 in cannabis users was suggested by in vitro experiments on activated monocytes. Exposure of these cells to tetrahydrocannabinol (THC) or cannabidiol (CBD) reduced the immunological response of the P2X7 receptor, which was dependent on the identified genetic variant. P2RX7 variants have been implicated in psychiatric disorders before and the P2X7 receptor is involved in pathways relevant to psychosis, such as neurotransmission, synaptic plasticity and immune regulation. We conclude that P2RX7 plays a role in vulnerability to develop psychotic symptoms when using cannabis and point to a new pathway that can potentially be targeted by newly developed P2X7 antagonists.
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Affiliation(s)
- Marco P Boks
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht University, The Netherlands
| | - Yujie He
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht University, The Netherlands
| | - Chris D Schubart
- Department of Psychiatry, Tergooi Hospital, Blaricum, The Netherlands
| | | | - Laurent Elkrief
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Guillaume Huguet
- Department of Pediatrics, Université de Montréal, Montreal, Quebec, Canada; Center Hospitalier Universitaire Sainte-Justine Research Center, Montreal, Quebec, Canada
| | - Kristel van Eijk
- Department of Neurology and Neurosurgery, UMC Utrecht Brain Center, Utrecht University, The Netherlands
| | - Christiaan H Vinkers
- Department of Psychiatry, Amsterdam UMC (location VUmc), Amsterdam, The Netherlands; Department of Anatomy and Neurosciences, Amsterdam UMC (location VUmc), Amsterdam, The Netherlands
| | - René S Kahn
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht University, The Netherlands; Department of psychiatry, Icahn School of Medicine at Mount Sinai, New York City, USA
| | - Tomás Paus
- Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital and Departments of Psychology and Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Patricia Conrod
- Center Hospitalier Universitaire Sainte-Justine Research Center, Montreal, Quebec, Canada; Department of Psychiatry, University of Montreal, Montréal, QC, Canada
| | - Elly M Hol
- Department of Translational Neuroscience, UMC Utrecht Brain Center, Utrecht University, The Netherlands; Neuroimmunology Research Group, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, Netherlands
| | - Lot D de Witte
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht University, The Netherlands; Department of psychiatry, Icahn School of Medicine at Mount Sinai, New York City, USA.
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5
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Osazuwa-Peters OL, Schwander K, Waken RJ, de Las Fuentes L, Kilpeläinen TO, Loos RJF, Racette SB, Sung YJ, Rao DC. The Promise of Selecting Individuals from the Extremes of Exposure in the Analysis of Gene-Physical Activity Interactions. Hum Hered 2019; 83:315-332. [PMID: 31167214 DOI: 10.1159/000499711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 03/19/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Dichotomization using the lower quartile as cutoff is commonly used for harmonizing heterogeneous physical activity (PA) measures across studies. However, this may create misclassification and hinder discovery of new loci. OBJECTIVES This study aimed to evaluate the performance of selecting individuals from the extremes of the exposure (SIEE) as an alternative approach to reduce such misclassification. METHOD For systolic and diastolic blood pressure in the Framingham Heart Study, we performed a genome-wide association study with gene-PA interaction analysis using three PA variables derived by SIEE and two other dichotomization approaches. We compared number of loci detected and overlap with loci found using a quantitative PA variable. In addition, we performed simulation studies to assess bias, false discovery rates (FDR), and power under synergistic/antagonistic genetic effects in exposure groups and in the presence/absence of measurement error. RESULTS In the empirical analysis, SIEE's performance was neither the best nor the worst. In most simulation scenarios, SIEE was consistently outperformed in terms of FDR and power. Particularly, in a scenario characterized by antagonistic effects and measurement error, SIEE had the least bias and highest power. CONCLUSION SIEE's promise appears limited to detecting loci with antagonistic effects. Further studies are needed to evaluate SIEE's full advantage.
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Affiliation(s)
| | - Karen Schwander
- Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - R J Waken
- Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Lisa de Las Fuentes
- Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri, USA.,Cardiovascular Division, Department of Medicine, Washington University, St. Louis, Missouri, USA
| | - Tuomas O Kilpeläinen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Environmental Medicine and Public Health, The Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Ruth J F Loos
- Icahn School of Medicine at Mount Sinai, The Charles Bronfman Institute for Personalized Medicine, New York, New York, USA.,Icahn School of Medicine at Mount Sinai, The Mindich Child Health and Development Institute, New York, New York, USA
| | - Susan B Racette
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Yun Ju Sung
- Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - D C Rao
- Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri, USA
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6
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He Y, de Witte LD, Schubart CD, Van Gastel WA, Koeleman BPC, de Jong S, Ophoff RA, Hol EM, Boks MP. Liprin alfa 2 gene expression is increased by cannabis use and associated with neuropsychological function. Eur Neuropsychopharmacol 2019; 29:643-652. [PMID: 30879928 DOI: 10.1016/j.euroneuro.2019.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 01/13/2019] [Accepted: 03/02/2019] [Indexed: 11/18/2022]
Abstract
The relation of heavy cannabis use with decreased neuropsychological function has frequently been described but the underlying biological mechanisms are still largely unknown. This study investigates the relation of cannabis use with genome wide gene expression and subsequently examines the relations with neuropsychological function. Genome-wide gene expression in whole blood was compared between heavy cannabis users (N = 90) and cannabis naïve participants (N = 100) that were matched for psychotic like experiences. The results were validated using quantitative real-time PCR. Psychotic like experiences were assessed using the Comprehensive Assessment of Psychotic Experiences (CAPE). Neuropsychological function was estimated using four subtasks of the Wechsler Adult Intelligence Scale (WAIS). Subsequent in vitro studies in monocytes and a neuroblastoma cell line investigated expression changes in response to two major psychotropic components of cannabis; tetrahydrocannabinol (THC) and cannabidiol (CBD). mRNA expression of Protein Tyrosine Phosphatase Receptor Type F Polypeptide-Interacting-Protein Alpha-2 (PPFIA2) was significantly higher in cannabis users (LogFold Change 0.17) and confirmed by qPCR analysis. PPFIA2 expression level was negatively correlated with estimated intelligence (B=-22.9, p = 0.002) also in the 100 non-users (B=-28.5, p = 0.037). In vitro exposure of monocytes to CBD led to significant increase in PPFIA2 expression. However, exposure of monocytes to THC and neuroblastoma cells to THC or CBD did not change PPFIA2 expression. Change in PPFIA2 gene expression in response to cannabinoids is a putative mechanism by which cannabis could influence neuropsychological functions. The findings warrant further exploration of the role of PPFIA2 in cannabis induced changes of neuropsychological function, particularly in relation to CBD.
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Affiliation(s)
- Yujie He
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, The Netherlands; Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, The Netherlands
| | - Lot D de Witte
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, The Netherlands; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Chris D Schubart
- Ter Gooi Hospital, Department of Psychiatry, Blaricum, The Netherlands
| | | | - Bobby P C Koeleman
- Department of Medical Genetics, University Medical Centre Utrecht, Utrecht University, The Netherlands
| | - Simone de Jong
- MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK
| | - Roel A Ophoff
- UCLA Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, Los Angeles, CA, USA
| | - Elly M Hol
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, The Netherlands; Neuroimmunology, Netherlands Institute for Neuroscience, An institute of the royal academy of arts and sciences, Amsterdam, The Netherlands
| | - Marco P Boks
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, The Netherlands.
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Longitudinal changes in glucocorticoid receptor exon 1 F methylation and psychopathology after military deployment. Transl Psychiatry 2017; 7:e1181. [PMID: 28742078 PMCID: PMC5538126 DOI: 10.1038/tp.2017.150] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 05/26/2017] [Accepted: 06/07/2017] [Indexed: 11/13/2022] Open
Abstract
Several cross-sectional studies have demonstrated the relevance of DNA methylation of the glucocorticoid receptor exon 1F region (GR-1F) for trauma-related psychopathology. We conducted a longitudinal study to examine GR-1F methylation changes over time in relation to trauma exposure and the development of post-deployment psychopathology. GR-1F methylation (52 loci) was quantified using pyrosequencing in whole blood of 92 military men 1 month before and 6 months after a 4-month deployment period to Afghanistan. GR-1F methylation overall (mean methylation and the number of methylated loci) and functional methylation (methylation at loci associated with GR exon 1F expression) measures were examined. We first investigated the effect of exposure to potentially traumatic events during deployment on these measures. Subsequently, changes in GR-1F methylation were related to changes in mental health problems (total Symptom Checklist-90 score) and posttraumatic stress disorder (PTSD) symptoms (Self-Report Inventory for PTSD). Trauma exposure during deployment was associated with an increase in all methylation measures, but development of mental health problems 6 months after deployment was only significantly associated with an increased functional methylation. Emergence of post-deployment PTSD symptoms was not related to increased functional methylation over time. Pre-deployment methylation levels did not predict post-deployment psychopathology. To our knowledge, this is the first study to prospectively demonstrate trauma-related increases in GR-1F methylation, and it shows that only increases at specific functionally relevant sites predispose for post-deployment psychopathology.
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Sun Z, Mukherjee B, Estes JP, Vokonas PS, Park SK. Exposure enriched outcome dependent designs for longitudinal studies of gene-environment interaction. Stat Med 2017; 36:2947-2960. [PMID: 28497531 DOI: 10.1002/sim.7332] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 03/08/2017] [Accepted: 04/20/2017] [Indexed: 12/15/2022]
Abstract
Joint effects of genetic and environmental factors have been increasingly recognized in the development of many complex human diseases. Despite the popularity of case-control and case-only designs, longitudinal cohort studies that can capture time-varying outcome and exposure information have long been recommended for gene-environment (G × E) interactions. To date, literature on sampling designs for longitudinal studies of G × E interaction is quite limited. We therefore consider designs that can prioritize a subsample of the existing cohort for retrospective genotyping on the basis of currently available outcome, exposure, and covariate data. In this work, we propose stratified sampling based on summaries of individual exposures and outcome trajectories and develop a full conditional likelihood approach for estimation that adjusts for the biased sample. We compare the performance of our proposed design and analysis with combinations of different sampling designs and estimation approaches via simulation. We observe that the full conditional likelihood provides improved estimates for the G × E interaction and joint exposure effects over uncorrected complete-case analysis, and the exposure enriched outcome trajectory dependent design outperforms other designs in terms of estimation efficiency and power for detection of the G × E interaction. We also illustrate our design and analysis using data from the Normative Aging Study, an ongoing longitudinal cohort study initiated by the Veterans Administration in 1963. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Zhichao Sun
- Department of Biostatistics, University of Michigan, Ann Arbor, 48109, MI, U.S.A
| | - Bhramar Mukherjee
- Department of Biostatistics, University of Michigan, Ann Arbor, 48109, MI, U.S.A.,Department of Epidemiology, University of Michigan, Ann Arbor, 48109, MI, U.S.A
| | - Jason P Estes
- Department of Biostatistics, University of Michigan, Ann Arbor, 48109, MI, U.S.A
| | - Pantel S Vokonas
- Veterans Affairs Normative Aging Study, VA Boston Healthcare System, Department of Medicine, Boston University School of Medicine, Boston, 02118, MA, U.S.A
| | - Sung Kyun Park
- Department of Epidemiology, University of Michigan, Ann Arbor, 48109, MI, U.S.A.,Department of Environmental Health Sciences, University of Michigan, Ann Arbor, 48109, MI, U.S.A
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9
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Assessing gene-environment interaction effects of FTO, MC4R and lifestyle factors on obesity using an extreme phenotype sampling design: Results from the HUNT study. PLoS One 2017; 12:e0175071. [PMID: 28384342 PMCID: PMC5383228 DOI: 10.1371/journal.pone.0175071] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/19/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Our aim was to assess the influence of age, gender and lifestyle factors on the effect of the obesity-promoting alleles of FTO and MCR4. METHODS The HUNT study comprises health information on the population of Nord-Trøndelag county, Norway. Extreme phenotype participants (gender-wise lower and upper quartiles of waist-hip-ratio and BMI ≥ 35 kg/m2) in the third survey, HUNT3 (2006-08), were genotyped for the single-nucleotide polymorphisms rs9939609 (FTO) and rs17782313 (MC4R); 25686 participants were successfully genotyped. Extreme sampling was chosen to increase power to detect genetic and gene-environment effects on waist-hip-ratio and BMI. Statistical inference was based on linear regression models and a missing-covariate likelihood approach for the extreme phenotype sampling design. Environmental factors were physical activity, diet (artificially sweetened beverages) and smoking. Longitudinal analysis was performed using material from HUNT2 (1995-97). RESULTS Cross-sectional and longitudinal genetic effects indicated stronger genetic associations with obesity in young than in old, as well as differences between women and men. We observed larger genetic effects among physically inactive compared to active individuals. This interaction was age-dependent and seen mainly in 20-40 year olds. We observed a greater FTO effect among men with a regular intake of artificially sweetened beverages, compared to non-drinkers. Interaction analysis of smoking was mainly inconclusive. CONCLUSIONS In a large all-adult and area-based population survey the effects of obesity-promoting minor-alleles of FTO and MCR4, and interactions with life style factors are age- and gender-related. These findings appear relevant when designing individualized treatment for and prophylaxis against obesity.
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Boks MP, Rutten BPF, Geuze E, Houtepen LC, Vermetten E, Kaminsky Z, Vinkers CH. SKA2 Methylation is Involved in Cortisol Stress Reactivity and Predicts the Development of Post-Traumatic Stress Disorder (PTSD) After Military Deployment. Neuropsychopharmacology 2016; 41:1350-6. [PMID: 26361058 PMCID: PMC4793119 DOI: 10.1038/npp.2015.286] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/18/2015] [Accepted: 08/28/2015] [Indexed: 02/04/2023]
Abstract
Genomic variation in the SKA2 gene has recently been identified as a promising suicide biomarker. In light of its role in glucocorticoid receptor transactivation, we investigated whether SKA2 DNA methylation influences cortisol stress reactivity and is involved in the development of post-traumatic stress disorder (PTSD). Increased SKA2 methylation was significantly associated with lower cortisol stress reactivity in 85 healthy individuals exposed to the Trier Social Stress Test (B=-173.40, t=-2.324, p-value=0.023). Next, we observed that longitudinal decreases in SKA2 methylation after deployment were associated with the emergence of post-deployment PTSD symptoms in a Dutch military cohort (N=93; B=-0.054, t=-3.706, p-value=3.66 × 10(-4)). In contrast, exposure to traumatic stress during deployment by itself resulted in longitudinal increases in SKA2 methylation (B=0.037, t=4.173, p-value=6.98 × 10(-5)). Using pre-deployment SKA2 methylation levels and childhood trauma exposure, we found that the previously published suicide prediction rule significantly predicted post-deployment PTSD symptoms (AUC=0.66, 95% CI: 0.53-0.79) with an optimal sensitivity of 0.81 and specificity of 0.91. Permutation analysis using random methylation loci supported these findings. Together, these data establish the importance of SKA2 for cortisol stress responsivity and the development of PTSD and provide further evidence that SKA2 is a promising biomarker for stress-related disorders including PTSD.
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Affiliation(s)
- Marco P Boks
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Centre Utrecht, Utrecht, The Netherlands,Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Centre Utrecht, HP. A.01.489, PO Box 85500, Utrecht, 3508 GA, The Netherlands, Tel: +31 88 7556370, Fax: +31 88 7555509, E-mail:
| | - Bart P F Rutten
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Elbert Geuze
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Centre Utrecht, Utrecht, The Netherlands,Research Centre Military Mental Healthcare, Ministry of Defence, The Hague, The Netherlands
| | - Lotte C Houtepen
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Eric Vermetten
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Centre Utrecht, Utrecht, The Netherlands,Research Centre Military Mental Healthcare, Ministry of Defence, The Hague, The Netherlands,Department of Psychiatry, Leiden University Medical Center, Utrecht, The Netherlands,Arq Psychotrauma Expert Group, Diemen, The Netherlands
| | - Zachary Kaminsky
- Department of Psychiatry and Behavioral Sciences, The Mood Disorders Center, Johns Hopkins School of Medicine, Baltimore, MD, USA,Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Christiaan H Vinkers
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Centre Utrecht, Utrecht, The Netherlands
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11
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Longitudinal changes of telomere length and epigenetic age related to traumatic stress and post-traumatic stress disorder. Psychoneuroendocrinology 2015; 51:506-12. [PMID: 25129579 DOI: 10.1016/j.psyneuen.2014.07.011] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 07/02/2014] [Accepted: 07/05/2014] [Indexed: 11/20/2022]
Abstract
Several studies have reported an association between traumatic stress and telomere length suggesting that traumatic stress has an impact on ageing at the cellular level. A newly derived tool provides an additional means to investigate cellular ageing by estimating epigenetic age based on DNA methylation profiles. We therefore hypothesise that in a longitudinal study of traumatic stress both indicators of cellular ageing will show increased ageing. We expect that particularly in individuals that developed symptoms of post-traumatic stress disorder (PTSD) increases in these ageing parameters would stand out. From an existing longitudinal cohort study, ninety-six male soldiers were selected based on trauma exposure and the presence of symptoms of PTSD. All military personnel were deployed in a combat zone in Afghanistan and assessed before and 6 months after deployment. The Self-Rating Inventory for PTSD was used to measure the presence of PTSD symptoms, while exposure to combat trauma during deployment was measured with a 19-item deployment experiences checklist. These groups did not differ for age, gender, alcohol consumption, cigarette smoking, military rank, length, weight, or medication use. In DNA from whole blood telomere length was measured and DNA methylation levels were assessed using the Illumina 450K DNA methylation arrays. Epigenetic ageing was estimated using the DNAm age estimator procedure. The association of trauma with telomere length was in the expected direction but not significant (B=-10.2, p=0.52). However, contrary to our expectations, development of PTSD symptoms was associated with the reverse process, telomere lengthening (B=1.91, p=0.018). In concordance, trauma significantly accelerated epigenetic ageing (B=1.97, p=0.032) and similar to the findings in telomeres, development of PTSD symptoms was inversely associated with epigenetic ageing (B=-0.10, p=0.044). Blood cell count, medication and premorbid early life trauma exposure did not confound the results. Overall, in this longitudinal study of military personnel deployed to Afghanistan we show an acceleration of ageing by trauma. However, development of PTSD symptoms was associated with telomere lengthening and reversed epigenetic ageing. These findings warrant further study of a perhaps dysfunctional compensatory cellular ageing reversal in PTSD.
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12
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Molecular genetic gene-environment studies using candidate genes in schizophrenia: a systematic review. Schizophr Res 2013; 150:356-65. [PMID: 24094883 DOI: 10.1016/j.schres.2013.09.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/03/2013] [Accepted: 09/14/2013] [Indexed: 12/25/2022]
Abstract
The relatively high heritability of schizophrenia suggests that genetic factors play an important role in the etiology of the disorder. On the other hand, a number of environmental factors significantly influence its incidence. As few direct genetic effects have been demonstrated, and there is considerable inter-individual heterogeneity in the response to the known environmental factors, interactions between genetic and environmental factors may be important in determining whether an individual develops the disorder. To date, a considerable number of studies of gene-environment interactions (G×E) in schizophrenia have employed a hypothesis-based molecular genetic approach using candidate genes, which have led to a range of different findings. This systematic review aims to summarize the results from molecular genetic candidate studies and to review challenges and opportunities of this approach in psychosis research. Finally, we discuss the potential of future prospects, such as new studies that combine hypothesis-based molecular genetic candidate approaches with agnostic genome-wide association studies in determining schizophrenia risk.
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13
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Vinkers CH, Van Gastel WA, Schubart CD, Van Eijk KR, Luykx JJ, Van Winkel R, Joëls M, Ophoff RA, Boks MPM, Bruggeman R, Cahn W, de Haan L, Kahn RS, Meijer CJ, Myin-Germeys I, van Os J, Wiersma D. The effect of childhood maltreatment and cannabis use on adult psychotic symptoms is modified by the COMT Val¹⁵⁸Met polymorphism. Schizophr Res 2013; 150:303-11. [PMID: 23954148 DOI: 10.1016/j.schres.2013.07.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 06/23/2013] [Accepted: 07/08/2013] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cannabis use and childhood maltreatment are independent risk factors for the development of psychotic symptoms. These factors have been found to interact in some but not all studies. One of the reasons may be that childhood maltreatment and cannabis primarily induce psychotic symptoms in genetically susceptible individuals. In this context, an extensively studied psychosis vulnerability gene is catechol-methyl-transferase (COMT). Therefore, we aimed to examine whether the COMT Val(158)Met polymorphism (rs4680) moderates the interaction between childhood maltreatment and cannabis use on psychotic symptoms in the general population. METHOD The discovery sample consisted of 918 individuals from a cross-sectional study. For replication we used an independent sample of 339 individuals from the general population. RESULTS A significant three-way interaction was found between childhood maltreatment, cannabis use, and the COMT genotype (rs4680) in the discovery sample (P=0.006). Val-homozygous individuals displayed increased psychotic experiences after exposure to both cannabis use and childhood maltreatment compared to Met-heterozygous and Met-homozygous individuals. Supportive evidence was found in the replication sample with similar effect and direction even though the results did not reach statistical significance (P=0.25). CONCLUSIONS These findings suggest that a functional polymorphism in the COMT gene may moderate the interaction between childhood maltreatment and cannabis use on psychotic experiences in the general population. In conclusion, the COMT Val(158)Met polymorphism may constitute a genetic risk factor for psychotic symptoms in the context of combined exposure to childhood maltreatment and cannabis use.
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Affiliation(s)
- Christiaan H Vinkers
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht (UMCU), Utrecht, The Netherlands; Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences and Rudolf Magnus Institute of Neuroscience, Utrecht University, Utrecht, The Netherlands.
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14
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Ahmad S, Varga TV, Franks PW. Gene × environment interactions in obesity: the state of the evidence. Hum Hered 2013; 75:106-15. [PMID: 24081226 DOI: 10.1159/000351070] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Obesity is a pervasive and highly prevalent disease that poses substantial health risks to those it affects. The rapid emergence of obesity as a global epidemic and the patterns and distributions of the condition within and between populations suggest that interactions between inherited biological factors (e.g. genes) and relevant environmental factors (e.g. diet and physical activity) may underlie the current obesity epidemic. METHODS We discuss the rationale for the assertion that gene × lifestyle interactions cause obesity, systematically appraise relevant literature, and consider knowledge gaps future studies might seek to bridge. RESULTS We identified >200 relevant studies, of which most are relatively small scale and few provide replication data. CONCLUSION Although studies on gene × lifestyle interactions in obesity point toward the presence of such interactions, improved data standardization, appropriate pooling of data and resources, innovative study designs, and the application of powerful statistical methods will be required if translatable examples of gene × lifestyle interactions in obesity are to be identified. Future studies, of which most will be observational, should ideally be accompanied by appropriate replication data and, where possible, by analogous findings from experimental settings where clinically relevant traits (e.g. weight regain and weight cycling) are outcomes.
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Affiliation(s)
- Shafqat Ahmad
- Genetic and Molecular Epidemiology Unit, Department of Clinical Science, Lund University, Malmö, Sweden
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15
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Interaction between the MTHFR C677T polymorphism and traumatic childhood events predicts depression. Transl Psychiatry 2013; 3:e288. [PMID: 23900311 PMCID: PMC3731792 DOI: 10.1038/tp.2013.60] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 05/30/2013] [Accepted: 06/04/2013] [Indexed: 12/20/2022] Open
Abstract
Childhood trauma is associated with the onset and recurrence of major depressive disorder (MDD). The thermolabile T variant of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) is associated with a limited (oxidative) stress defense. Therefore, C677T MTHFR could be a potential predictor for depressive symptomatology and MDD recurrence in the context of traumatic stress during early life. We investigated the interaction between the C677T MTHFR variant and exposure to traumatic childhood events (TCEs) on MDD recurrence during a 5.5-year follow-up in a discovery sample of 124 patients with recurrent MDD and, in an independent replication sample, on depressive symptomatology in 665 healthy individuals from the general population. In the discovery sample, Cox regression analysis revealed a significant interaction between MTHFR genotype and TCEs on MDD recurrence (P=0.017). Over the 5.5-year follow-up period, median time to recurrence was 191 days for T-allele carrying patients who experienced TCEs (T+ and TCE+); 461 days for T- and TCE+ patients; 773 days for T+ and TCE- patients and 866 days for T- and TCE- patients. In the replication sample, a significant interaction was present between the MTHFR genotype and TCEs on depressive symptomatology (P=0.002). Our results show that the effects of TCEs on the prospectively assessed recurrence of MDD and self-reported depressive symptoms in the general population depend on the MTHFR genotype. In conclusion, T-allele carriers may be at an increased risk for depressive symptoms or MDD recurrence after exposure to childhood trauma.
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16
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Affiliation(s)
- Marco P Boks
- Rudolf Magnus Institute of Neuroscience, University Medical Centre, Utrecht, The Netherlands.
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17
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Abstract
The global epidemic of type 2 diabetes mellitus (T2D) is one of the most challenging problems of the 21(st) century leading cause of and the fifth death worldwide. Substantial evidence suggests that T2D is a multifactorial disease with a strong genetic component. Recent genome-wide association studies (GWAS) have successfully identified and replicated nearly 75 susceptibility loci associated with T2D and related metabolic traits, mostly in Europeans, and some in African, and South Asian populations. The GWAS serve as a starting point for future genetic and functional studies since the mechanisms of action by which these associated loci influence disease is still unclear and it is difficult to predict potential implication of these findings in clinical settings. Despite extensive replication, no study has unequivocally demonstrated their clinical role in the disease management beyond progression to T2D from impaired glucose tolerance. However, these studies are revealing new molecular pathways underlying diabetes etiology, gene-environment interactions, epigenetic modifications, and gene function. This review highlights evolving progress made in the rapidly moving field of T2D genetics that is starting to unravel the pathophysiology of a complex phenotype and has potential to show clinical relevance in the near future.
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18
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Abstract
People vary genetically in their susceptibility to the effects of environmental risk factors for many diseases. Genetic variation also underlies the extent to which people respond appropriately to clinical therapies. Defining the basis to the interactions between the genome and the environment may help elucidate the biologic basis to diseases such as type 2 diabetes, as well as help target preventive therapies and treatments. This review examines 1) some of the most current evidence on gene × environment interactions in relation to type 2 diabetes; 2) outlines how the availability of information on gene × environment interactions might help improve the prevention and treatment of type 2 diabetes; and 3) discusses existing and emerging strategies that might enhance our ability to detect and exploit gene × environment interactions in complex disease traits.
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Affiliation(s)
- Paul W Franks
- Department of Clinical Sciences, Genetic & Molecular Epidemiology Unit, Skåne University Hospital Malmö, 205 02 Malmö, Sweden.
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19
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Altamura AC. From ‘classical’ antipsychotics to ‘multidimensional stabilizers’: do we need a new classification for novel drugs used in schizophrenia? ACTA ACUST UNITED AC 2011. [DOI: 10.2217/npy.11.58] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Duncan LE, Keller MC. A critical review of the first 10 years of candidate gene-by-environment interaction research in psychiatry. Am J Psychiatry 2011; 168:1041-9. [PMID: 21890791 PMCID: PMC3222234 DOI: 10.1176/appi.ajp.2011.11020191] [Citation(s) in RCA: 666] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Gene-by-environment interaction (G×E) studies in psychiatry have typically been conducted using a candidate G×E (cG×E) approach, analogous to the candidate gene association approach used to test genetic main effects. Such cG×E research has received widespread attention and acclaim, yet cG×E findings remain controversial. The authors examined whether the many positive cG×E findings reported in the psychiatric literature were robust or if, in aggregate, cG×E findings were consistent with the existence of publication bias, low statistical power, and a high false discovery rate. METHOD The authors conducted analyses on data extracted from all published studies (103 studies) from the first decade (2000-2009) of cG×E research in psychiatry. RESULTS Ninety-six percent of novel cG×E studies were significant compared with 27% of replication attempts. These findings are consistent with the existence of publication bias among novel cG×E studies, making cG×E hypotheses appear more robust than they actually are. There also appears to be publication bias among replication attempts because positive replication attempts had smaller average sample sizes than negative ones. Power calculations using observed sample sizes suggest that cG×E studies are underpowered. Low power along with the likely low prior probability of a given cG×E hypothesis being true suggests that most or even all positive cG×E findings represent type I errors. CONCLUSIONS In this new era of big data and small effects, a recalibration of views about groundbreaking findings is necessary. Well-powered direct replications deserve more attention than novel cG×E findings and indirect replications.
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Li J, Zhang K, Yi N. A Bayesian hierarchical model for detecting haplotype-haplotype and haplotype-environment interactions in genetic association studies. Hum Hered 2011; 71:148-60. [PMID: 21778734 DOI: 10.1159/000324841] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 02/03/2011] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Genetic association studies based on haplotypes are powerful in the discovery and characterization of the genetic basis of complex human diseases. However, statistical methods for detecting haplotype-haplotype and haplotype-environment interactions have not yet been fully developed owing to the difficulties encountered: large numbers of potential haplotypes and unknown haplotype pairs. Furthermore, methods for detecting the association between rare haplotypes and disease have not kept pace with their counterpart of common haplotypes. METHODS/RESULTS We herein propose an efficient and robust method to tackle these problems based on a Bayesian hierarchical generalized linear model. Our model simultaneously fits environmental effects, main effects of numerous common and rare haplotypes, and haplotype-haplotype and haplotype-environment interactions. The key to the approach is the use of a continuous prior distribution on coefficients that favors sparseness in the fitted model and facilitates computation. We develop a fast expectation-maximization algorithm to fit models by estimating posterior modes of coefficients. We incorporate our algorithm into the iteratively weighted least squares for classical generalized linear models as implemented in the R package glm. We evaluate the proposed method and compare its performance to existing methods on extensive simulated data. CONCLUSION The results show that the proposed method performs well under all situations and is more powerful than existing approaches.
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Affiliation(s)
- Jun Li
- Department of Biostatistics, Section on Statistical Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0022, USA
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22
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Murcray CE, Lewinger JP, Conti DV, Thomas DC, Gauderman WJ. Sample size requirements to detect gene-environment interactions in genome-wide association studies. Genet Epidemiol 2011; 35:201-10. [PMID: 21308767 DOI: 10.1002/gepi.20569] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 01/05/2011] [Accepted: 01/10/2011] [Indexed: 11/07/2022]
Abstract
Many complex diseases are likely to be a result of the interplay of genes and environmental exposures. The standard analysis in a genome-wide association study (GWAS) scans for main effects and ignores the potentially useful information in the available exposure data. Two recently proposed methods that exploit environmental exposure information involve a two-step analysis aimed at prioritizing the large number of SNPs tested to highlight those most likely to be involved in a GE interaction. For example, Murcray et al. ([2009] Am J Epidemiol 169:219–226) proposed screening on a test that models the G-E association induced by an interaction in the combined case-control sample. Alternatively, Kooperberg and LeBlanc ([2008] Genet Epidemiol 32:255–263) suggested screening on genetic marginal effects. In both methods, SNPs that pass the respective screening step at a pre-specified significance threshold are followed up with a formal test of interaction in the second step. We propose a hybrid method that combines these two screening approaches by allocating a proportion of the overall genomewide significance level to each test. We show that the Murcray et al. approach is often the most efficient method, but that the hybrid approach is a powerful and robust method for nearly any underlying model. As an example, for a GWAS of 1 million markers including a single true disease SNP with minor allele frequency of 0.15, and a binary exposure with prevalence 0.3, the Murcray, Kooperberg and hybrid methods are 1.90, 1.27, and 1.87 times as efficient, respectively, as the traditional case-control analysis to detect an interaction effect size of 2.0.
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Affiliation(s)
- Cassandra E Murcray
- Department of Preventive Medicine, University of Southern California, Los Angeles, California 90089-9010, USA.
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Otero S, Moreno-Iniguez M, Payá B, Castro-Fornieles J, Gonzalez-Pinto A, Baeza I, Mayoral M, Graell M, Arango-López C. Twelve-month follow-up of family communication and psychopathology in children and adolescents with a first psychotic episode (CAFEPS study). Psychiatry Res 2011; 185:72-7. [PMID: 20580840 DOI: 10.1016/j.psychres.2009.12.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 10/13/2009] [Accepted: 12/15/2009] [Indexed: 12/01/2022]
Abstract
We analyzed the potential influence of family relationships and history of psychiatric disorders on the presentation and course of early psychotic disorders. We recruited 110 subjects aged 9-17 years with a first psychotic episode and 98 matched healthy controls, and followed them for 1 year. Data were collected through clinical interviews and the Parent-Adolescent Communication Inventory. A family history of psychosis-related disorders was more common in patients' families, with a five-fold higher risk for psychoses related disorders than families of healthy controls. If we consider psychoses related disorder in first-degree relatives, the risk is even higher, rising to 15-fold. The families of patients with a first psychotic episode score themselves worse in communication than the families of healthy controls. More problems in communication at baseline correlated with a higher degree of psychopathology and a lower clinical improvement after 12 months of follow-up.
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Affiliation(s)
- Soraya Otero
- Child and Adolescent Mental Health Unit, Department of Psychiatry and Psychology, Hospital Universitario Marqués de Valdecilla, Santander, Spain.
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Abstract
Obesity (OMIM #601665) is a disease where excessive stores of body fat impact negatively on health. The first law of thermodynamics dictates that energy cannot be created or destroyed so if energy is taken into the body, but not transformed to ATP for metabolic work or dissipated as heat, it will be stored as fat. Therefore, the ultimate cause of obesity is a long-term positive energy imbalance [energy intake (EI) exceeds energy expenditure (EE)]. Despite this simple explanation, there is no single reason why EI may exceed EE meaning that the proximate causes of obesity are multi-factorial in origin involving a complex interplay of genetic, behavioural, and environmental influences on metabolism, diet, and activity.
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Affiliation(s)
- Laura M Johnson
- Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, UK.
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Clarke GM, Morris AP. A comparison of sample size and power in case-only association studies of gene-environment interaction. Am J Epidemiol 2010; 171:498-505. [PMID: 20047976 PMCID: PMC2816730 DOI: 10.1093/aje/kwp398] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Assuming continuous, normally distributed environmental and categorical genotype variables, the authors compare 6 case-only designs for tests of association in gene-environment interaction. Novel tests modeling the environmental variable as either the response or the predictor and allowing a genetic variable with multiallelic variants are included. The authors show that tests imposing the same genotypic pattern of inheritance perform similarly regardless of whether genotype is the response variable or the predictor variable. The novel tests using the genetic variable as the response variable are advantageous because they are robust to non-normally distributed environmental exposures. Dominance deviance—deviation from additivity in the main or interaction effects—is key to test performance: When it is zero or modest, tests searching for a trend with increasing risk alleles are optimal; when it is large, tests for genotypic effects are optimal. However, the authors show that dominance deviance is attenuated when it is observed at a proxy locus, which is common in genome-wide association studies, so large dominance deviance is likely to be rare. The authors conclude that the trend test is the appropriate tool for large-scale association scans where the true gene-environment interaction model is unknown. The common practice of assuming a dominant pattern of inheritance can cause serious losses of power in the presence of any recessive, or modest dominant, effects.
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Affiliation(s)
- Geraldine M Clarke
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.
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Gravlee CC, Non AL, Mulligan CJ. Genetic ancestry, social classification, and racial inequalities in blood pressure in Southeastern Puerto Rico. PLoS One 2009; 4:e6821. [PMID: 19742303 PMCID: PMC2731885 DOI: 10.1371/journal.pone.0006821] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Accepted: 08/03/2009] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The role of race in human genetics and biomedical research is among the most contested issues in science. Much debate centers on the relative importance of genetic versus sociocultural factors in explaining racial inequalities in health. However, few studies integrate genetic and sociocultural data to test competing explanations directly. METHODOLOGY/PRINCIPAL FINDINGS We draw on ethnographic, epidemiologic, and genetic data collected in Southeastern Puerto Rico to isolate two distinct variables for which race is often used as a proxy: genetic ancestry versus social classification. We show that color, an aspect of social classification based on the culturally defined meaning of race in Puerto Rico, better predicts blood pressure than does a genetic-based estimate of continental ancestry. We also find that incorporating sociocultural variables reveals a new and significant association between a candidate gene polymorphism for hypertension (alpha(2C) adrenergic receptor deletion) and blood pressure. CONCLUSIONS/SIGNIFICANCE This study addresses the recognized need to measure both genetic and sociocultural factors in research on racial inequalities in health. Our preliminary results provide the most direct evidence to date that previously reported associations between genetic ancestry and health may be attributable to sociocultural factors related to race and racism, rather than to functional genetic differences between racially defined groups. Our results also imply that including sociocultural variables in future research may improve our ability to detect significant allele-phenotype associations. Thus, measuring sociocultural factors related to race may both empower future genetic association studies and help to clarify the biological consequences of social inequalities.
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Affiliation(s)
- Clarence C Gravlee
- Department of Anthropology, University of Florida, Gainesville, Florida, United States of America.
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Abstract
Catalase (CAT) is part of the enzymatic defense system against reactive oxygen species (ROS), known to be involved in the pathogenesis of asbestosis. This study investigates whether CAT -262 C>T genetic polymorphism influences the risk of asbestosis in workers occupationally exposed to asbestos.The nested case-control study included 262 cases with asbestosis and 265 controls with no asbestos-related disease. Data on cumulative asbestos exposure and smoking were available. A real-time PCR assay was introduced for genotyping CAT -262 C>T promoter polymorphism.A slightly elevated risk of asbestosis was observed in subjects with the CAT -262 TT genotype compared to others (OR=1.36, CI 0.70-2.62). This risk did not change substantially after adjustment by sex, age, and smoking, but the involvement of cumulative asbestos exposure changed the OR to 1.91 (CI 0.93-3.91). These findings indicate that the CAT -262 TT genotype may be slightly associated with an increased risk of asbestosis. No synergistic effect was found between cumulative asbestos exposure and the CAT -262 TT genotype, but cumulative asbestos exposure acted as a confounder. These results are an important contribution to understanding the interactions between genetic and environmental factors that may modify the risk of asbestosis.
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van Os J, Rutten BPF, Poulton R. Gene-environment interactions in schizophrenia: review of epidemiological findings and future directions. Schizophr Bull 2008; 34:1066-82. [PMID: 18791076 PMCID: PMC2632485 DOI: 10.1093/schbul/sbn117] [Citation(s) in RCA: 408] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Concern is building about high rates of schizophrenia in large cities, and among immigrants, cannabis users, and traumatized individuals, some of which likely reflects the causal influence of environmental exposures. This, in combination with very slow progress in the area of molecular genetics, has generated interest in more complicated models of schizophrenia etiology that explicitly posit gene-environment interactions (EU-GEI. European Network of Schizophrenia Networks for the Study of Gene Environment Interactions. Schizophrenia aetiology: do gene-environment interactions hold the key? [published online ahead of print April 25, 2008] Schizophr Res; S0920-9964(08) 00170-9). Although findings of epidemiological gene-environment interaction (G x E) studies are suggestive of widespread gene-environment interactions in the etiology of schizophrenia, numerous challenges remain. For example, attempts to identify gene-environment interactions cannot be equated with molecular genetic studies with a few putative environmental variables "thrown in": G x E is a multidisciplinary exercise involving epidemiology, psychology, psychiatry, neuroscience, neuroimaging, pharmacology, biostatistics, and genetics. Epidemiological G x E studies using indirect measures of genetic risk in genetically sensitive designs have the advantage that they are able to model the net, albeit nonspecific, genetic load. In studies using direct molecular measures of genetic variation, a hypothesis-driven approach postulating synergistic effects between genes and environment impacting on a final common pathway, such as "sensitization" of mesolimbic dopamine neurotransmission, while simplistic, may provide initial focus and protection against the numerous false-positive and false-negative results that these investigations engender. Experimental ecogenetic approaches with randomized assignment may help to overcome some of the limitations of observational studies and allow for the additional elucidation of underlying mechanisms using a combination of functional enviromics and functional genomics.
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Affiliation(s)
- Jim van Os
- Department of Psychiatry and Neuropsychology, School of Mental Health and Neuroscience, Maastricht University Medical Centre, EURON, SEARCH, Maastricht, The Netherlands.
| | - Bart PF Rutten
- Department of Psychiatry and Neuropsychology, School of Mental Health and Neuroscience, Maastricht University Medical Centre, EURON, SEARCH, PO Box 616 (location DOT 10), Maastricht, 6200 MD, The Netherlands
| | - Richie Poulton
- Dunedin Multidisciplinary Health and Development Research Unit, Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, PO Box 913, Dunedin, New Zealand
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Abstract
PURPOSE OF REVIEW We examine the reasons for investigating gene-environment interactions and address recent reports evaluating interactions between genes and environmental modulators in relation to cardiovascular disease and its common risk factors. RECENT FINDINGS Studies focusing on smoking, physical activity, and alcohol and coffee consumption are observational and include relatively large sample sizes. They tend to examine single genes, however, and fail to address interactions with other genes and other correlated environmental factors. Studies examining gene-diet interactions include both observational and interventional designs. These studies are smaller, especially those including dietary interventions. Among the reported gene-diet interactions, it is important to highlight the strengthened position of APOA5 as a major gene that is involved in triglyceride metabolism and modulated by dietary factors, and the identification of APOA2 as a modulator of food intake and obesity risk. SUMMARY The study of gene-environment interactions is an active and much needed area of research. Although technical barriers of genetic studies are rapidly being overcome, inclusion of comprehensive and reliable environmental information represents a significant shortcoming of genetics studies. Progress in this area requires inclusion of larger populations but also more comprehensive, standardized, and precise approaches to capturing environmental information.
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Affiliation(s)
- Jose M Ordovas
- Nutrition and Genomics Laboratory, JM-USDA Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts 02111, USA.
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