1
|
Wang B, Irizar H, Thygesen JH, Zartaloudi E, Austin-Zimmerman I, Bhat A, Harju-Seppänen J, Pain O, Bass N, Gkofa V, Alizadeh BZ, van Amelsvoort T, Arranz MJ, Bender S, Cahn W, Stella Calafato M, Crespo-Facorro B, Di Forti M, Giegling I, de Haan L, Hall J, Hall MH, van Haren N, Iyegbe C, Kahn RS, Kravariti E, Lawrie SM, Lin K, Luykx JJ, Mata I, McDonald C, McIntosh AM, Murray RM, Picchioni M, Powell J, Prata DP, Rujescu D, Rutten BPF, Shaikh M, Simons CJP, Toulopoulou T, Weisbrod M, van Winkel R, Kuchenbaecker K, McQuillin A, Bramon E. Psychosis Endophenotypes: A Gene-Set-Specific Polygenic Risk Score Analysis. Schizophr Bull 2023; 49:1625-1636. [PMID: 37582581 PMCID: PMC10686343 DOI: 10.1093/schbul/sbad088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
BACKGROUND AND HYPOTHESIS Endophenotypes can help to bridge the gap between psychosis and its genetic predispositions, but their underlying mechanisms remain largely unknown. This study aims to identify biological mechanisms that are relevant to the endophenotypes for psychosis, by partitioning polygenic risk scores into specific gene sets and testing their associations with endophenotypes. STUDY DESIGN We computed polygenic risk scores for schizophrenia and bipolar disorder restricted to brain-related gene sets retrieved from public databases and previous publications. Three hundred and seventy-eight gene-set-specific polygenic risk scores were generated for 4506 participants. Seven endophenotypes were also measured in the sample. Linear mixed-effects models were fitted to test associations between each endophenotype and each gene-set-specific polygenic risk score. STUDY RESULTS After correction for multiple testing, we found that a reduced P300 amplitude was associated with a higher schizophrenia polygenic risk score of the forebrain regionalization gene set (mean difference per SD increase in the polygenic risk score: -1.15 µV; 95% CI: -1.70 to -0.59 µV; P = 6 × 10-5). The schizophrenia polygenic risk score of forebrain regionalization also explained more variance of the P300 amplitude (R2 = 0.032) than other polygenic risk scores, including the genome-wide polygenic risk scores. CONCLUSIONS Our finding on reduced P300 amplitudes suggests that certain genetic variants alter early brain development thereby increasing schizophrenia risk years later. Gene-set-specific polygenic risk scores are a useful tool to elucidate biological mechanisms of psychosis and endophenotypes, offering leads for experimental validation in cellular and animal models.
Collapse
Affiliation(s)
- Baihan Wang
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Haritz Irizar
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Johan H Thygesen
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Institute of Health Informatics, University College London, London, UK
| | - Eirini Zartaloudi
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Isabelle Austin-Zimmerman
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Anjali Bhat
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Jasmine Harju-Seppänen
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Oliver Pain
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Nick Bass
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Vasiliki Gkofa
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Behrooz Z Alizadeh
- University of Groningen, University Medical Center Groningen, University Center for Psychiatry, Rob Giel Research Center, Groningen, The Netherlands
- Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Therese van Amelsvoort
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Maria J Arranz
- Fundació Docència i Recerca Mutua Terrassa, Terrassa, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Institut de Recerca Biomédica Sant Pau (IIB-Sant Pau), Barcelona, Spain
| | - Stephan Bender
- Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Wiepke Cahn
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Altrecht, General Mental Health Care, Utrecht, The Netherlands
| | - Maria Stella Calafato
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Benedicto Crespo-Facorro
- CIBERSAM, Centro Investigación Biomédica en Red Salud Mental, Sevilla, Spain
- Department of Psychiatry, University Hospital Virgen del Rocio, School of Medicine, University of Sevilla–IBiS, Sevilla, Spain
| | - Marta Di Forti
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | | | - Ina Giegling
- Comprehensive Centers for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Austria
| | - Lieuwe de Haan
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Arkin, Institute for Mental Health, Amsterdam, The Netherlands
| | - Jeremy Hall
- Neuroscience and Mental Health Innovation Institute, School of Medicine, Cardiff University, Hadyn Ellis Building, Mandy Road, Cardiff, UK
| | - Mei-Hua Hall
- Psychosis Neurobiology Laboratory, Harvard Medical School, McLean Hospital, Belmont, MA, USA
| | - Neeltje van Haren
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Center, Sophia’s Children Hospital, Rotterdam, The Netherlands
| | - Conrad Iyegbe
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - René S Kahn
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Eugenia Kravariti
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Stephen M Lawrie
- Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, UK
| | - Kuang Lin
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Jurjen J Luykx
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ignacio Mata
- Fundacion Argibide, Pamplona, Spain
- CIBERSAM, Centro Investigación Biomédica en Red Salud Mental, Madrid, Spain
| | - Colm McDonald
- The Centre for Neuroimaging & Cognitive Genomics (NICOG) and NCBES Galway Neuroscience Centre, University of Galway, Galway, Ireland
| | - Andrew M McIntosh
- Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Robin M Murray
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | | | - Marco Picchioni
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- St Magnus Hospital, Surrey, UK
| | - John Powell
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Diana P Prata
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciencias da Universidade de Lisboa, Portugal
| | - Dan Rujescu
- Department of Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Division of General Psychiatry, Medical University of Vienna, Austria
| | - Bart P F Rutten
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Madiha Shaikh
- North East London Foundation Trust, London, UK
- Research Department of Clinical, Educational and Health Psychology, University College London, London, UK
| | - Claudia J P Simons
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- GGzE Institute for Mental Health Care, Eindhoven, The Netherlands
| | - Timothea Toulopoulou
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Türkiye
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Türkiye
- Department of Psychology, Bilkent University, Ankara, Türkiye
- School of Medicine, Department of Psychiatry, National and Kapodistrian University of Athens, Athens, Greece
- Department of Psychiatry and Behavioral Health System, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Matthias Weisbrod
- Department of General Psychiatry, Center of Psychosocial Medicine, University of Heidelberg, Germany
- SRH Klinikum, Karlsbad-Langensteinbach, Germany
| | - Ruud van Winkel
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- KU Leuven, Department of Neuroscience, Research Group Psychiatry, Leuven, Belgium
| | - Karoline Kuchenbaecker
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- UCL Genetics Institute, Division of Biosciences, University College London, London, UK
| | - Andrew McQuillin
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
| | - Elvira Bramon
- Department of Mental Health Neuroscience, Division of Psychiatry, University College London, London, UK
- Institute of Cognitive Neuroscience, University College London, London, UK
| |
Collapse
|
2
|
Li W, Mao Z, Bo Q, Sun Y, Wang Z, Wang C. Prepulse inhibition in first-degree relatives of schizophrenia patients: A systematic review. Early Interv Psychiatry 2021; 15:652-661. [PMID: 32567764 DOI: 10.1111/eip.13003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/15/2020] [Accepted: 05/24/2020] [Indexed: 12/27/2022]
Abstract
BACKGROUND Prepulse inhibition (PPI) is a measure of sensorimotor gating used to identify deficits in early-stage information processing and inhibitory function defects. Many studies support the presence of PPI deficits in schizophrenia patients. However, very few studies have explored PPI levels among first-degree relatives (FDR) of schizophrenia patients, and the results have been inconsistent. This review article explored PPI levels in FDR of schizophrenia patients. METHODS We performed a systematic literature review using the PubMed, Cochrane, Embase, EBSCO and Chinese databases from inception to January 2020. A series of related factors (eg, PPI paradigm, heritability and sample characteristics) and outcomes were summarized from the literature that met the inclusion criteria. The Newcastle-Ottawa Scale was used to assess the quality of the included studies. RESULTS A total of eight studies were eligible for systematic review after screening. A meta-analysis of the selected studies was not conducted due to the limitations of quantity and paradigm heterogeneity. A majority of the studies' subjects were siblings of schizophrenia patients and different paradigms were applied. Most of the included studies reported no difference in PPI values between FDR of schizophrenia patients and healthy controls. CONCLUSION Contrary to traditional certainty that unaffected FDR of schizophrenia patients have PPI defects, our review found no sufficient evidence supporting that the PPI level in FDR of schizophrenia patients was lower than in healthy controls. A prospective cohort study focusing on different outcomes such as developing schizophrenia is required to explore PPI levels in FDR of schizophrenia patients.
Collapse
Affiliation(s)
- Weidi Li
- The National Clinical Research Center for Mental Disorders & Beijing Key Laboratory of Mental Disorders & Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Zhen Mao
- The National Clinical Research Center for Mental Disorders & Beijing Key Laboratory of Mental Disorders & Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Qijing Bo
- The National Clinical Research Center for Mental Disorders & Beijing Key Laboratory of Mental Disorders & Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Yue Sun
- The National Clinical Research Center for Mental Disorders & Beijing Key Laboratory of Mental Disorders & Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Zhimin Wang
- The National Clinical Research Center for Mental Disorders & Beijing Key Laboratory of Mental Disorders & Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Chuanyue Wang
- The National Clinical Research Center for Mental Disorders & Beijing Key Laboratory of Mental Disorders & Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| |
Collapse
|
3
|
Rovný R, Besterciová D, Riečanský I. Genetic Determinants of Gating Functions: Do We Get Closer to Understanding Schizophrenia Etiopathogenesis? Front Psychiatry 2020; 11:550225. [PMID: 33324248 PMCID: PMC7723973 DOI: 10.3389/fpsyt.2020.550225] [Citation(s) in RCA: 2] [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: 04/08/2020] [Accepted: 10/12/2020] [Indexed: 11/13/2022] Open
Abstract
Deficits in the gating of sensory stimuli, i.e., the ability to suppress the processing of irrelevant sensory input, are considered to play an important role in the pathogenesis of several neuropsychiatric disorders, in particular schizophrenia. Gating is disrupted both in schizophrenia patients and their unaffected relatives, suggesting that gating deficit may represent a biomarker associated with a genetic liability to the disorder. To assess the strength of the evidence for the etiopathogenetic links between genetic variation, gating efficiency, and schizophrenia, we carried out a systematic review of human genetic association studies of sensory gating (suppression of the P50 component of the auditory event-related brain potential) and sensorimotor gating (prepulse inhibition of the acoustic startle response). Sixty-three full-text articles met the eligibility criteria for inclusion in the review. In total, 117 genetic variants were reported to be associated with gating functions: 33 variants for sensory gating, 80 variants for sensorimotor gating, and four variants for both sensory and sensorimotor gating. However, only five of these associations (four for prepulse inhibition-CHRNA3 rs1317286, COMT rs4680, HTR2A rs6311, and TCF4 rs9960767, and one for P50 suppression-CHRNA7 rs67158670) were consistently replicated in independent samples. Although these variants and genes were all implicated in schizophrenia in research studies, only two polymorphisms (HTR2A rs6311 and TCF4 rs9960767) were also reported to be associated with schizophrenia at a meta-analytic or genome-wide level of evidence. Thus, although gating is widely considered as an important endophenotype of schizophrenia, these findings demonstrate that evidence for a common genetic etiology of impaired gating functions and schizophrenia is yet unsatisfactory, warranting further studies in this field.
Collapse
Affiliation(s)
- Rastislav Rovný
- Department of Behavioural Neuroscience, Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Dominika Besterciová
- Department of Behavioural Neuroscience, Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Igor Riečanský
- Department of Behavioural Neuroscience, Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
| |
Collapse
|
4
|
Habtewold TD, Liemburg EJ, Islam MA, de Zwarte SMC, Boezen HM, Bruggeman R, Alizadeh BZ. Association of schizophrenia polygenic risk score with data-driven cognitive subtypes: A six-year longitudinal study in patients, siblings and controls. Schizophr Res 2020; 223:135-147. [PMID: 32631699 DOI: 10.1016/j.schres.2020.05.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 03/23/2020] [Accepted: 05/06/2020] [Indexed: 12/12/2022]
Abstract
Cross-sectional studies have shown that the polygenic risk score for schizophrenia (PRSSCZ) may influence heterogeneity in cognitive performance although evidence from family-based longitudinal study is limited. This study aimed to identify trajectories of cognitive function and assess whether the PRSSCZ is associated with baseline cognitive performance and predicted six-year trajectories. We included 1119 patients with a schizophrenia spectrum disorder, and 1059 unaffected siblings and 586 unrelated controls who are eligible at baseline. Genotype data were collected at baseline, whereas clinical and sociodemographic data were collected at baseline, three and six years. Group-based trajectory modeling was applied on a weighted standardized composite score of general cognition to unravel cognitive subtypes and explore trajectories over time. We followed a standard procedure to calculate the polygenic risk score. A random-effects ordinal regression model was used to investigate the association between PRSSCZ and cognitive subtypes. Five cognitive subtypes with variable trajectories were found in patients, four in siblings and controls, and six in all combined samples. PRSSCZ significantly predicted poor cognitive trajectories in patients, siblings and all samples. After Bonferroni correction and adjustment for non-genetic factors, only the results in all combined sample remained significant. Cognitive impairment in schizophrenia is heterogeneous and may be linked with high PRSSCZ. Our finding confirmed at least in all combined samples the presence of genetic overlap between schizophrenia and cognitive function and can give insight into the mechanisms of cognitive deficits.
Collapse
Affiliation(s)
- Tesfa Dejenie Habtewold
- University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, University Center for Psychiatry, Rob Giel Research Center, Groningen, the Netherlands.
| | - Edith J Liemburg
- University of Groningen, University Medical Center Groningen, University Center for Psychiatry, Rob Giel Research Center, Groningen, the Netherlands
| | - Md Atiqul Islam
- Shahjalal University of Science and Technology, Department of Statistics, Sylhet 3114, Bangladesh
| | - Sonja M C de Zwarte
- Utrecht University, University Medical Center Utrecht, Brain Center Rudolf Magnus, Department of Psychiatry, Utrecht, Netherlands
| | - H Marike Boezen
- University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen, the Netherlands
| | | | - Richard Bruggeman
- University of Groningen, University Medical Center Groningen, University Center for Psychiatry, Rob Giel Research Center, Groningen, the Netherlands; University of Groningen, Faculty of Behavioural and Social Sciences, Department of Clinical and Developmental Neuropsychology, Groningen, the Netherlands.
| | - Behrooz Z Alizadeh
- University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, University Center for Psychiatry, Rob Giel Research Center, Groningen, the Netherlands
| |
Collapse
|
5
|
Lanillos P, Oliva D, Philippsen A, Yamashita Y, Nagai Y, Cheng G. A review on neural network models of schizophrenia and autism spectrum disorder. Neural Netw 2020; 122:338-363. [DOI: 10.1016/j.neunet.2019.10.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 09/18/2019] [Accepted: 10/23/2019] [Indexed: 02/07/2023]
|
6
|
Giagulli VA, Campone B, Castellana M, Salzano C, Fisher AD, de Angelis C, Pivonello R, Colao A, Pasquali D, Maggi M, Triggiani V, On Behalf Of The Klinefelter ItaliaN Group King. Neuropsychiatric Aspects in Men with Klinefelter Syndrome. Endocr Metab Immune Disord Drug Targets 2019; 19:109-115. [PMID: 29972105 PMCID: PMC7360906 DOI: 10.2174/1871530318666180703160250] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/06/2018] [Accepted: 05/07/2018] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND OBJECTIVE Klinefelter Syndrome (KS) is the most common sex chromosome aneuploidy (47, XXY) and cause of male hypergonadotropic hypogonadism. It is characterized by an extreme clinical heterogeneity in presentation, including infertility, hypogonadism, language delay, metabolic comorbidities, and neurocognitive and psychiatric disorders. Since testosterone is known to have organizational, neurotrophic and neuroprotective effects on brain, the condition of primary hypogonadism could play a role. Moreover, given that KS subjects have an additional X, genes on the extra-chromosome could also exert a significant impact. The aim of this narrative review is to analyze the available literature on the relationship between KS and neuropsychiatric disorders. METHODS To extend to the best of published literature on the topic, appropriate keywords and MeSH terms were identified and searched in Pubmed. Finally, references of original articles and reviews were examined. RESULTS Both morphological and functional studies focusing on the brain showed that there were important differences in brain structure of KS subjects. Different psychiatric disorders such as Schizophrenia, autism, attention deficit hyperactivity disorder, depression and anxiety were frequently reported in KS patients according to a broad spectrum of phenotypes. T supplementation (TRT) was not able to improve the psychotic disorders in KS men with or without overt hypogonadism. CONCLUSION Although the risk of psychosis, depression and autism is increased in subjects with KS, no definitive evidence has been found in studies aiming at identifying the relationship between aneuploidy, T deficit and the risk of psychiatric and cognitive disorders in subjects affected by KS.
Collapse
Affiliation(s)
- Vito Angelo Giagulli
- Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, Interdisciplinary Department of Medicine, University of Bari, School of Medicine, Policlinico, Bari, Italy
| | - Beatrice Campone
- Psychiatric Unit Department of Health Science, University of Florence, Italy
| | | | - Ciro Salzano
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Universita "Federico II" di Napoli, Naples, Italy
| | - Alessandra Daphne Fisher
- Sexual Medicine and Andrology Unit, Department of Experimental Clinical and Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Cristina de Angelis
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Universita "Federico II" di Napoli, Naples, Italy
| | - Rosario Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Universita "Federico II" di Napoli, Naples, Italy
| | - Annamaria Colao
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Universita "Federico II" di Napoli, Naples, Italy
| | - Daniela Pasquali
- Department of Medical, Surgical, Neurological, Metabolic Sciences and Aging, University of Campania "Luigi Vanvitelli", 80138 Naples, Italy
| | - Mario Maggi
- Sexual Medicine and Andrology Unit, Department of Experimental Clinical and Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Vincenzo Triggiani
- Section of Internal Medicine, Geriatrics, Endocrinology and Rare Diseases, Interdisciplinary Department of Medicine, University of Bari, School of Medicine, Policlinico, Bari, Italy
| | | |
Collapse
|
7
|
Abstract
Schizophrenia (SZ) is a severe psychotic disorder that is highly heritable and common in the general population. The genetic heterogeneity of SZ is substantial, with contributions from common, rare, and de novo variants, in addition to environmental factors. Large genome-wide association studies have detected many variants that are associated with SZ, yet the pathways by which these variants influence risk remain largely unknown. SZ is also clinically heterogeneous, with patients exhibiting a broad range of deficits and symptom severity that vary over the course of illness and treatment, which has complicated efforts to identify risk variants. However, the underlying brain dysfunction forms a more stable trait marker that quantitative neurocognitive and neurophysiological endophenotypes may be able to objectively measure. These endophenotypes are less likely to be heterogeneous than the disorder and provide a neurobiological context to detect risk variants and underlying pathways among genes associated with SZ diagnosis. Furthermore, many endophenotypes are translational into animal model systems, allowing for direct evaluation of the neural circuit dysfunctions and neurobiological substrates. We review a selection of the most promising SZ endophenotypes, including prepulse inhibition, mismatch negativity, oculomotor antisaccade, letter-number sequencing, and continuous performance tests. We also highlight recent findings from large consortia that suggest the potential role of genes, particularly in the neuregulin and glutamate pathways, in several of these endophenotypes. Although endophenotypes require additional time and effort to assess, the insight into the underlying neurobiology that they provide may ultimately reveal the underlying genetic architecture for SZ and suggest novel treatment targets.
Collapse
|
8
|
Hwang WJ, Lee TY, Shin WG, Kim M, Kim J, Lee J, Kwon JS. Global and Specific Profiles of Executive Functioning in Prodromal and Early Psychosis. Front Psychiatry 2019; 10:356. [PMID: 31178768 PMCID: PMC6537881 DOI: 10.3389/fpsyt.2019.00356] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/07/2019] [Indexed: 01/31/2023] Open
Abstract
Objective: Numerous reports on neurocognitive functioning deficits in individuals at clinical high risk (CHR) and first-episode psychosis (FEP) patients suggest particular deficits in executive functioning (EF). However, to date, most of the studies have administered a single or a few EF tests to participants, and few investigations have examined the different components of EF to identify specific subdomains of relative strength and weakness. Method: Forty CHR subjects, 85 FEP patients, and 85 healthy controls (HCs) were assessed with a neuropsychological battery to elucidate the profiles of EF in the subdomains of shift, attention, fluency, and planning. Results: In the subdomains of shift, attention, and fluency, CHR individuals and FEP patients showed deficits compared to HC. The post hoc analysis revealed that CHR individuals had comparable attention shifting and phonemic fluency compared to FEP. CHR showed intermediate deficits between FEP and HCs in spatial working memory and semantic fluency, and the largest effect size was observed in semantic fluency both for CHR and FEP. Conclusion: Overall, the findings of this study, in addition to providing detailed profiles of EF in prodromal and early psychosis patients, highlight the informative value of the specific subdomains of semantic fluency and spatial working memory.
Collapse
Affiliation(s)
- Wu Jeong Hwang
- Department of Brain and Cognitive Sciences, College of Natural Science, Seoul National University, Seoul, South Korea
| | - Tae Young Lee
- Department of Psychiatry, College of Medicine, Seoul National University, Seoul, South Korea
| | - Won-Gyo Shin
- Institute of Human Behavioral Medicine, SNU-MRC, Seoul, South Korea
| | - Minah Kim
- Department of Psychiatry, College of Medicine, Seoul National University, Seoul, South Korea.,Department of Neuropsychiatry, Seoul National University Hospital, Seoul, South Korea
| | - Jihyang Kim
- Department of Psychiatry, College of Medicine, Seoul National University, Seoul, South Korea
| | - Junhee Lee
- Department of Psychiatry, College of Medicine, Seoul National University, Seoul, South Korea.,Department of Neuropsychiatry, Seoul National University Hospital, Seoul, South Korea
| | - Jun Soo Kwon
- Department of Brain and Cognitive Sciences, College of Natural Science, Seoul National University, Seoul, South Korea.,Department of Psychiatry, College of Medicine, Seoul National University, Seoul, South Korea.,Department of Neuropsychiatry, Seoul National University Hospital, Seoul, South Korea.,Institute of Human Behavioral Medicine, SNU-MRC, Seoul, South Korea
| |
Collapse
|
9
|
Zhou HY, Li Z, Xie DJ, Xu T, Cheung EEF, Li H, Chan RCK. Heritability estimates of spatial working memory and set-shifting in a healthy Chinese twin sample: A preliminary study. Psych J 2018; 7:144-151. [DOI: 10.1002/pchj.227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 06/06/2018] [Accepted: 07/02/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Han-yu Zhou
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Department of Psychology; University of Chinese Academy of Sciences; Beijing China
- Department of Psychology; Renmin University of China; Beijing China
| | - Zhi Li
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Department of Psychology; University of Chinese Academy of Sciences; Beijing China
| | - Dong-jie Xie
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Department of Psychology; University of Chinese Academy of Sciences; Beijing China
| | - Ting Xu
- Key Laboratory of Behavioral Sciences and Magnetic Resonance Imaging Research Center; Institute of Psychology, Chinese Academy of Sciences; Beijing China
- Center for the Developing Brain; Child Mind Institute; New York New York USA
| | - Eric E. F. Cheung
- Castle Peak Hospital; Hong Kong Special Administrative Region; Tuen Mun China
| | - Huanhuan Li
- Department of Psychology; Renmin University of China; Beijing China
| | - Raymond C. K. Chan
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Department of Psychology; University of Chinese Academy of Sciences; Beijing China
| |
Collapse
|
10
|
Greenwood TA. Positive Traits in the Bipolar Spectrum: The Space between Madness and Genius. MOLECULAR NEUROPSYCHIATRY 2017; 2:198-212. [PMID: 28277566 PMCID: PMC5318923 DOI: 10.1159/000452416] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 10/10/2016] [Indexed: 01/25/2023]
Abstract
Bipolar disorder is a severe, lifelong mood disorder for which little is currently understood of the genetic mechanisms underlying risk. By examining related dimensional phenotypes, we may further our understanding of the disorder. Creativity has a historical connection with the bipolar spectrum and is particularly enhanced among unaffected first-degree relatives and those with bipolar spectrum traits. This suggests that some aspects of the bipolar spectrum may confer advantages, while more severe expressions of symptoms negatively influence creative accomplishment. Creativity is a complex, multidimensional construct with both cognitive and affective components, many of which appear to reflect a shared genetic vulnerability with bipolar disorder. It is suggested that a subset of bipolar risk variants confer advantages as positive traits according to an inverted-U-shaped curve with clinically unaffected allele carriers benefitting from the positive traits and serving to maintain the risk alleles in the population. The association of risk genes with creativity in healthy individuals (e.g., NRG1), as well as an overall sharing of common genetic variation between bipolar patients and creative individuals, provides support for this model. Current findings are summarized from a multidisciplinary perspective to demonstrate the feasibility of research in this area to reveal the mechanisms underlying illness.
Collapse
|
11
|
Iacono WG, Malone SM, Vrieze SI. Endophenotype best practices. Int J Psychophysiol 2017; 111:115-144. [PMID: 27473600 PMCID: PMC5219856 DOI: 10.1016/j.ijpsycho.2016.07.516] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 07/21/2016] [Accepted: 07/24/2016] [Indexed: 01/19/2023]
Abstract
This review examines the current state of electrophysiological endophenotype research and recommends best practices that are based on knowledge gleaned from the last decade of molecular genetic research with complex traits. Endophenotype research is being oversold for its potential to help discover psychopathology relevant genes using the types of small samples feasible for electrophysiological research. This is largely because the genetic architecture of endophenotypes appears to be very much like that of behavioral traits and disorders: they are complex, influenced by many variants (e.g., tens of thousands) within many genes, each contributing a very small effect. Out of over 40 electrophysiological endophenotypes covered by our review, only resting heart, a measure that has received scant advocacy as an endophenotype, emerges as an electrophysiological variable with verified associations with molecular genetic variants. To move the field forward, investigations designed to discover novel variants associated with endophenotypes will need extremely large samples best obtained by forming consortia and sharing data obtained from genome wide arrays. In addition, endophenotype research can benefit from successful molecular genetic studies of psychopathology by examining the degree to which these verified psychopathology-relevant variants are also associated with an endophenotype, and by using knowledge about the functional significance of these variants to generate new endophenotypes. Even without molecular genetic associations, endophenotypes still have value in studying the development of disorders in unaffected individuals at high genetic risk, constructing animal models, and gaining insight into neural mechanisms that are relevant to clinical disorder.
Collapse
|
12
|
Elvevåg B, Cohen AS, Wolters MK, Whalley HC, Gountouna V, Kuznetsova KA, Watson AR, Nicodemus KK. An examination of the language construct in NIMH's research domain criteria: Time for reconceptualization! Am J Med Genet B Neuropsychiatr Genet 2016; 171:904-19. [PMID: 26968151 PMCID: PMC5025728 DOI: 10.1002/ajmg.b.32438] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 02/11/2016] [Indexed: 12/25/2022]
Abstract
The National Institute of Mental Health's Research Domain Criteria (RDoC) Initiative "calls for the development of new ways of classifying psychopathology based on dimensions of observable behavior." As a result of this ambitious initiative, language has been identified as an independent construct in the RDoC matrix. In this article, we frame language within an evolutionary and neuropsychological context and discuss some of the limitations to the current measurements of language. Findings from genomics and the neuroimaging of performance during language tasks are discussed in relation to serious mental illness and within the context of caveats regarding measuring language. Indeed, the data collection and analysis methods employed to assay language have been both aided and constrained by the available technologies, methodologies, and conceptual definitions. Consequently, different fields of language research show inconsistent definitions of language that have become increasingly broad over time. Individually, they have also shown significant improvements in conceptual resolution, as well as in experimental and analytic techniques. More recently, language research has embraced collaborations across disciplines, notably neuroscience, cognitive science, and computational linguistics and has ultimately re-defined classical ideas of language. As we move forward, the new models of language with their remarkably multifaceted constructs force a re-examination of the NIMH RDoC conceptualization of language and thus the neuroscience and genetics underlying this concept. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Brita Elvevåg
- Department of Clinical MedicineUniversity of Tromsø−The Arctic University of NorwayTromsøNorway
- Norwegian Centre for eHealth ResearchUniversity Hospital of North NorwayTromsøNorway
| | - Alex S. Cohen
- Department of PsychologyLouisiana State UniversityBaton RougeLouisiana
| | - Maria K. Wolters
- School of InformaticsUniversity of EdinburghEdinburghUnited Kingdom
| | | | - Viktoria‐Eleni Gountouna
- Centre for Genomic and Experimental MedicineInstitute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Ksenia A. Kuznetsova
- Centre for Genomic and Experimental MedicineInstitute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Andrew R. Watson
- Division of PsychiatryUniversity of EdinburghEdinburghUnited Kingdom
| | - Kristin K. Nicodemus
- Centre for Genomic and Experimental MedicineInstitute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| |
Collapse
|
13
|
Abstract
BACKGROUND Prepulse inhibition (PPI) of the startle reflex has been suggested as a candidate endophenotype for schizophrenia research, as it shows high heritability and has been found deficient in schizophrenia spectrum disorders. The objectives of the study were to 1) identify common genetic variants associated with baseline startle and PPI; 2) estimate the single nucleotide polymorphism heritability; and 3) examine the relationship of polygenic score for schizophrenia with baseline startle and PPI. METHODS A cohort of healthy young male subjects (n = 1493) originating from the Learning on Genetics of Schizophrenia Spectrum project was assessed for baseline startle and PPI. The most recent genome-wide association study in schizophrenia from the Psychiatric Genomics Consortium 2 was used to calculate polygenic scores. RESULTS Eleven loci showed suggestive association (p < 10(-6)) with baseline startle and PPI in the discovery cohort. Additional genotyping in a replication cohort identified genome-wide significant association at two loci (rs61810702 and rs4718984). These loci were co-localized with expression quantitative trait loci associated with gene expression of nerve growth factor (NGF) and calneuron 1 (CALN1) genes. Estimation of the genetic and environmental contributions to baseline startle and PPI showed a substantial single nucleotide polymorphism heritability for 120-ms PPI stimuli. Increased polygenic risk score for schizophrenia was associated with reduced PPI. CONCLUSIONS Common genetic variation has an important role in the etiology of schizophrenia and PPI impairments. Overall, these data support the idea that PPI is a valid endophenotype that can be used to explore the genetic architecture of schizophrenia.
Collapse
|
14
|
Greenwood TA, Light GA, Swerdlow NR, Calkins ME, Green MF, Gur RE, Gur RC, Lazzeroni LC, Nuechterlein KH, Olincy A, Radant AD, Seidman LJ, Siever LJ, Silverman JM, Stone WS, Sugar CA, Tsuang DW, Tsuang MT, Turetsky BI, Freedman R, Braff DL. Gating Deficit Heritability and Correlation With Increased Clinical Severity in Schizophrenia Patients With Positive Family History. Am J Psychiatry 2016; 173:385-91. [PMID: 26441157 PMCID: PMC4933520 DOI: 10.1176/appi.ajp.2015.15050605] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The Consortium on the Genetics of Schizophrenia Family Study evaluated 12 primary and other supplementary neurocognitive and neurophysiological endophenotypes in schizophrenia probands and their families. Previous analyses of prepulse inhibition (PPI) and P50 gating measures in this sample revealed heritability estimates that were lower than expected based on earlier family studies. Here the authors investigated whether gating measures were more heritable in multiply affected families with a positive family history compared with families with only a single affected proband (singleton). METHOD A total of 296 nuclear families consisting of a schizophrenia proband, at least one unaffected sibling, and both parents underwent a comprehensive endophenotype and clinical characterization. The Family Interview for Genetic Studies was administered to all participants and used to obtain convergent psychiatric symptom information for additional first-degree relatives. Among the families, 97 were multiply affected, and 96 were singletons. RESULTS Both PPI and P50 gating displayed substantially increased heritability in the 97 multiply affected families (47% and 36%, respectively) compared with estimates derived from the entire sample of 296 families (29% and 20%, respectively). However, no evidence for heritability was observed for either measure in the 96 singleton families. Schizophrenia probands derived from the multiply affected families also displayed a significantly increased severity of clinical symptoms compared with those from singleton families. CONCLUSIONS PPI and P50 gating measures demonstrate substantially increased heritability in schizophrenia families with a higher genetic vulnerability for illness, providing further support for the commonality of genes underlying both schizophrenia and gating measures.
Collapse
Affiliation(s)
| | - Gregory A. Light
- Department of Psychiatry, University of California San Diego, La Jolla, CA,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System
| | - Neal R. Swerdlow
- Department of Psychiatry, University of California San Diego, La Jolla, CA
| | - Monica E. Calkins
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA
| | - Michael F. Green
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA,VA Greater Los Angeles Healthcare System, Los Angeles, CA
| | - Raquel E. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA
| | - Ruben C. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA
| | - Laura C. Lazzeroni
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA
| | - Keith H. Nuechterlein
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA
| | - Ann Olincy
- Department of Psychiatry, University of Colorado Health Sciences Center, Denver, CO
| | - Allen D. Radant
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA,VA Puget Sound Health Care System, Seattle, WA
| | - Larry J. Seidman
- Department of Psychiatry, Harvard Medical School, Boston, MA,Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Boston, MA
| | - Larry J. Siever
- Department of Psychiatry, The Mount Sinai School of Medicine, New York, NY,James J. Peters VA Medical Center, New York, NY
| | - Jeremy M. Silverman
- Department of Psychiatry, The Mount Sinai School of Medicine, New York, NY,James J. Peters VA Medical Center, New York, NY
| | - William S. Stone
- Department of Psychiatry, Harvard Medical School, Boston, MA,Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Boston, MA
| | - Catherine A. Sugar
- Department of Biostatistics, University of California Los Angeles School of Public Health, Los Angeles, CA
| | - Debby W. Tsuang
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA,VA Puget Sound Health Care System, Seattle, WA
| | - Ming T. Tsuang
- Department of Psychiatry, University of California San Diego, La Jolla, CA,Center for Behavioral Genomics, and Institute for Genomic Medicine, University of California San Diego, La Jolla, CA,Harvard Institute of Psychiatric Epidemiology and Genetics, Boston, MA
| | - Bruce I. Turetsky
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA
| | - Robert Freedman
- Department of Psychiatry, University of Colorado Health Sciences Center, Denver, CO
| | - David L. Braff
- Department of Psychiatry, University of California San Diego, La Jolla, CA,VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System
| |
Collapse
|
15
|
Bo S, Haahr UH. Early-Onset Psychosis and Child and Adolescent Schizophrenia. Scand J Child Adolesc Psychiatr Psychol 2015. [DOI: 10.21307/sjcapp-2016-001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Sune Bo
- Psychiatric Research Unit , Region Zealand , Denmark
| | | |
Collapse
|
16
|
Reciprocal causation models of cognitive vs volumetric cerebral intermediate phenotypes for schizophrenia in a pan-European twin cohort. Mol Psychiatry 2015; 20:1386-96. [PMID: 25450228 DOI: 10.1038/mp.2014.152] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 09/01/2014] [Accepted: 10/06/2014] [Indexed: 01/13/2023]
Abstract
In aetiologically complex illnesses such as schizophrenia, there is no direct link between genotype and phenotype. Intermediate phenotypes could help clarify the underlying biology and assist in the hunt for genetic vulnerability variants. We have previously shown that cognition shares substantial genetic variance with schizophrenia; however, it is unknown if this reflects pleiotropic effects, direct causality or some shared third factor that links both, for example, brain volume (BV) changes. We quantified the degree of net genetic overlap and tested the direction of causation between schizophrenia liability, brain structure and cognition in a pan-European schizophrenia twin cohort consisting of 1243 members from 626 pairs. Cognitive deficits lie upstream of the liability for schizophrenia with about a quarter of the variance in liability to schizophrenia explained by variation in cognitive function. BV changes lay downstream of schizophrenia liability, with 4% of BV variation explained directly by variation in liability. However, our power to determine the nature of the relationship between BV deviation and schizophrenia liability was more limited. Thus, while there was strong evidence that cognitive impairment is causal to schizophrenia liability, we are not in a position to make a similar statement about the relationship between liability and BV. This is the first study to demonstrate that schizophrenia liability is expressed partially through cognitive deficits. One prediction of the finding that BV changes lie downstream of the disease liability is that the risk loci that influence schizophrenia liability will thereafter influence BV and to a lesser extent. By way of contrast, cognitive function lies upstream of schizophrenia, thus the relevant loci will actually have a larger effect size on cognitive function than on schizophrenia. These are testable predictions.
Collapse
|
17
|
Investigation of genetic variants in ubiquitin enzyme genes involved in the modulation of neurodevelopmental processes: a role in schizophrenia susceptibility? Genet Res (Camb) 2014; 96:e15. [PMID: 25578144 DOI: 10.1017/s0016672314000184] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Despite extensive research during the last few decades, the etiology of schizophrenia remains unclear. Evidence of both genetic and environmental influences in the developmental profile of schizophrenia has grown, and due to the complexity of this disorder, a polygenic aspect has been associated with this neuropsychiatric pathology. Unfortunately, no diagnostic strategies based on biological measurement or genetic testing is currently available for schizophrenia. Gene-expression profiling and recent protein studies have shown a decrease in the expression of ubiquitin pathway proteins in the prefrontal cortex of schizophrenia patients. We have examined single nucleotide polymorphisms (or SNPs) within three genes from the ubiquitin protein system: the ubiquitin conjugating enzyme E2D1 (UBE2D1) gene, the E3 SUMO-protein ligase protein inhibitor of activated STAT 2 (PIAS2) gene, and the E3 ubiquitin ligase F-box and leucine-rich repeat protein 21 (FBXL21) gene, in a Caucasian case-control population for schizophrenia. After Bonferroni correction for multiple testing was applied, no significant associations were reported for any of the tested SNPs. Additional genetic analyses will be necessary to fully explore the role of these three genes in schizophrenia. Regarding the rising interest in ubiquitin-related proteins as a therapeutic target in other pathologies such as cancer, further research into the role of ubiquitin pathways in schizophrenia seems topical and timely.
Collapse
|
18
|
Nicodemus KK, Elvevåg B, Foltz PW, Rosenstein M, Diaz-Asper C, Weinberger DR. Category fluency, latent semantic analysis and schizophrenia: a candidate gene approach. Cortex 2013; 55:182-91. [PMID: 24447899 DOI: 10.1016/j.cortex.2013.12.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 11/14/2013] [Accepted: 12/11/2013] [Indexed: 10/25/2022]
Abstract
BACKGROUND Category fluency is a widely used task that relies on multiple neurocognitive processes and is a sensitive assay of cortical dysfunction, including in schizophrenia. The test requires naming of as many words belonging to a certain category (e.g., animals) as possible within a short period of time. The core metrics are the overall number of words produced and the number of errors, namely non-members generated for a target category. We combine a computational linguistic approach with a candidate gene approach to examine the genetic architecture of this traditional fluency measure. METHODS In addition to the standard metric of overall word count, we applied a computational approach to semantics, Latent Semantic Analysis (LSA), to analyse the clustering pattern of the categories generated, as it likely reflects the search in memory for meanings. Also, since fluency performance probably also recruits verbal learning and recall processes, we included two standard measures of this cognitive process: the Wechsler Memory Scale and California Verbal Learning Test (CVLT). To explore the genetic architecture of traditional and LSA-derived fluency measures we employed a candidate gene approach focused on SNPs with known function that were available from a recent genome-wide association study (GWAS) of schizophrenia. The selected candidate genes were associated with language and speech, verbal learning and recall processes, and processing speed. A total of 39 coding SNPs were included for analysis in 665 subjects. RESULTS AND DISCUSSION Given the modest sample size, the results should be regarded as exploratory and preliminary. Nevertheless, the data clearly illustrate how extracting the meaning from participants' responses, by analysing the actual content of words, generates useful and neurocognitively viable metrics. We discuss three replicated SNPs in the genes ZNF804A, DISC1 and KIAA0319, as well as the potential for computational analyses of linguistic and textual data in other genomics tasks.
Collapse
Affiliation(s)
- Kristin K Nicodemus
- Neuropsychiatric Genetics Group, Department of Psychiatry, Trinity Centre for Health Sciences, Trinity College Dublin, St James Hospital, Dublin, Ireland.
| | - Brita Elvevåg
- Psychiatry Research Group, Department of Clinical Medicine, University of Tromsø, Norway; Norwegian Centre for Integrated Care and Telemedicine (NST), University Hospital of North Norway, Tromsø, Norway
| | - Peter W Foltz
- Pearson Knowledge Technologies, Boulder, CO, USA; Institute for Cognitive Science, University of Colorado, Boulder, CO, USA
| | | | - Catherine Diaz-Asper
- Clinical Brain Disorders Branch, National Institute of Mental Health/NIH, Bethesda, MD, USA
| | - Daniel R Weinberger
- Clinical Brain Disorders Branch, National Institute of Mental Health/NIH, Bethesda, MD, USA; Lieber Institute for Brain Development, Baltimore, MD, USA; Departments of Psychiatry, Neurology, Neuroscience and The Institute of Genomic Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| |
Collapse
|
19
|
van den Berg L, Henneman P, Willems van Dijk K, Delemarre-van de Waal HA, Oostra BA, van Duijn CM, Janssens ACJW. Heritability of dietary food intake patterns. Acta Diabetol 2013; 50:721-6. [PMID: 22415036 PMCID: PMC3898132 DOI: 10.1007/s00592-012-0387-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 02/27/2012] [Indexed: 11/18/2022]
Abstract
The quality and quantity of food intake affect body weight, but little is known about the genetics of such human dietary intake patterns in relation to the genetics of BMI. We aimed to estimate the heritability of dietary intake patterns and genetic correlation with BMI in participants of the Erasmus Rucphen Family study. The study included 1,690 individuals (42 % men; age range, 19-92), of whom 41.4 % were overweight and 15.9 % were obese. Self-report questionnaires were used to assess the number of days (0-7) on which participants consumed vegetables, fruit, fruit juice, fish, unhealthy snacks, fastfood, and soft drinks. Principal component analysis was applied to examine the correlations between the questionnaire items and to generate dietary intake pattern scores. Heritability and the shared genetic and shared non-genetic (environmental) correlations were estimated using the family structure of the cohort. Principal component analysis suggested that the questionnaire items could be grouped in a healthy and unhealthy dietary intake pattern, explaining 22 and 18 % of the phenotypic variance, respectively. The dietary intake patterns had a heritability of 0.32 for the healthy and 0.27 for the unhealthy pattern. Genetic correlations between the dietary intake patterns and BMI were not significant, but we found a significant environmental correlation between the unhealthy dietary intake pattern and BMI. Specific dietary intake patterns are associated with the risk of obesity and are heritable traits. The genetic factors that determine specific dietary intake patterns do not significantly overlap with the genetic factors that determine BMI.
Collapse
Affiliation(s)
- Linda van den Berg
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Peter Henneman
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Ko Willems van Dijk
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- Department of General Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Ben A. Oostra
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Cornelia M. van Duijn
- Genetic-Epidemiology Unit, Department of Epidemiology and Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | |
Collapse
|
20
|
Mandl RCW, Brouwer RM, Cahn W, Kahn RS, Hulshoff Pol HE. Family-wise automatic classification in schizophrenia. Schizophr Res 2013; 149:108-11. [PMID: 23876264 DOI: 10.1016/j.schres.2013.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/05/2013] [Accepted: 07/01/2013] [Indexed: 01/08/2023]
Abstract
Automatic classification of individuals at increased risk for schizophrenia can become an important screening method that allows for early intervention based on disease markers, if proven to be sufficiently accurate. Conventional classification methods typically consider information from single subjects, thereby ignoring (heritable) features of the person's relatives. In this paper we show that the inclusion of these features can lead to an increase in classification accuracy from 0.54 to 0.72 using a support vector machine model. This inclusion of contextual information is especially useful in diseases where the classification features carry a heritable component.
Collapse
Affiliation(s)
- René C W Mandl
- Department of Psychiatry, University Medical Center Utrecht, Rudolf Magnus Institute of Neuroscience, The Netherlands.
| | | | | | | | | |
Collapse
|
21
|
de Leede-Smith S, Barkus E. A comprehensive review of auditory verbal hallucinations: lifetime prevalence, correlates and mechanisms in healthy and clinical individuals. Front Hum Neurosci 2013; 7:367. [PMID: 23882203 PMCID: PMC3712258 DOI: 10.3389/fnhum.2013.00367] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 06/25/2013] [Indexed: 12/27/2022] Open
Abstract
Over the years, the prevalence of auditory verbal hallucinations (AVHs) have been documented across the lifespan in varied contexts, and with a range of potential long-term outcomes. Initially the emphasis focused on whether AVHs conferred risk for psychosis. However, recent research has identified significant differences in the presentation and outcomes of AVH in patients compared to those in non-clinical populations. For this reason, it has been suggested that auditory hallucinations are an entity by themselves and not necessarily indicative of transition along the psychosis continuum. This review will examine the presentation of auditory hallucinations across the life span, as well as in various clinical groups. The stages described include childhood, adolescence, adult non-clinical populations, hypnagogic/hypnopompic experiences, high schizotypal traits, schizophrenia, substance induced AVH, AVH in epilepsy, and AVH in the elderly. In children, need for care depends upon whether the child associates the voice with negative beliefs, appraisals and other symptoms of psychosis. This theme appears to carry right through to healthy voice hearers in adulthood, in which a negative impact of the voice usually only exists if the individual has negative experiences as a result of their voice(s). This includes features of the voices such as the negative content, frequency, and emotional valence as well as anxiety and depression, independently or caused by voices presence. It seems possible that the mechanisms which maintain AVH in non-clinical populations are different from those which are behind AVH presentations in psychotic illness. For example, the existence of maladaptive coping strategies in patient populations is one significant difference between clinical and non-clinical groups which is associated with a need for care. Whether or not these mechanisms start out the same and have differential trajectories is not yet evidenced. Future research needs to focus on the comparison of underlying factors and mechanisms that lead to the onset of AVH in both patient and non-clinical populations.
Collapse
|
22
|
Goldberg X, Alemany S, Rosa A, Picchioni M, Nenadic I, Owens SF, Rijsdijk F, Rebollo I, Sauer H, Murray RM, Fañanás L, Toulopoulou T. Substantial genetic link between IQ and working memory: implications for molecular genetic studies on schizophrenia. the European twin study of schizophrenia (EUTwinsS). Am J Med Genet B Neuropsychiatr Genet 2013; 162B:413-8. [PMID: 23650229 DOI: 10.1002/ajmg.b.32158] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 03/13/2013] [Indexed: 12/12/2022]
Abstract
While evidence is accumulating to support specific neurocognitive deficits as putative endophenotypes for schizophrenia, the heritability of these deficits in healthy subjects and whether they share common genetic influences, is not well established. In the present study, 529 healthy adult twins from two centers within the European Twin Study Network on Schizophrenia (EUTwinsS) were assessed on two domains that are consistently found to be particularly compromised in schizophrenia. Specifically, Intellectual Quotient Score (IQ) and the Letter-Number Sequencing Test (LNS), a measure of working memory, were measured in all twins. Latent variable components were explored through structural equation modeling, and common genetic underpinnings were examined using bivariate analyses. Results showed that the phenotypic correlation between IQ and working memory was almost entirely attributed to shared genetic variance (95.5%). We discuss the potential use of a combined measure of IQ and working memory to improve the power of molecular studies in detecting the genetic mechanisms underlying schizophrenia.
Collapse
Affiliation(s)
- Ximena Goldberg
- Unitat d'Antropologia, Departament de Biologia Animal, Facultat de Biologia, Universitat de Barcelona, Institut de Biomedicina de la Universitat de Barcelona IBUB, Centro de Investigación Biomédica en Red de Salud Mental CIBERSAM, Barcelona, Spain.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Calkins ME, Ray A, Gur RC, Freedman R, Green MF, Greenwood TA, Light GA, Nuechterlein KH, Olincy A, Radant AD, Seidman LJ, Siever LJ, Silverman JM, Stone WS, Sugar C, Swerdlow NR, Tsuang DW, Tsuang MT, Turetsky BI, Braff DL, Lazzeroni LC, Gur RE. Sex differences in familiality effects on neurocognitive performance in schizophrenia. Biol Psychiatry 2013; 73:976-84. [PMID: 23395246 PMCID: PMC3954126 DOI: 10.1016/j.biopsych.2012.12.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/23/2012] [Accepted: 12/13/2012] [Indexed: 01/12/2023]
Abstract
BACKGROUND Numerous studies have documented that patients with schizophrenia show neurocognitive impairments, which are also heritable in schizophrenia families. In view of these findings, the current investigation tested the hypothesis that neurocognitive performance of schizophrenia probands can predict the neurocognitive performance of their unaffected family members. METHODS Participants (n=1967; schizophrenia=369; first-degree relatives=1072; community comparison subjects=526) in the Consortium on the Genetics of Schizophrenia were administered the Penn Computerized Neurocognitive Battery. RESULTS Consistent with prior work, probands showed significant neurocognitive impairment, and neurocognitive ability was significantly heritable across domains. On average, unaffected relatives did not differ from community comparison subjects in their neurocognitive performance. However, in six of seven domains, proband scores predicted the performance of their unaffected siblings. Male, but not female, proband performance was predictive of their unaffected relatives' (siblings and mothers) performance, most consistently in face memory and spatial processing. CONCLUSIONS Using a novel approach in which individual probands are paired with their respective unaffected relatives within each family, we found that male proband performance predicted both sister and brother performance, an effect that was most powerfully observed for face memory and spatial processing. Results suggest that the familial transmission of sexually dimorphic neurocognitive domains, in which a particular sex tends to show a performance advantage over the other, may not itself be sex specific in schizophrenia families.
Collapse
Affiliation(s)
- Monica E. Calkins
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania,Corresponding Author. . Current postal address: University of Pennsylvania School of Medicine, Department of Psychiatry, 9 Maloney, 3600 Spruce Street, Philadelphia, PA 19104.15. Tel.: 215.615.3183; fax: 215.662.7903
| | - Amrita Ray
- Departments of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California
| | - Ruben C. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Robert Freedman
- Department of Psychiatry, University of Colorado Health Sciences Center, Denver, Colorado
| | - Michael F. Green
- Department of Psychiatry and Biobehavioral Sciences, Geffen School of Medicine at University of California Los Angeles, Los Angeles, California,The Department of Veteran Affairs VISN-22 Mental Illness Research, Education, and Clinical Center; Los Angeles, CA
| | - Tiffany A. Greenwood
- Department of Psychiatry, University of California San Diego, La Jolla, California and VA San Diego Healthcare System; VISN-22 Mental Illness Research, Education, and Clinical Center
| | - Gregory A. Light
- Department of Psychiatry, University of California San Diego, La Jolla, California and VA San Diego Healthcare System; VISN-22 Mental Illness Research, Education, and Clinical Center
| | - Keith H. Nuechterlein
- Department of Psychiatry and Biobehavioral Sciences, Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Ann Olincy
- Department of Psychiatry, University of Colorado Health Sciences Center, Denver, Colorado
| | - Allen D. Radant
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington,The Department of Veteran Affairs VISN-20 Mental Illness Research, Education, and Clinical Center; Seattle, Washington
| | - Larry J. Seidman
- Harvard Institute of Psychiatric Epidemiology and Genetics, Boston, Massachusetts,Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Harvard Medical School Department of Psychiatry, Boston, Massachusetts
| | - Larry J. Siever
- Medical Genetics Research Program and Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, NY,Department of Psychiatry, The Mount Sinai School of Medicine, New York, New York
| | - Jeremy M. Silverman
- Medical Genetics Research Program and Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, NY,Department of Psychiatry, The Mount Sinai School of Medicine, New York, New York
| | - William S. Stone
- Harvard Institute of Psychiatric Epidemiology and Genetics, Boston, Massachusetts,Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Harvard Medical School Department of Psychiatry, Boston, Massachusetts
| | - Catherine Sugar
- The Department of Veteran Affairs VISN-22 Mental Illness Research, Education, and Clinical Center; Los Angeles, CA
| | - Neal R. Swerdlow
- Department of Psychiatry, University of California San Diego, La Jolla, California and VA San Diego Healthcare System; VISN-22 Mental Illness Research, Education, and Clinical Center
| | - Debby W. Tsuang
- Departments of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California
| | - Ming T. Tsuang
- Department of Psychiatry, University of California San Diego, La Jolla, California and VA San Diego Healthcare System; VISN-22 Mental Illness Research, Education, and Clinical Center
| | - Bruce I. Turetsky
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David L. Braff
- Department of Psychiatry, University of California San Diego, La Jolla, California and VA San Diego Healthcare System; VISN-22 Mental Illness Research, Education, and Clinical Center
| | - Laura C. Lazzeroni
- Departments of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California
| | - Raquel E. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania
| |
Collapse
|
24
|
Modelling the emergence of hallucinations: early acquired vulnerabilities, proximal life stressors and maladaptive psychological processes. Soc Psychiatry Psychiatr Epidemiol 2012; 47:1367-80. [PMID: 22045103 DOI: 10.1007/s00127-011-0446-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 10/17/2011] [Indexed: 10/16/2022]
Abstract
BACKGROUND The study aimed to expand upon existing findings on the vulnerability to psychosis by examining synergistic models of hallucination emergence. Hypothesised vulnerability factors were separated into three stages of vulnerability; early acquired and enduring vulnerabilities (heredity, childhood trauma, early cannabis use), proximal life stressors (life hassles) and psychological appraisals/coping (metacognitions/experiential avoidance). METHODS Participants were recruited to a non-clinical sample (N = 133) and a clinical sample of psychosis patients (N = 100). RESULTS Path analyses in the non-clinical sample indicated that experiences of childhood emotional trauma, in combination with subsequent experiences of life hassles, best predicted vulnerability to both hallucinations in general and auditory hallucinations specifically. This pathway was partially mediated by negative metacognitions. The models were then replicated in the clinical sample, with two notable differences: (1) childhood sexual trauma replaced childhood emotional trauma as the best enduring predictor in the clinical model. (2) Experiential avoidance replaced metacognitions as the best cognitive predictor of hallucinations. CONCLUSIONS The study's findings highlighted how vulnerability to hallucinations can occur developmentally across time, with early acquired vulnerability factors, combining additively with more proximal day-to-day factors and cognitive style, to propel a person further towards the formation of hallucinations.
Collapse
|
25
|
Owens SF, Picchioni MM, Ettinger U, McDonald C, Walshe M, Schmechtig A, Murray RM, Rijsdijk F, Toulopoulou T. Prefrontal deviations in function but not volume are putative endophenotypes for schizophrenia. ACTA ACUST UNITED AC 2012; 135:2231-44. [PMID: 22693145 DOI: 10.1093/brain/aws138] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study sought to systematically investigate whether prefrontal cortex grey matter volume reductions are valid endophenotypes for schizophrenia, specifically investigating their presence in unaffected relatives, heritability, genetic overlap with the disorder itself and finally to contrast their performance on these criteria with putative neuropsychological indices of prefrontal functioning. We used a combined twin and family design and examined four prefrontal cortical regions of interest. Superior and inferior regions were significantly smaller in patients. However, the volumes of these same regions were normal in unaffected relatives and therefore, we could confirm that such deficits were not due to familial effects. Volumes of the prefrontal and orbital cortices were, however, moderately heritable, but neither shared a genetic overlap with schizophrenia. Total prefrontal cortical volume reductions shared a significant unique environmental overlap with the disorder, suggesting that the reductions were not familial. In contrast, prefrontal (executive) functioning deficits were present in the unaffected relatives, were moderately heritable and shared a substantial genetic overlap with liability to schizophrenia. These results suggest that the well recognized prefrontal volume reductions are not related to the same familial influences that increase schizophrenia liability and instead may be attributable to illness related biological changes or indeed confounded by illness trajectory, chronicity, medication or substance abuse, or in fact a combination of some or all of them.
Collapse
Affiliation(s)
- Sheena F Owens
- Department of Psychosis Studies, Institute of Psychiatry, Kings College, London, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Landgraf S, Steingen J, Eppert Y, Niedermeyer U, van der Meer E, Krueger F. Temporal information processing in short- and long-term memory of patients with schizophrenia. PLoS One 2011; 6:e26140. [PMID: 22053182 PMCID: PMC3203868 DOI: 10.1371/journal.pone.0026140] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 09/20/2011] [Indexed: 11/19/2022] Open
Abstract
Cognitive deficits of patients with schizophrenia have been largely recognized as core symptoms of the disorder. One neglected factor that contributes to these deficits is the comprehension of time. In the present study, we assessed temporal information processing and manipulation from short- and long-term memory in 34 patients with chronic schizophrenia and 34 matched healthy controls. On the short-term memory temporal-order reconstruction task, an incidental or intentional learning strategy was deployed. Patients showed worse overall performance than healthy controls. The intentional learning strategy led to dissociable performance improvement in both groups. Whereas healthy controls improved on a performance measure (serial organization), patients improved on an error measure (inappropriate semantic clustering) when using the intentional instead of the incidental learning strategy. On the long-term memory script-generation task, routine and non-routine events of everyday activities (e.g., buying groceries) had to be generated in either chronological or inverted temporal order. Patients were slower than controls at generating events in the chronological routine condition only. They also committed more sequencing and boundary errors in the inverted conditions. The number of irrelevant events was higher in patients in the chronological, non-routine condition. These results suggest that patients with schizophrenia imprecisely access temporal information from short- and long-term memory. In short-term memory, processing of temporal information led to a reduction in errors rather than, as was the case in healthy controls, to an improvement in temporal-order recall. When accessing temporal information from long-term memory, patients were slower and committed more sequencing, boundary, and intrusion errors. Together, these results suggest that time information can be accessed and processed only imprecisely by patients who provide evidence for impaired time comprehension. This could contribute to symptomatic cognitive deficits and strategic inefficiency in schizophrenia.
Collapse
Affiliation(s)
- Steffen Landgraf
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
- Inserm-Laboratory of Psychopathology and Mental Diseases, Center for Psychiatry and Neuroscience, U984, Sainte Anne Hospital, Service-Hospitalo Universitaire, Paris, France
| | - Joerg Steingen
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Yvonne Eppert
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | | | - Elke van der Meer
- Department of Psychology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Frank Krueger
- Department of Molecular Neuroscience, Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, United States of America
- Department of Psychology, George Mason University, Fairfax, Virginia, United States of America
- * E-mail:
| |
Collapse
|
27
|
The association of schizophrenia risk D-amino acid oxidase polymorphisms with sensorimotor gating, working memory and personality in healthy males. Neuropsychopharmacology 2011; 36:1677-88. [PMID: 21471957 PMCID: PMC3138651 DOI: 10.1038/npp.2011.49] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
There is evidence supporting a role for the D-amino acid oxidase (DAO) locus in schizophrenia. This study aimed to determine the relationship of five single-nucleotide polymorphisms (SNPs) within the DAO gene identified as promising schizophrenia risk genes (rs4623951, rs2111902, rs3918346, rs3741775, and rs3825251) to acoustic startle, prepulse inhibition (PPI), working memory, and personality dimensions. A highly homogeneous study entry cohort (n = 530) of healthy, young male army conscripts (n = 703) originating from the Greek LOGOS project (Learning On Genetics Of Schizophrenia Spectrum) underwent PPI of the acoustic startle reflex, working memory, and personality assessment. The QTPHASE from the UNPHASED package was used for the association analysis of each SNP or haplotype data, with p-values corrected for multiple testing by running 10,000 permutations of the data. The rs4623951_T-rs3741775_G and rs4623951_T-rs2111902_T diplotypes were associated with reduced PPI and worse performance in working memory tasks and a personality pattern characterized by attenuated anxiety. Median stratification analysis of the risk diplotype group (ie, those individuals homozygous for the T and G alleles (TG+)) showed reduced PPI and working memory performance only in TG+ individuals with high trait anxiety. The rs4623951_T allele, which is the DAO polymorphism most strongly associated with schizophrenia, might tag a haplotype that affects PPI, cognition, and personality traits in general population. Our findings suggest an influence of the gene in the neural substrate mediating sensorimotor gating and working memory, especially when combined with high anxiety and further validate DAO as a candidate gene for schizophrenia and spectrum disorders.
Collapse
|
28
|
van Rijn S, Swaab H, Magnée M, van Engeland H, Kemner C. Psychophysiological markers of vulnerability to psychopathology in men with an extra X chromosome (XXY). PLoS One 2011; 6:e20292. [PMID: 21655260 PMCID: PMC3105055 DOI: 10.1371/journal.pone.0020292] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 04/25/2011] [Indexed: 11/18/2022] Open
Abstract
Studying genetically defined syndromes associated with increased risk for psychopathology may help in understanding neurodevelopmental mechanisms related to risk for psychopathology. Klinefelter syndrome (47,XXY) is one of the most common sex chromosomal aneuploidies (1 in 650 male births) and associated with increased vulnerability for psychopathology, including psychotic symptoms. Yet, it remains unknown whether this increased risk is associated with underlying psychophysiological mechanisms that are typically deficient in individuals with psychotic disorders. The present study assessed three “classic” psychophysiological markers of psychosis in Klinefelter syndrome (KS): smooth pursuit eye movements (SPEM), prepulse inhibition (PPI) and P50 suppression. Fourteen adults with KS and 15 non-clinical adults participated in the study. Data on SPEM (reflecting visuo-motor control) as well as PPI and P50 suppression (reflecting sensory gating) were collected. Dysfunctions in SPEM were observed in individuals with KS, with less smooth pursuit as expressed in lower position gain. Also, reduced sensory gating in individuals with KS was suggested by significantly reduced prepulse inhibition of the startle response (PPI) (effect size 1.6). No abnormalities were found in suppression of the P50 (effect size 0.6). We speculate that impairments in these psychophysiological mechanisms may reflect core brain dysfunctions that may also mediate the described increased vulnerability for psychotic symptoms in KS. Although speculative, such deficit specific, rather than disorder specific, psychophysiological dysfunctions in KS might convey vulnerability to other types of psychopathology as well. As KS already can be diagnosed prenatally, the predictive value of childhood impairments in prepulse inhibition and smooth pursuit for development of psychopathology later in life could be assessed. In sum, studying individuals with KS may prove to be an avenue of research leading to new hypotheses and insights into “at risk” pathways to psychopathology.
Collapse
Affiliation(s)
- Sophie van Rijn
- Clinical Child and Adolescent Studies, Leiden University, Leiden, The Netherlands.
| | | | | | | | | |
Collapse
|
29
|
Goldstone E, Farhall J, Ong B. Synergistic pathways to delusions: enduring vulnerabilities, proximal life stressors and maladaptive psychological coping. Early Interv Psychiatry 2011; 5:122-31. [PMID: 21535423 DOI: 10.1111/j.1751-7893.2011.00264.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM We sought to extend findings on the vulnerability to psychosis by investigating multifactorial pathways to delusions. Risk factors assessed spanned across early acquired vulnerabilities (heredity, childhood trauma, early cannabis use), proximal life stressors (life hassles, methamphetamine use) and psychological coping (experiential avoidance). METHODS Participants were recruited to a non-clinical sample (n = 133) or a clinical sample of psychosis patients (n = 100). RESULTS Path analyses indicated three distinct pathways predicting vulnerability to delusions in the non-clinical sample: (i) childhood emotional trauma combined with subsequent experiences of life hassles; (ii) heredity in combination with experiential avoidance; and (iii) early cannabis use combined with proximal methamphetamine use. The first pathway was partially mediated by experiential avoidance. The model was largely replicated in the clinical sample, with childhood sexual trauma replacing emotional trauma in the model. CONCLUSION The study demonstrated that vulnerability to delusions can be usefully predicted by a synergistic model incorporating early-acquired vulnerability factors, proximal day-to-day factors and cognitive styles.
Collapse
Affiliation(s)
- Eliot Goldstone
- School of Psychological Science, La Trobe University, Bundoora, Victoria, Australia.
| | | | | |
Collapse
|
30
|
Haraldsson HM, Ettinger U, Sigurdsson E. Developments in schizophrenia genetics: from linkage to microchips, deletions and duplications. Nord J Psychiatry 2011; 65:82-8. [PMID: 21271949 DOI: 10.3109/08039488.2011.552734] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND There is strong evidence for significant contributions of genetic factors to the risk of schizophrenia. In the past 10 years, studies employing linkage and association approaches have identified multiple putative schizophrenia risk genes. For most of these, the evidence for association with schizophrenia remains weak and attempts of replication not always successful nor easy to interpret. AIM To give an overview of new developments in genetic research of schizophrenia. METHODS The present literature on schizophrenia genetics was reviewed with special emphasis on new developments such as genome-wide association studies (GWAS), associations of copy number variations (CNVs) with schizophrenia and the role of endophenotypes in genetic research. RESULTS The first GWAS of schizophrenia have identified new putative candidate risk genes and opened avenues for investigating how multiple genes may act in functional biological pathways forming the genetic basis of schizophrenia and other complex diseases. There is growing evidence that rare de novo CNVs as well as some inherited CNVs contribute to the susceptibility to several neuropsychiatric disorders including schizophrenia. Schizophrenia endophenotypes, which possibly better represent biological phenomena than the complex clinical phenotype, are turning out to be helpful for investigating neurobiological pathways of putative risk genes. CONCLUSIONS Recent studies suggest that individual common gene variants make relatively small contributions to risk of schizophrenia but some rare CNVs may be associated with much higher risk when present. Future studies employing new technologies for identifying common and rare risk markers are likely to deepen our understanding of the genetic architecture of schizophrenia.
Collapse
Affiliation(s)
- H Magnus Haraldsson
- Landspitalinn-National University Hospital, Division of Psychiatry, Hringbraut, 101, Reykjavik, Iceland.
| | | | | |
Collapse
|
31
|
Roussos P, Giakoumaki SG, Adamaki E, Bitsios P. The influence of schizophrenia-related neuregulin-1 polymorphisms on sensorimotor gating in healthy males. Biol Psychiatry 2011; 69:479-86. [PMID: 21035784 DOI: 10.1016/j.biopsych.2010.09.009] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/10/2010] [Accepted: 09/06/2010] [Indexed: 02/07/2023]
Abstract
BACKGROUND Neuregulin-1 (NRG1) variations have been shown to modulate schizophrenia candidate endophenotypes related to brain structure and function. The objective of this cross-sectional genetic association study was to determine the relationship of six core single-nucleotide polymorphisms within the NRG1 gene identified as promising schizophrenia risk genes (rs6994992, SNP8NRG221132, SNP8NRG241930, rs3924999, rs2439272 and rs10503929) to prepulse inhibition (PPI) of the acoustic startle reflex, a well validated schizophrenia endophenotype. METHODS PPI was tested in a highly homogeneous study entry cohort (n = 445) of carefully screened healthy, young male army conscripts originating from the Greek LOGOS project (Learning on Genetics of Schizophrenia Spectrum). The QTPHASE from the UNPHASED package was used for the association analysis of each single-nucleotide polymorphisms or haplotype data. RESULTS Reduced PPI, particularly at 75-dB_120-msec and 85-dB_60-msec trials, was related to the SNP8NRG241930 G allele and especially the rs6994992 T allele and rs2439272 C allele. Haplotype analysis followed up by risk versus no-risk groups Analysis of variance confirmed that the rs10503929 and rs3924999 SNPs were also associated with PPI reductions, when combined with rs2439272. CONCLUSIONS We provide solid evidence for a role of NRG1 risk genotype variations in PPI reductions in a large and demographically and genetically highly homogeneous cohort of healthy young males. These results further validate NRG1 as a candidate gene for the schizophrenia and spectrum disorders and improve our understanding of its functional mechanisms within the human brain because they suggest an influence of the gene in the neural substrate mediating sensorimotor gating.
Collapse
Affiliation(s)
- Panos Roussos
- Department of Psychiatry and Behavioral Sciences, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece.
| | | | | | | |
Collapse
|
32
|
Jablensky A, Morar B, Wiltshire S, Carter K, Dragovic M, Badcock JC, Chandler D, Peters K, Kalaydjieva L. Polymorphisms associated with normal memory variation also affect memory impairment in schizophrenia. GENES BRAIN AND BEHAVIOR 2011; 10:410-7. [PMID: 21281445 DOI: 10.1111/j.1601-183x.2011.00679.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Neurocognitive dysfunction is a core feature of schizophrenia with particularly prominent deficits in verbal episodic memory. The molecular basis of this memory impairment is poorly understood and its relatedness to normal variation in memory performance is unclear. In this study, we explore, in a sample of cognitively impaired schizophrenia patients, the role of polymorphisms in seven genes recently reported to modulate episodic memory in normal subjects. Three polymorphisms (GRIN2B rs220599, GRM3 rs2189814 and PRKCA rs8074995) were associated with episodic verbal memory in both control and patients with cognitive deficit, but not in cognitively spared patients or the pooled schizophrenia sample. GRM3 and PRKCA acted in opposite directions in patients compared to controls, possibly reflecting an abnormal brain milieu and/or adverse environmental effects in schizophrenia. The encoded proteins balance glutamate signalling vs. excitotoxicity in complex interactions involving the excitatory amino acid transporter 2 (EAAT2), implicated in the dysfunctional glutamatergic signalling in schizophrenia. Double carrier status of the GRM3 and PRKCA minor alleles was associated with lower memory test scores and with increased risk of schizophrenia. Single nucleotide polymorphism (SNP) rs8074995 lies within the PRKCA region spanned by a rare haplotype associated with schizophrenia in a recent UK study and provides further evidence of PRKCA contribution to memory impairment and susceptibility to schizophrenia. Our study supports the utility of parsing the broad phenotype of schizophrenia into component cognitive endophenotypes that reduce heterogeneity and enable the capture of potentially important genetic associations.
Collapse
Affiliation(s)
- A Jablensky
- Centre for Clinical Research in Neuropsychiatry and School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, Australia.
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Yu S, Li H, Liu W, Zheng L, Ma Y, Chen Q, Chen Y, Yu H, Lu Y, Pan B, Wang W. Alexithymia and personality disorder functioning styles in paranoid schizophrenia. Psychopathology 2011; 44:371-8. [PMID: 21847004 DOI: 10.1159/000325168] [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: 06/03/2010] [Accepted: 01/17/2011] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Personality disorder functioning styles might contribute to the inconclusive findings about alexithymic features in schizophrenia. We therefore studied the relationship between alexithymia and personality styles in paranoid schizophrenia. METHODS We administered the Chinese versions of the Toronto Alexithymia Scale (TAS-20), the Parker Personality Measure (PERM), the Positive and Negative Syndrome Scale as well as the Hamilton Anxiety and Depression Scales to 60 paranoid schizophrenia patients and 60 healthy control subjects. RESULTS Patients scored significantly higher on the Positive and Negative Syndrome Scale, TAS 'difficulty identifying feelings' and 'difficulty describing feelings', Hamilton Depression Scale and most PERM scales. In healthy subjects, difficulty identifying feelings predicted the PERM 'dependent' style, and the Hamilton Anxiety Scale predicted difficulty identifying feelings and difficulty describing feelings. In patients, difficulty identifying feelings nonspecifically predicted all the PERM scales; by contrast, the PERM 'antisocial' style predicted difficulty identifying feelings, the 'avoidant' style predicted difficulty describing feelings, and the 'histrionic' and 'paranoid (-)' styles predicted 'externally oriented thinking'. CONCLUSIONS Personality disorder functioning styles - instead of anxiety, depression, psychotic symptoms or disease duration - were specifically associated with alexithymia scales in our patients, which sheds light on a cognitive-personological substrate in paranoid schizophrenia on the one hand, and calls for a longitudinal design to discover how premorbid or postacute residual personality styles contribute to the sluggish disorder on the other.
Collapse
Affiliation(s)
- Shaohua Yu
- Department of Psychiatry, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Chkonia E, Roinishvili M, Makhatadze N, Tsverava L, Stroux A, Neumann K, Herzog MH, Brand A. The shine-through masking paradigm is a potential endophenotype of schizophrenia. PLoS One 2010; 5:e14268. [PMID: 21151559 PMCID: PMC3000331 DOI: 10.1371/journal.pone.0014268] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 11/19/2010] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND To understand the genetics of schizophrenia, a hunt for so-called intermediate phenotypes or endophenotypes is ongoing. Visual masking has been proposed to be such an endophenotype. However, no systematic study has been conducted yet to prove this claim. Here, we present the first study showing that masking meets the most important criteria for an endophenotype. METHODOLOGY/PRINCIPAL FINDINGS We tested 62 schizophrenic patients, 39 non-affected first-degree relatives, and 38 healthy controls in the shine-through masking paradigm and, in addition, in the Continuous Performance Test (CPT) and the Wisconsin Card Sorting Test (WCST). Most importantly, masking performance of relatives was significantly in between the one of patients and controls in the shine-through paradigm. Moreover, deficits were stable throughout one year. Using receiver operating characteristics (ROC) methods, we show that the shine-through paradigm distinguishes with high sensitivity and specificity between schizophrenic patients, first-order relatives and healthy controls. CONCLUSIONS/SIGNIFICANCE The shine-through paradigm is a potential endophenotype.
Collapse
Affiliation(s)
- Eka Chkonia
- Department of Psychiatry, Tbilisi State Medical University, Tbilisi, Georgia.
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Knaapila A, Silventoinen K, Broms U, Rose RJ, Perola M, Kaprio J, Tuorila HM. Food neophobia in young adults: genetic architecture and relation to personality, pleasantness and use frequency of foods, and body mass index--a twin study. Behav Genet 2010; 41:512-21. [PMID: 20953688 DOI: 10.1007/s10519-010-9403-8] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 09/28/2010] [Indexed: 11/28/2022]
Abstract
Food neophobia has been studied extensively in children, but its causal origins and relationship to eating behavior in adults are not well understood. We studied genetic and environmental effects on variation in food neophobia, measured using the Food Neophobia Scale, and explored associations between food neophobia and personality, pleasantness and use frequency of food groups, and body mass index in young adult twins (N = 1175, aged 20-25 years, 54.7% women). In women, additive genetic effects (heritability) accounted for 61% of variation in food neophobia, whereas in men, shared environmental effects explained 45% of the variation. Food neophobia negatively correlated with the personality trait Openness, corrected for the structural overlap (r = -0.23), and in women, these two traits had a genetic correlation (r (g) = -0.39). In addition, food neophobia negatively correlated with pleasantness and use frequency of fruits and vegetables and of fish and with mean pleasantness of foods. Once evolutionarily important, food neophobia should at present be considered in nutrition counseling as a possible barrier to a balanced diet.
Collapse
Affiliation(s)
- Antti Knaapila
- Monell Chemical Senses Center, Philadelphia, PA 19119, USA.
| | | | | | | | | | | | | |
Collapse
|
36
|
Magaud E, Kebir O, Gut A, Willard D, Chauchot F, Olie JP, Kazes M, Krebs MO. Altered semantic but not phonological verbal fluency in young help-seeking individuals with ultra high risk of psychosis. Schizophr Res 2010; 123:53-8. [PMID: 20605416 DOI: 10.1016/j.schres.2010.05.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 04/02/2010] [Accepted: 05/08/2010] [Indexed: 11/17/2022]
Abstract
Some of the cognitive impairments of schizophrenia are already detectable before the onset of the disease, and could help to identify individuals at higher risk of psychosis. In patients with schizophrenia, semantic verbal fluency (VF) is more impaired than phonological fluency. We investigated whether the same profile is present in young patients at Ultra High Risk of psychosis (UHR). One hundred and fifty six young patients (15-30y.o.) consecutively seeking help at our specialized youth mental health center with no definite psychiatric diagnoses were recruited and assessed with the CAARMS. Individuals meeting the criteria for UHR were compared to the remaining patients considered as Help Seeker Controls (HSCo). UHR individuals had a lower mean total semantic fluency score than HSCo. This effect was significant for each semantic category ('animals' and 'fruits'). By contrast, there were no differences in phonological fluency scores between UHR and HSCo either in the total score or when each letter ('P' and 'R') was considered separately. Semantic but not phonological VF differentiated UHR individuals from non-psychotic help-seeking young adults. These results suggest that semantic deficits are present during the prodromal phase, prior to clinical expression of full-blown psychosis, and suggest that prodromes could be associated with alteration in temporal brain areas.
Collapse
|
37
|
Heritability of acoustic startle magnitude, prepulse inhibition, and startle latency in schizophrenia and control families. Psychiatry Res 2010; 178:236-43. [PMID: 20483176 PMCID: PMC2902662 DOI: 10.1016/j.psychres.2009.11.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 10/29/2009] [Accepted: 11/09/2009] [Indexed: 11/20/2022]
Abstract
Prepulse inhibition (PPI) is an acoustic startle paradigm that has been used as an operational measure of sensorimotor gating. Many patients with schizophrenia have impaired PPI, and several lines of evidence suggest that PPI may represent a heritable endophenotype in this disease. We examined startle magnitude and latencies in 40 schizophrenia patients, 58 first-degree relatives of these patients, and 100 healthy controls. After removing low-startlers, we investigated PPI and startle habituation in 34 schizophrenia patients, 43 relatives, and 86 control subjects. Heritability analyses were conducted using a variance-component approach. We found significant heritability of 45% for PPI at the 60-ms interval and 67% for startle magnitude. Onset latency heritability estimates ranged between 39% and 90% across trial types, and those for peak latency ranged from 29% to 68%. Heritability of startle habituation trended toward significance at 31%. We did not detect differences between controls and either schizophrenia patients or their family members for PPI, startle magnitude, or habituation. Startle latencies were generally longer in schizophrenia patients than controls. The heritability findings give impetus to applying genetic analyses to PPI variables, and suggest that startle latency may also be a useful measure in the study of potential endophenotypes for schizophrenia.
Collapse
|
38
|
Bertisch H, Li D, Hoptman MJ, DeLisi LE. Heritability estimates for cognitive factors and brain white matter integrity as markers of schizophrenia. Am J Med Genet B Neuropsychiatr Genet 2010; 153B:885-94. [PMID: 20052692 PMCID: PMC3446203 DOI: 10.1002/ajmg.b.31054] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent genetics research focusing on schizophrenia has led to candidate cognitive and neuroimaging variables as intermediate phenotypes or "endophenotype" markers for the illness. Among other stringent criteria, to be an endophenotype, a marker must demonstrate heritability. In an effort to explore the validity of a selection of cognitive and neuroimaging endophenotypes, the present study was designed to determine estimates of their heritability. One hundred fourteen subjects, including 27 with schizophrenia and 39 unaffected relatives from 23 multiplex schizophrenia families, participated in a comprehensive neuropsychological test battery and structural brain imaging with diffusion tensor imaging (DTI). Variables were selected if they previously have been demonstrated to show differences between people with schizophrenia and normal controls. Significant evidence of heritability was confirmed for overall cognitive function ("g"), as well as expressive and receptive language, verbal and visual memory, processing speed and cognitive inhibition. In addition, significant heritability estimates were determined for specific regions in the frontal, central, parietal, and occipital areas. These results suggest that the variables chosen may be useful endophenotypes for genetic and early detection studies, although further work with larger cohorts should be conducted to show that deficits in these functions and structures also segregate with schizophrenia within families and thus fully satisfy the definition of an endophenotype. In addition, other cognitive and neuroimaging variables that were not studied here may be candidates for schizophrenia endophenotypes.
Collapse
Affiliation(s)
- Hilary Bertisch
- Department of Psychiatry, New York University School of Medicine, New York, New York 10016, USA.
| | - Dawei Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Matthew J. Hoptman
- Department of Psychiatry, New York University School of Medicine, New York, New York,Division of Clinical Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York
| | - Lynn E. DeLisi
- Department of Psychiatry, New York University School of Medicine, New York, New York,Department of Psychiatry, Harvard Medical School, Boston VA Brockton Health Services System, Brockton, Massachusetts
| |
Collapse
|
39
|
Sommer IEC, Daalman K, Rietkerk T, Diederen KM, Bakker S, Wijkstra J, Boks MPM. Healthy individuals with auditory verbal hallucinations; who are they? Psychiatric assessments of a selected sample of 103 subjects. Schizophr Bull 2010; 36:633-41. [PMID: 18849293 PMCID: PMC2879692 DOI: 10.1093/schbul/sbn130] [Citation(s) in RCA: 199] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Epidemiological studies suggest that auditory verbal hallucinations (AVH) occur in approximately 10%-15% of the general population, of whom only a small proportion has a clinically relevant psychotic disorder. It is unclear whether these hallucinations occur as an isolated phenomenon or if AVH in nonclinical individuals are part of a more general susceptibility to schizophrenia. For this study, 103 healthy individuals with frequent AVH were compared with 60 controls matched for sex, age, and education. All participants were examined by a psychiatrist using standardized diagnostic interviews and questionnaires. The individuals with AVH did not have clinically defined delusions, disorganization, or negative or catatonic symptoms, nor did they meet criteria for cluster A personality disorder. However, their global level of functioning was lower than in the controls and there was a pronounced increase on all subclusters of the Schizotypal Personality Questionnaire (SPQ) and the Peters Delusion Inventory, indicating a general increased schizotypal and delusional tendency in the hallucinating subjects. History of childhood trauma and family history of axis I disorders were also more prevalent in these individuals. We showed that higher SPQ scores, lower education, and higher family loading for psychiatric disorders, but not presence of AVH, were associated with lower global functioning. Our data suggest that AVH in otherwise healthy individuals are not an isolated phenomenon but part of a general vulnerability for schizophrenia.
Collapse
Affiliation(s)
- Iris EC Sommer
- Neuroscience Division University Medical Center Utrecht, B01.206, Rudolf Magnus School for Neuroscience, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands,To whom correspondence should be addressed; tel: +31-88-7556370, fax: +31-88-5555443, e-mail:
| | - Kirstin Daalman
- Neuroscience Division University Medical Center Utrecht, B01.206, Rudolf Magnus School for Neuroscience, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Thomas Rietkerk
- Neuroscience Division University Medical Center Utrecht, B01.206, Rudolf Magnus School for Neuroscience, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Kelly M. Diederen
- Neuroscience Division University Medical Center Utrecht, B01.206, Rudolf Magnus School for Neuroscience, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Steven Bakker
- Neuroscience Division University Medical Center Utrecht, B01.206, Rudolf Magnus School for Neuroscience, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Jaap Wijkstra
- Neuroscience Division University Medical Center Utrecht, B01.206, Rudolf Magnus School for Neuroscience, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Marco P. M. Boks
- Neuroscience Division University Medical Center Utrecht, B01.206, Rudolf Magnus School for Neuroscience, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| |
Collapse
|
40
|
Elvevåg B, Foltz PW, Rosenstein M, DeLisi LE. An automated method to analyze language use in patients with schizophrenia and their first-degree relatives. JOURNAL OF NEUROLINGUISTICS 2010; 23:270-284. [PMID: 20383310 PMCID: PMC2850213 DOI: 10.1016/j.jneuroling.2009.05.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Communication disturbances are prevalent in schizophrenia, and since it is a heritable illness these are likely present - albeit in a muted form - in the relatives of patients. Given the time-consuming, and often subjective nature of discourse analysis, these deviances are frequently not assayed in large scale studies. Recent work in computational linguistics and statistical-based semantic analysis has shown the potential and power of automated analysis of communication. We present an automated and objective approach to modeling discourse that detects very subtle deviations between probands, their first-degree relatives and unrelated healthy controls. Although these findings should be regarded as preliminary due to the limitations of the data at our disposal, we present a brief analysis of the models that best differentiate these groups in order to illustrate the utility of the method for future explorations of how language components are differentially affected by familial and illness related issues.
Collapse
Affiliation(s)
- Brita Elvevåg
- Clinical Brain Disorders Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room 4S235, MSC 1379, Bethesda MD 20892
| | - Peter W. Foltz
- Pearson Knowledge Technologies and University of Colorado, Institute for Cognitive Science, 4940 Pearl East Circle, Suite 200, Boulder, CO 80301
| | - Mark Rosenstein
- Pearson Knowledge Technologies, 4940 Pearl East Circle, Suite 200, Boulder, CO 80301
| | - Lynn E. DeLisi
- Department of Psychiatry, New York University Langone Medical Center and The Nathan S. Kline Institute for Psychiatric Research, 650 First Avenue, New York, NY 10016
| |
Collapse
|
41
|
Heritability of Trail Making Test performance in multiplex schizophrenia families: implications for the search for an endophenotype. Eur Arch Psychiatry Clin Neurosci 2009; 259:475-81. [PMID: 19399358 DOI: 10.1007/s00406-009-0012-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Accepted: 04/07/2009] [Indexed: 01/08/2023]
Abstract
The impairment of the Trail Making Test (TMT) performance as a measure of executive function deficits has been found both in patients with schizophrenia and in their unaffected first-degree relatives, suggesting that it might be considered as a familial vulnerability marker, but its heritability estimates are not well known. This study investigated the genetic heritability of impairments in TMT performance using a sample of 80 schizophrenia patients, 145 unaffected first-degree relatives and 127 healthy controls from families with multiple members with schizophrenia. Consistent with previous reports in the literature, relatives performed in between healthy controls and schizophrenia patients. Based on these results, a variance component-analysis provided small, but significant additive heritability estimates for performance indices relating performance in TMT-version A to TMT-version B. These results showed that this significant but small evidence of heritability on the one hand suggests an association with genetic predisposition to schizophrenia, but that TMT performance is also associated with epigenetic or environmental factors.
Collapse
|
42
|
Abstract
Kraepelin proposed dementia praecox and manic-depressive illness as the two major psychotic disorders. This paradigm is still prevalent, but observations of overlapping boundaries between bipolar disorder and schizophrenia challenge this dichotomy. However, the concept of schizophrenia has been radically altered from the original Kraepelinian proposal. We defend the two psychoses positions, but suggest two flaws in the heuristic application: (1) overlapping features, such as psychotic symptoms, are not decisive in differential diagnosis; and (2) each disorder is a syndrome, not a disease entity. An alternative paradigm based on domains of pathology is more powerful for studies of etiology, pathophysiology, and therapeutic discovery.
Collapse
|
43
|
Genetic overlap among intelligence and other candidate endophenotypes for schizophrenia. Biol Psychiatry 2009; 65:527-34. [PMID: 19013556 DOI: 10.1016/j.biopsych.2008.09.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Revised: 09/23/2008] [Accepted: 09/23/2008] [Indexed: 01/13/2023]
Abstract
BACKGROUND A strategy to improve genetic studies of schizophrenia involves the use of endophenotypes. Information on overlapping genetic contributions among endophenotypes may provide additional power, reveal biological pathways, and have practical implications for genetic research. Several cognitive endophenotypes, including intelligence, are likely to be modulated by overlapping genetic influences. METHODS We quantified potential genetic and environmental correlations among endophenotypes for schizophrenia, including sensorimotor gating, openness, verbal fluency, early visual perception, spatial working memory, and intelligence, using variance component models in 35 patients and 145 relatives from 25 multigenerational Dutch families multiply affected with schizophrenia. RESULTS Significant correlations were found between spatial working memory and intelligence (.45), verbal fluency and intelligence (.36), verbal fluency and spatial working memory (.20), and early visual perception and spatial working memory (.19). A strong genetic correlation (.75) accounted for 76% of the variance shared between spatial working memory and intelligence. Significant environmental correlations were found between verbal fluency and openness (.50) and between verbal fluency and spatial working memory (.58). Sensorimotor gating and openness showed few genetic or environmental correlations with other endophenotypes. CONCLUSIONS Our results suggest that intelligence strongly overlaps genetically with a known cognitive endophenotype for schizophrenia. Intelligence may thus be a promising endophenotype for genetic research in schizophrenia, even though the underlying genetic mechanism may still be complex. In contrast, sensorimotor gating and openness appear to represent separate genetic entities with simpler inheritance patterns and may therefore augment the detection of separate genetic pathways contributing to schizophrenia.
Collapse
|