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Wang B, Otten LJ, Schulze K, Afrah H, Varney L, Cotic M, Saadullah Khani N, Linden JF, Kuchenbaecker K, McQuillin A, Hall MH, Bramon E. Is auditory processing measured by the N100 an endophenotype for psychosis? A family study and a meta-analysis. Psychol Med 2024; 54:1559-1572. [PMID: 37997703 DOI: 10.1017/s0033291723003409] [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: 11/25/2023]
Abstract
BACKGROUND The N100, an early auditory event-related potential, has been found to be altered in patients with psychosis. However, it is unclear if the N100 is a psychosis endophenotype that is also altered in the relatives of patients. METHODS We conducted a family study using the auditory oddball paradigm to compare the N100 amplitude and latency across 243 patients with psychosis, 86 unaffected relatives, and 194 controls. We then conducted a systematic review and a random-effects meta-analysis pooling our results and 14 previously published family studies. We compared data from a total of 999 patients, 1192 relatives, and 1253 controls in order to investigate the evidence and degree of N100 differences. RESULTS In our family study, patients showed reduced N100 amplitudes and prolonged N100 latencies compared to controls, but no significant differences were found between unaffected relatives and controls. The meta-analysis revealed a significant reduction of the N100 amplitude and delay of the N100 latency in both patients with psychosis (standardized mean difference [s.m.d.] = -0.48 for N100 amplitude and s.m.d. = 0.43 for N100 latency) and their relatives (s.m.d. = - 0.19 for N100 amplitude and s.m.d. = 0.33 for N100 latency). However, only the N100 latency changes in relatives remained significant when excluding studies with affected relatives. CONCLUSIONS N100 changes, especially prolonged N100 latencies, are present in both patients with psychosis and their relatives, making the N100 a promising endophenotype for psychosis. Such changes in the N100 may reflect changes in early auditory processing underlying the etiology of psychosis.
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Affiliation(s)
- Baihan Wang
- Division of Psychiatry, University College London, London, UK
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Leun J Otten
- Institute of Cognitive Neuroscience, University College London, London, UK
| | - Katja Schulze
- South London and Maudsley NHS Foundation Trust, London, UK
| | - Hana Afrah
- Division of Psychiatry, University College London, London, UK
| | - Lauren Varney
- Division of Psychiatry, University College London, London, UK
| | - Marius Cotic
- Division of Psychiatry, University College London, London, UK
- Department of Genetics & Genomic Medicine, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | | | - Jennifer F Linden
- Ear Institute, University College London, London, UK
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Karoline Kuchenbaecker
- Division of Psychiatry, University College London, London, UK
- Division of Biosciences, UCL Genetics Institute, University College London, London, UK
| | | | - Mei-Hua Hall
- Psychosis Neurobiology Laboratory, Harvard Medical School, McLean Hospital, Belmont, MA, USA
| | - Elvira Bramon
- Division of Psychiatry, University College London, London, UK
- Institute of Cognitive Neuroscience, University College London, London, UK
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An Integrative Analysis of Identified Schizophrenia-Associated Brain Cell Types and Gene Expression Changes. Int J Mol Sci 2022; 23:ijms231911581. [PMID: 36232882 PMCID: PMC9569514 DOI: 10.3390/ijms231911581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/21/2022] [Accepted: 09/27/2022] [Indexed: 11/23/2022] Open
Abstract
Schizophrenia (SCZ) is a severe mental disorder that may result in hallucinations, delusions, and extremely disordered thinking. How each cell type in the brain contributes to SCZ occurrence is still unclear. Here, we leveraged the human dorsolateral prefrontal cortex bulk RNA-seq data, then used the RNA-seq deconvolution algorithm CIBERSORTx to generate SCZ brain single-cell RNA-seq data for a comprehensive analysis to understand SCZ-associated brain cell types and gene expression changes. Firstly, we observed that the proportions of brain cell types in SCZ differed from normal samples. Among these cell types, astrocyte, pericyte, and PAX6 cells were found to have a higher proportion in SCZ patients (astrocyte: SCZ = 0.163, control = 0.145, P.adj = 4.9 × 10-4, effect size = 0.478; pericyte: SCZ = 0.057, control = 0.066, P.adj = 1.1 × 10-4, effect size = 0.519; PAX6: SCZ = 0.014, control = 0.011, P.adj = 0.014, effect size = 0.377), while the L5/6_IT_CAR3 cells and LAMP5 cells are the exact opposite (L5/6_IT_Car3: SCZ = 0.102, control = 0.108, P.adj = 0.016, effect size = 0.369; LAMP5: SCZ = 0.057, control = 0.066, P.adj = 2.2 × 10-6, effect size = 0.617). Next, we investigated gene expression in cell types and functional pathways in SCZ. We observed chemical synaptic transmission dysregulation in two types of GABAergic neurons (PVALB and LAMP5), and immune reaction involvement in GABAergic neurons (SST) and non-neuronal cell types (endothelial and oligodendrocyte). Furthermore, we observed that some differential expression genes from bulk RNA-seq displayed cell-type-specific abnormalities in the expression of molecules in SCZ. Finally, the cell types with the SCZ-related transcriptomic changes could be considered to belong to the same module since we observed two major similar coordinated transcriptomic changes across these cell types. Together, our results offer novel insights into cellular heterogeneity and the molecular mechanisms underlying SCZ.
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Neurophysiology in psychosis: The quest for disease biomarkers. Transl Psychiatry 2022; 12:100. [PMID: 35277479 PMCID: PMC8917164 DOI: 10.1038/s41398-022-01860-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 02/14/2022] [Accepted: 02/18/2022] [Indexed: 01/11/2023] Open
Abstract
Psychotic disorders affect 3% of the population at some stage in life, are a leading cause of disability, and impose a great economic burden on society. Major breakthroughs in the genetics of psychosis have not yet been matched by an understanding of its neurobiology. Biomarkers of perception and cognition obtained through non-invasive neurophysiological tools, especially EEG, offer a unique opportunity to gain mechanistic insights. Techniques for measuring neurophysiological markers are inexpensive and ubiquitous, thus having the potential as an accessible tool for patient stratification towards early treatments leading to better outcomes. In this paper, we review the literature on neurophysiological markers for psychosis and their relevant disease mechanisms, mainly covering event-related potentials including P50/N100 sensory gating, mismatch negativity, and the N100 and P300 waveforms. While several neurophysiological deficits are well established in patients with psychosis, more research is needed to study neurophysiological markers in their unaffected relatives and individuals at clinical high risk. We need to harness EEG to investigate markers of disease risk as key steps to elucidate the aetiology of psychosis and facilitate earlier detection and treatment.
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4
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Prolonged P300 Latency in Antipsychotic-Free Subjects with At-Risk Mental States Who Later Developed Schizophrenia. J Pers Med 2021; 11:jpm11050327. [PMID: 33919276 PMCID: PMC8143351 DOI: 10.3390/jpm11050327] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/16/2021] [Accepted: 04/18/2021] [Indexed: 12/17/2022] Open
Abstract
We measured P300, an event-related potential, in subjects with at-risk mental states (ARMS) and aimed to determine whether P300 parameter can predict progression to overt schizophrenia. Thirty-three subjects with ARMS, 39 with schizophrenia, and 28 healthy controls participated in the study. All subjects were antipsychotic-free. Subjects with ARMS were followed-up for more than two years. Cognitive function was measured by the Brief assessment of Cognition in Schizophrenia (BACS) and Schizophrenia Cognition Rating Scale (SCoRS), while the modified Global Assessment of Functioning (mGAF) was used to assess global function. Patients with schizophrenia showed smaller P300 amplitudes and prolonged latency at Pz compared to those of healthy controls and subjects with ARMS. During the follow-up period, eight out of 33 subjects with ARMS developed overt psychosis (ARMS-P) while 25 did not (ARMS-NP). P300 latency of ARMS-P was significantly longer than that of ARMS-NP. At baseline, ARMS-P elicited worse cognitive functions, as measured by the BACS and SCoRS compared to ARMS-NP. We also detected a significant relationship between P300 amplitudes and mGAF scores in ARMS subjects. Our results suggest the usefulness of prolonged P300 latency and cognitive impairment as a predictive marker of later development of schizophrenia in vulnerable individuals.
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5
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Bramon E, Dempster E, Frangou S, McDonald C, Schoenberg P, MacCabe JH, Walshe M, Sham P, Collier D, Murray RM. Is there an association between the COMT gene and P300 endophenotypes? Eur Psychiatry 2020; 21:70-3. [PMID: 16414251 DOI: 10.1016/j.eurpsy.2005.11.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AbstractP300 wave anomalies correlate with genetic risk for schizophrenia and constitute a plausible endophenotype for the disease. The COMT gene is thought to influence cognitive performance and to be a susceptibility gene for schizophrenia. Unlike two previous studies, we found no significant influence of the COMT gene on P300 amplitude or latency in 189 individuals examined. The well-supported role of the COMT gene both in dopamine catabolism as well as in prefrontal cognition makes a strong theoretical case for the influence of COMT Val158Met polymorphism on P300 endophenotypes. However, the available neurophysiologic evidence suggests that any such association, if present, must be very subtle.
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Affiliation(s)
- E Bramon
- Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK.
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6
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Lavoie S, Polari AR, Goldstone S, Nelson B, McGorry PD. Staging model in psychiatry: Review of the evolution of electroencephalography abnormalities in major psychiatric disorders. Early Interv Psychiatry 2019; 13:1319-1328. [PMID: 30688016 DOI: 10.1111/eip.12792] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 10/03/2018] [Accepted: 12/29/2018] [Indexed: 12/29/2022]
Abstract
AIM Clinical staging in psychiatry aims to classify patients according to the severity of their symptoms, from stage 0 (increased risk, asymptomatic) to stage 4 (severe illness), enabling adapted treatment at each stage of the illness. The staging model would gain specificity if one or more quantifiable biological markers could be identified. Several biomarkers reflecting possible causal mechanisms and/or consequences of the pathophysiology are candidates for integration into the clinical staging model of psychiatric illnesses. METHODS This review covers the evolution (from stage 0 to stage 4) of the most important brain functioning impairments as measured with electroencephalography (EEG), in psychosis spectrum and in severe mood disorders. RESULTS The present review of the literature demonstrates that it is currently not possible to draw any conclusion with regard to the state or trait character of any of the EEG impairments in both major depressive disorder and bipolar disorder. As for schizophrenia, the most promising markers of the stage of the illness are the pitch mismatch negativity as well as the p300 event-related potentials, as these components seem to deteriorate with increasing severity of the illness. CONCLUSIONS Given the complexity of major psychiatric disorders, and that not a single impairment can be observed in all patients, future research should most likely consider combinations of markers in the quest for a better identification of the stages of the psychiatric illnesses.
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Affiliation(s)
- Suzie Lavoie
- Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Victoria, Australia.,Centre for Youth Mental Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Andrea R Polari
- Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Victoria, Australia.,Orygen Youth Health, Melbourne Health, Melbourne, Victoria, Australia
| | - Sherilyn Goldstone
- Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Victoria, Australia.,Centre for Youth Mental Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Barnaby Nelson
- Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Victoria, Australia.,Centre for Youth Mental Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Patrick D McGorry
- Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Victoria, Australia.,Centre for Youth Mental Health, The University of Melbourne, Melbourne, Victoria, Australia
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7
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Blakey R, Ranlund S, Zartaloudi E, Cahn W, Calafato S, Colizzi M, Crespo-Facorro B, Daniel C, Díez-Revuelta Á, Di Forti M, Iyegbe C, Jablensky A, Jones R, Hall MH, Kahn R, Kalaydjieva L, Kravariti E, Lin K, McDonald C, McIntosh AM, Picchioni M, Powell J, Presman A, Rujescu D, Schulze K, Shaikh M, Thygesen JH, Toulopoulou T, Van Haren N, Van Os J, Walshe M, Murray RM, Bramon E. Associations between psychosis endophenotypes across brain functional, structural, and cognitive domains. Psychol Med 2018; 48:1325-1340. [PMID: 29094675 PMCID: PMC6516747 DOI: 10.1017/s0033291717002860] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND A range of endophenotypes characterise psychosis, however there has been limited work understanding if and how they are inter-related. METHODS This multi-centre study includes 8754 participants: 2212 people with a psychotic disorder, 1487 unaffected relatives of probands, and 5055 healthy controls. We investigated cognition [digit span (N = 3127), block design (N = 5491), and the Rey Auditory Verbal Learning Test (N = 3543)], electrophysiology [P300 amplitude and latency (N = 1102)], and neuroanatomy [lateral ventricular volume (N = 1721)]. We used linear regression to assess the interrelationships between endophenotypes. RESULTS The P300 amplitude and latency were not associated (regression coef. -0.06, 95% CI -0.12 to 0.01, p = 0.060), and P300 amplitude was positively associated with block design (coef. 0.19, 95% CI 0.10-0.28, p 0.38). All the cognitive endophenotypes were associated with each other in the expected directions (all p < 0.001). Lastly, the relationships between pairs of endophenotypes were consistent in all three participant groups, differing for some of the cognitive pairings only in the strengths of the relationships. CONCLUSIONS The P300 amplitude and latency are independent endophenotypes; the former indexing spatial visualisation and working memory, and the latter is hypothesised to index basic processing speed. Individuals with psychotic illnesses, their unaffected relatives, and healthy controls all show similar patterns of associations between endophenotypes, endorsing the theory of a continuum of psychosis liability across the population.
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Affiliation(s)
- R. Blakey
- Division of Psychiatry, University College London, London, UK
| | - S. Ranlund
- Division of Psychiatry, University College London, London, UK
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - E. Zartaloudi
- Division of Psychiatry, University College London, London, UK
| | - W. Cahn
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - S. Calafato
- Division of Psychiatry, University College London, London, UK
| | - M. Colizzi
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - B. Crespo-Facorro
- CIBERSAM, Centro Investigación Biomédica en Red Salud Mental, Madrid, Spain
- Department of Psychiatry, University Hospital Marqués de Valdecilla, School of Medicine, University of Cantabria–IDIVAL, Santander, Spain
| | - C. Daniel
- Division of Psychiatry, University College London, London, UK
| | - Á. Díez-Revuelta
- Division of Psychiatry, University College London, London, UK
- Laboratory of Cognitive and Computational Neuroscience – Centre for Biomedical Technology (CTB), Complutense University and Technical University of Madrid, Madrid, Spain
| | - M. Di Forti
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | | | - C. Iyegbe
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - A. Jablensky
- Centre for Clinical Research in Neuropsychiatry, The University of Western Australia, Perth, Western Australia, Australia
| | - R. Jones
- Division of Psychiatry, University College London, London, UK
| | - M.-H. Hall
- Psychology Research Laboratory, Harvard Medical School, McLean Hospital, Belmont, MA, USA
| | - R. Kahn
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - L. Kalaydjieva
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - E. Kravariti
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - K. Lin
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - C. McDonald
- Department of Psychiatry, Clinical Science Institute, National University of Ireland Galway, Ireland
| | - A. M. McIntosh
- Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, UK
| | | | - M. Picchioni
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - J. Powell
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - A. Presman
- Division of Psychiatry, University College London, London, UK
| | - D. Rujescu
- Department of Psychiatry, Ludwig-Maximilians University of Munich, Munich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, University of Halle Wittenberg, Halle, Germany
| | - K. Schulze
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - M. Shaikh
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- North East London Foundation Trust, London, UK
| | - J. H. Thygesen
- Division of Psychiatry, University College London, London, UK
| | - T. Toulopoulou
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- Department of Psychology, Bilkent University, Main Campus, Bilkent, Ankara, Turkey
- Department of Psychology, the University of Hong Kong, Pokfulam Rd, Hong Kong SAR, China
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, The Hong Kong Jockey Club Building for Interdisciplinary Research, Hong Kong SAR, China
| | - N. Van Haren
- Department of Psychiatry, Brain Centre Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - J. Van Os
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- Department of Psychiatry and Psychology, Maastricht University Medical Centre, EURON, Maastricht, The Netherlands
| | - M. Walshe
- Division of Psychiatry, University College London, London, UK
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | | | - R. M. Murray
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
| | - E. Bramon
- Division of Psychiatry, University College London, London, UK
- Institute of Psychiatry Psychology and Neuroscience at King’s College London and South London and Maudsley NHS Foundation Trust, London, UK
- Institute of Cognitive Neuroscience, University College London, London, UK
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Abstract
BackgroundNeurobiological studies of the early course of psychoses, such as schizophrenia, allow investigation of pathophysiology without the confounds of illness chronicity and treatment.AimsTo review the recent literature on the biology of the early course of psychoses.MethodWe carried out a critical appraisal of the recent findings in the neurobiology of early psychoses, using structural, functional and neurochemical imaging techniques.ResultsBrain structural alterations are present early in the illness and may predate symptom onset. Some changes, notably those in frontal and temporal lobes, can progress during the early phases of the illness. Functional and neurochemical brain abnormalities can also be seen in the premorbid and the early phases of the illness. Some, although not all, changes can be trait-like whereas some others might progress during the early years.ConclusionsA better understanding of such changes, especially during the critical periods of the prodrome, around the transition to the psychotic phase and during the early phases of the illness is crucial for continued research into preventive intervention strategies.
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Affiliation(s)
- Matcheri S Keshavan
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, UCH 9B, 4201 St Antoine Boulevard, Detroit, MI, USA.
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9
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Ranlund S, Calafato S, Thygesen JH, Lin K, Cahn W, Crespo‐Facorro B, de Zwarte SM, Díez Á, Di Forti M, Iyegbe C, Jablensky A, Jones R, Hall M, Kahn R, Kalaydjieva L, Kravariti E, McDonald C, McIntosh AM, McQuillin A, Picchioni M, Prata DP, Rujescu D, Schulze K, Shaikh M, Toulopoulou T, van Haren N, van Os J, Vassos E, Walshe M, Lewis C, Murray RM, Powell J, Bramon E. A polygenic risk score analysis of psychosis endophenotypes across brain functional, structural, and cognitive domains. Am J Med Genet B Neuropsychiatr Genet 2018; 177:21-34. [PMID: 28851104 PMCID: PMC5763362 DOI: 10.1002/ajmg.b.32581] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 07/24/2017] [Indexed: 12/26/2022]
Abstract
This large multi-center study investigates the relationships between genetic risk for schizophrenia and bipolar disorder, and multi-modal endophenotypes for psychosis. The sample included 4,242 individuals; 1,087 patients with psychosis, 822 unaffected first-degree relatives of patients, and 2,333 controls. Endophenotypes included the P300 event-related potential (N = 515), lateral ventricular volume (N = 798), and the cognitive measures block design (N = 3,089), digit span (N = 1,437), and the Ray Auditory Verbal Learning Task (N = 2,406). Data were collected across 11 sites in Europe and Australia; all genotyping and genetic analyses were done at the same laboratory in the United Kingdom. We calculated polygenic risk scores for schizophrenia and bipolar disorder separately, and used linear regression to test whether polygenic scores influenced the endophenotypes. Results showed that higher polygenic scores for schizophrenia were associated with poorer performance on the block design task and explained 0.2% (p = 0.009) of the variance. Associations in the same direction were found for bipolar disorder scores, but this was not statistically significant at the 1% level (p = 0.02). The schizophrenia score explained 0.4% of variance in lateral ventricular volumes, the largest across all phenotypes examined, although this was not significant (p = 0.063). None of the remaining associations reached significance after correction for multiple testing (with alpha at 1%). These results indicate that common genetic variants associated with schizophrenia predict performance in spatial visualization, providing additional evidence that this measure is an endophenotype for the disorder with shared genetic risk variants. The use of endophenotypes such as this will help to characterize the effects of common genetic variation in psychosis.
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Affiliation(s)
- Siri Ranlund
- Division of PsychiatryUniversity College LondonLondonUK
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | | | | | - Kuang Lin
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Nuffield Department of Population HealthUniversity of OxfordOxfordUK
| | - Wiepke Cahn
- Department of Psychiatry, Brain Centre Rudolf MagnusUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Benedicto Crespo‐Facorro
- CIBERSAMCentro Investigación Biomédica en Red Salud MentalMadridSpain
- Department of Psychiatry, University Hospital Marqués de Valdecilla, School of MedicineUniversity of Cantabria–IDIVALSantanderSpain
| | - Sonja M.C. de Zwarte
- Department of Psychiatry, Brain Centre Rudolf MagnusUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Álvaro Díez
- Division of PsychiatryUniversity College LondonLondonUK
- Laboratory of Cognitive and Computational Neuroscience—Centre for Biomedical Technology (CTB)Complutense University and Technical University of MadridMadridSpain
| | - Marta Di Forti
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | | | - Conrad Iyegbe
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Assen Jablensky
- Centre for Clinical Research in NeuropsychiatryThe University of Western AustraliaPerth, Western AustraliaAustralia
| | - Rebecca Jones
- Division of PsychiatryUniversity College LondonLondonUK
| | - Mei‐Hua Hall
- Psychosis Neurobiology Laboratory, Harvard Medical SchoolMcLean HospitalBelmontMassachusetts
| | - Rene Kahn
- Department of Psychiatry, Brain Centre Rudolf MagnusUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Luba Kalaydjieva
- Harry Perkins Institute of Medical Research and Centre for Medical ResearchThe University of Western AustraliaPerthAustralia
| | - Eugenia Kravariti
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Colm McDonald
- The Centre for Neuroimaging & Cognitive Genomics (NICOG) and NCBES Galway Neuroscience CentreNational University of Ireland GalwayGalwayIreland
| | - Andrew M. McIntosh
- Division of Psychiatry, University of EdinburghRoyal Edinburgh HospitalEdinburghUK
- Centre for Cognitive Ageing and Cognitive EpidemiologyUniversity of EdinburghEdinburghUK
| | | | | | - Marco Picchioni
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Diana P. Prata
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Faculdade de Medicina, Instituto de Medicina MolecularUniversidade de LisboaPortugal
| | - Dan Rujescu
- Department of PsychiatryLudwig‐Maximilians University of MunichMunichGermany
- Department of Psychiatry, Psychotherapy and PsychosomaticsUniversity of Halle WittenbergHalleGermany
| | - Katja Schulze
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Madiha Shaikh
- North East London Foundation TrustLondonUK
- Research Department of Clinical, Educational and Health PsychologyUniversity College LondonLondonUK
| | - Timothea Toulopoulou
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Department of Psychology, Bilkent UniversityMain CampusBilkent, AnkaraTurkey
- Department of PsychologyThe University of Hong Kong, Pokfulam RdHong Kong SARChina
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong KongThe Hong Kong Jockey Club Building for Interdisciplinary ResearchHong Kong SARChina
| | - Neeltje van Haren
- Department of Psychiatry, Brain Centre Rudolf MagnusUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Jim van Os
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Department of Psychiatry and Psychology, Maastricht University Medical CentreEURONMaastrichtThe Netherlands
| | - Evangelos Vassos
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Muriel Walshe
- Division of PsychiatryUniversity College LondonLondonUK
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | | | - Cathryn Lewis
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Robin M. Murray
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - John Powell
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
| | - Elvira Bramon
- Division of PsychiatryUniversity College LondonLondonUK
- Institute of Psychiatry Psychology and Neuroscience at King's College London and South LondonMaudsley NHS Foundation TrustLondonUK
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
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Earls HA, Curran T, Mittal V. A Meta-analytic Review of Auditory Event-Related Potential Components as Endophenotypes for Schizophrenia: Perspectives From First-Degree Relatives. Schizophr Bull 2016; 42:1504-1516. [PMID: 27217271 PMCID: PMC5049529 DOI: 10.1093/schbul/sbw047] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
INTRODUCTION As endophenotypes bridge the gap between genetics and phenotypic disease expression, identifying reliable markers is important for fostering understanding of pathophysiology. The present aim was to conduct current meta-analyses of 3 key auditory event-related potential (ERP) components that have been held as potential endophenotypes for schizophrenia: P50, P300 amplitude and latency, and mismatch negativity (MMN), reflective of sensory gating, attention and classification speed, and perceptual discrimination ability, respectively. In order to assess endophenotype viability, these components were examined in unaffected relatives of patients with schizophrenia and healthy controls. METHODS Effect sizes (ES) were examined between relatives and controls for P50 suppression (10 studies, n = 360 relatives, 473 controls), P300 amplitude (20 studies, n = 868 relatives, 961 controls), P300 latency (17 studies, n = 674 relatives, 792 controls), and MMN (11 studies, n = 377 relatives, 552 controls). RESULTS Reliable differences in P50 suppression (ES = 0.86, P < .001), P300 amplitude (ES = -0.52, P < .001), and P300 latency (ES = 0.44, P < .05) were found between unaffected relatives and controls. A trend was found between relatives and controls for MMN (ES = 0.21, P = 0.06), and the use of extraneous channels was found to be a significant moderator (P = 0.01). When MMN was analyzed using frontocentral channel Fz, a significant difference was found (ES = 0.26, P < 0.01). DISCUSSION The results indicate that P50 suppression, P300 amplitude and P300 latency, and MMN may serve as viable endophenotypes for schizophrenia.
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Affiliation(s)
- Holly A. Earls
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO
| | - Tim Curran
- Department of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO
| | - Vijay Mittal
- Department of Psychology, Northwestern University, Evanston, IL
- Department of Psychiatry, Northwestern University, Chicago, IL
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11
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Devrim-Üçok M, Keskin-Ergen Y, Üçok A. Lack of progressive reduction in P3 amplitude after the first-episode of schizophrenia: A 6-year follow-up study. Psychiatry Res 2016; 243:303-11. [PMID: 27428084 DOI: 10.1016/j.psychres.2016.02.065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 01/11/2016] [Accepted: 02/27/2016] [Indexed: 12/13/2022]
Abstract
P3 event-related potential may track the course of neurophysiological pathology in schizophrenia. Reduction in the amplitude of the auditory P3 is a widely replicated finding, already present at the first psychotic episode, in schizophrenia. Whether a progressive deficit is present in auditory P3 in schizophrenia over the course of illness is yet to be clarified. Previous longitudinal studies did not report any change in P3 over time in schizophrenia. However, these studies have been inconclusive, because of their relatively short follow-up periods, lack of follow-up data on controls, and assessment of patients already at the chronic stages of schizophrenia. Auditory P3 potentials, elicited by an oddball paradigm, were assessed in 14 patients with first-episode schizophrenia and 22 healthy controls at baseline and at the 6-year follow-up. P3 amplitudes were smaller in patients with first-episode schizophrenia than in controls. Importantly, over the 6-year interval, the P3 amplitudes were reduced in controls, but they did not change in patients. The lack of P3 reduction over time in patients with schizophrenia might be explained by the maximal reduction in P3 already at baseline or by the alleviation of P3 reduction over time.
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Affiliation(s)
- Müge Devrim-Üçok
- (a)Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, 34093 Çapa, Istanbul, Turkey.
| | - Yasemin Keskin-Ergen
- (a)Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, 34093 Çapa, Istanbul, Turkey
| | - Alp Üçok
- Department of Psychiatry, Istanbul Faculty of Medicine, Istanbul University, 34093 Çapa, Istanbul, Turkey
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12
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Dejanović M, Ivetić V, Nestorović V, Erić M, Stanojević Z, Leštarević S. The role of P300 event-related potentials in the cognitive recovery after the stroke. Acta Neurol Belg 2015; 115:589-95. [PMID: 25578637 DOI: 10.1007/s13760-015-0428-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 01/05/2015] [Indexed: 11/25/2022]
Abstract
The aim of this study was to elucidate the effects of an ischemic stroke on the amplitude and latency of the P300 wave and evaluate their changes over a prospective 1-year follow-up period. We recorded the P300 wave using an auditory oddball paradigm in 60 consecutive brain infarct patients at baseline (i.e., within 4 weeks after the stroke), after 3 months, after 12 months and in 30 healthy control subjects. The P300 latencies in stroke patients were significantly longer and the P300 amplitudes were significantly smaller than those of the control group. The latency of P300 showed a highly significant average improvement 12 months after the stroke compared to the baseline. There was no significant change observed for the P300 amplitude during the same period. The P3 latency is initially more increased in the patients with hemispheric brain infarction but shows a better recovery compared to the patients with brainstem infarction. Also, the results of the P300 latency of patients with the left-sided lesions was significantly longer compared to the patients with right-sided lesions on the beginning of the study but not 3 and 12 months after the stroke. The results of our study show the importance of P300 event-related potentials in the detection and follow-up of cognitive changes after ischemic stroke.
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Affiliation(s)
- Mirjana Dejanović
- Department of Physiology, Faculty of Medicine, University of Priština, Anri Dinana bb, 38 220, Kosovska Mitrovica, Serbia.
| | - Vesna Ivetić
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | - Vojkan Nestorović
- Department of Physiology, Faculty of Medicine, University of Priština, Anri Dinana bb, 38 220, Kosovska Mitrovica, Serbia
| | - Mirela Erić
- Department of Anatomy, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | - Zorica Stanojević
- Department of Pharmacology, Faculty of Medicine, University of Priština, Kosovska Mitrovica, Serbia
| | - Snežana Leštarević
- Department of Histology, Faculty of Medicine, University of Priština, Kosovska Mitrovica, Serbia
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13
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Siekmeier PJ. Computational modeling of psychiatric illnesses via well-defined neurophysiological and neurocognitive biomarkers. Neurosci Biobehav Rev 2015; 57:365-80. [DOI: 10.1016/j.neubiorev.2015.09.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 09/23/2015] [Accepted: 09/27/2015] [Indexed: 12/22/2022]
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14
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Featherstone RE, McMullen MF, Ward KR, Bang J, Xiao J, Siegel SJ. EEG biomarkers of target engagement, therapeutic effect, and disease process. Ann N Y Acad Sci 2015; 1344:12-26. [DOI: 10.1111/nyas.12745] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Robert E. Featherstone
- Translational Neuroscience Program; Department of Psychiatry; University of Pennsylvania; Philadelphia Pennsylvania
| | - Mary F. McMullen
- Translational Neuroscience Program; Department of Psychiatry; University of Pennsylvania; Philadelphia Pennsylvania
| | - Katelyn R. Ward
- Translational Neuroscience Program; Department of Psychiatry; University of Pennsylvania; Philadelphia Pennsylvania
| | - Jakyung Bang
- Translational Neuroscience Program; Department of Psychiatry; University of Pennsylvania; Philadelphia Pennsylvania
| | - Jane Xiao
- Translational Neuroscience Program; Department of Psychiatry; University of Pennsylvania; Philadelphia Pennsylvania
| | - Steven J. Siegel
- Translational Neuroscience Program; Department of Psychiatry; University of Pennsylvania; Philadelphia Pennsylvania
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15
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del Re EC, Spencer KM, Oribe N, Mesholam-Gately RI, Goldstein J, Shenton ME, Petryshen T, Seidman LJ, McCarley RW, Niznikiewicz MA. Clinical high risk and first episode schizophrenia: auditory event-related potentials. Psychiatry Res 2015; 231:126-33. [PMID: 25557063 PMCID: PMC4314407 DOI: 10.1016/j.pscychresns.2014.11.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 11/07/2014] [Accepted: 11/19/2014] [Indexed: 01/15/2023]
Abstract
The clinical high risk (CHR) period is a phase denoting a risk for overt psychosis during which subacute symptoms often appear, and cognitive functions may deteriorate. To compare biological indices during this phase with those during first episode schizophrenia, we cross-sectionally examined sex- and age-matched clinical high risk (CHR, n=21), first episode schizophrenia patients (FESZ, n=20) and matched healthy controls (HC, n=25) on oddball and novelty paradigms and assessed the N100, P200, P3a and P3b as indices of perceptual, attentional and working memory processes. To our knowledge, this is the only such comparison using all of these event-related potentials (ERPs) in two paradigms. We hypothesized that the ERPs would differentiate between the three groups and allow prediction of a diagnostic group. The majority of ERPs were significantly affected in CHR and FESZ compared with controls, with similar effect sizes. Nonetheless, in logistic regression, only the P3a and N100 distinguished CHR and FESZ from healthy controls, suggesting that ERPs not associated with an overt task might be more sensitive to prediction of group membership.
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Affiliation(s)
- Elisabetta C del Re
- VA Boston Healthcare System, Brockton, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA; Psychiatry Neuroimaging Laboratory, Department of Psychiatry and Department of Radiology, Brigham and Women׳s Hospital, Harvard Medical School, Boston, MA, USA.
| | - Kevin M Spencer
- VA Boston Healthcare System, Brockton, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Naoya Oribe
- VA Boston Healthcare System, Brockton, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA; Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Raquelle I Mesholam-Gately
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA; Harvard Medical School, Massachusetts Mental Health Center Division of Public Psychiatry, Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Jill Goldstein
- Harvard Medical School, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA; Brigham and Women׳s Hospital, Connors Center for Women׳s Health and Gender Biology, Boston, MA, USA; Departments of Psychiatry and Medicine, Harvard Medical School, Boston, MA, USA
| | - Martha E Shenton
- VA Boston Healthcare System, Brockton, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA; Psychiatry Neuroimaging Laboratory, Department of Psychiatry and Department of Radiology, Brigham and Women׳s Hospital, Harvard Medical School, Boston, MA, USA
| | - Tracey Petryshen
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA; Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research and Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - Larry J Seidman
- Harvard Medical School, Massachusetts Mental Health Center Division of Public Psychiatry, Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA; Harvard Medical School, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - Robert W McCarley
- VA Boston Healthcare System, Brockton, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Margaret A Niznikiewicz
- VA Boston Healthcare System, Brockton, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA
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16
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Peters RM, Gjini K, Templin TN, Boutros NN. A statistical methodology to improve accuracy in differentiating schizophrenia patients from healthy controls. Psychiatry Res 2014; 216:333-9. [PMID: 24613007 DOI: 10.1016/j.psychres.2014.02.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 02/06/2014] [Accepted: 02/09/2014] [Indexed: 11/29/2022]
Abstract
We present a methodology to statistically discriminate among univariate and multivariate indices to improve accuracy in differentiating schizophrenia patients from healthy controls. Electroencephalogram data from 71 subjects (37 controls/34 patients) were analyzed. Data included P300 event-related response amplitudes and latencies as well as amplitudes and sensory gating indices derived from the P50, N100, and P200 auditory-evoked responses resulting in 20 indices analyzed. Receiver operator characteristic (ROC) curve analyses identified significant univariate indices; these underwent principal component analysis (PCA). Logistic regression of PCA components created a multivariate composite used in the final ROC. Eleven univariate ROCs were significant with area under the curve (AUC) >0.50. PCA of these indices resulted in a three-factor solution accounting for 76.96% of the variance. The first factor was defined primarily by P200 and P300 amplitudes, the second by P50 ratio and difference scores, and the third by P300 latency. ROC analysis using the logistic regression composite resulted in an AUC of 0.793 (0.06), p<0.001 (CI=0.685-0.901). A composite score of 0.456 had a sensitivity of 0.829 (correctly identifying schizophrenia patients) and a specificity of 0.703 (correctly identifying healthy controls). Results demonstrated the usefulness of combined statistical techniques in creating a multivariate composite that improves diagnostic accuracy.
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Affiliation(s)
| | - Klevest Gjini
- Seton Brain and Spine Institute, Austin, TX 78701, USA
| | - Thomas N Templin
- College of Nursing, Wayne State University, Detroit, MI 48202, USA
| | - Nash N Boutros
- Department of Psychiatry and Neuroscience University of Missouri Kansas City, MO 64110, USA
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17
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Boutros NN, Mucci A, Diwadkar V, Tandon R. Negative Symptoms in Schizophrenia. ACTA ACUST UNITED AC 2014; 8:28-35B. [DOI: 10.3371/csrp.bomu.012513] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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18
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The impact of stroke on cognitive processing — A prospective event-related potential study. J Neurol Sci 2014; 339:157-63. [DOI: 10.1016/j.jns.2014.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 02/06/2014] [Accepted: 02/10/2014] [Indexed: 11/22/2022]
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19
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Shaikh M, Hall MH, Schulze K, Dutt A, Li K, Williams I, Walshe M, Constante M, Broome M, Picchioni M, Toulopoulou T, Collier D, Stahl D, Rijsdijk F, Powell J, Murray RM, Arranz M, Bramon E. Effect of DISC1 on the P300 waveform in psychosis. Schizophr Bull 2013; 39:161-7. [PMID: 21878470 PMCID: PMC3523903 DOI: 10.1093/schbul/sbr101] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
INTRODUCTION Abnormalities in the neurophysiological measures P300 amplitude and latency constitute endophenotypes for psychosis. Disrupted-in-Schizophrenia-1 (DISC1) has been proposed as a promising susceptibility gene for schizophrenia, and a previous study has suggested that it is associated with P300 deficits in schizophrenia. METHODS We examined the role of variation in DISC1 polymorphisms on the P300 endophenotype in a large sample of patients with schizophrenia or psychotic bipolar disorder (n = 149), their unaffected relatives (n = 130), and unrelated healthy controls (n = 208) using linear regression and haplotype analysis. RESULTS Significant associations between P300 amplitude and latency and DISC1 polymorphisms/haplotypes were found. Those homozygous for the A allele of single-nucleotide polymorphism (SNP) rs821597 displayed significantly reduced P300 amplitudes in comparison with homozygous for the G allele (P = .009) and the heterozygous group (P = .018). Haplotype analysis showed a significant association for DISC1 haplotypes (rs3738401|rs6675281|rs821597|rs821616|rs967244|rs980989) and P300 latency. Haplotype GCGTCG and ACGTTT were associated with shorter latencies. DISCUSSION The P300 waveform appears to be modulated by variation in individual SNPs and haplotypes of DISC1. Because DISC1 is involved in neurodevelopment, one hypothesis is that disruption in neural connectivity impairs cognitive processes illustrated by P300 deficits observed in this sample.
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Affiliation(s)
- Madiha Shaikh
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College Londonand The South London and Maudsley NHS Foundation Trust, London SE58AF, UK.
| | - Mei-Hua Hall
- Psychology Research Laboratory, Harvard Medical School, McLean Hospital, Belmont, MA
| | - Katja Schulze
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Anirban Dutt
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Kuang Li
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Ian Williams
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Muriel Walshe
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Miguel Constante
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Matthew Broome
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Marco Picchioni
- St Andrew’s Academic Centre, Institute of Psychiatry, King’s College London, Northampton, UK
| | - Timothea Toulopoulou
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - David Collier
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK,Medical Research Council, Social, Genetic and Developmental Psychiatry Research Centre, Institute of Psychiatry, King's College, London, UK
| | - Daniel Stahl
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Fruhling Rijsdijk
- Medical Research Council, Social, Genetic and Developmental Psychiatry Research Centre, Institute of Psychiatry, King's College, London, UK
| | - John Powell
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Robin M. Murray
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Maria Arranz
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
| | - Elvira Bramon
- Department of Psychosis Studies, NIHR Biomedical Research Centre for Mental Health at the Institute of Psychiatry, King's College London and The South London and Maudsley NHS Foundation Trust, London SE5 8AF, UK
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Simple viewing tests can detect eye movement abnormalities that distinguish schizophrenia cases from controls with exceptional accuracy. Biol Psychiatry 2012; 72:716-24. [PMID: 22621999 DOI: 10.1016/j.biopsych.2012.04.019] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Revised: 04/02/2012] [Accepted: 04/03/2012] [Indexed: 12/31/2022]
Abstract
BACKGROUND We have investigated which eye-movement tests alone and combined can best discriminate schizophrenia cases from control subjects and their predictive validity. METHODS A training set of 88 schizophrenia cases and 88 controls had a range of eye movements recorded; the predictive validity of the tests was then examined on eye-movement data from 34 9-month retest cases and controls, and from 36 novel schizophrenia cases and 52 control subjects. Eye movements were recorded during smooth pursuit, fixation stability, and free-viewing tasks. Group differences on performance measures were examined by univariate and multivariate analyses. Model fitting was used to compare regression, boosted tree, and probabilistic neural network approaches. RESULTS As a group, schizophrenia cases differed from control subjects on almost all eye-movement tests, including horizontal and Lissajous pursuit, visual scanpath, and fixation stability; fixation dispersal during free viewing was the best single discriminator. Effects were stable over time, and independent of sex, medication, or cigarette smoking. A boosted tree model achieved perfect separation of the 88 training cases from 88 control subjects; its predictive validity on retest assessments and novel cases and control subjects was 87.8%. However, when we examined the whole data set of 298 assessments, a cross-validated probabilistic neural network model was superior and could discriminate all cases from controls with near perfect accuracy at 98.3%. CONCLUSIONS Simple viewing patterns can detect eye-movement abnormalities that can discriminate schizophrenia cases from control subjects with exceptional accuracy.
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Abstract
Schizophrenia is an illness where the clinical signs and symptoms, course, and cognitive characteristics are well described. Successful pharmacological treatments do exist, even though they are likely palliative. However, this broad knowledge base has not yet led to the identification of its pathophysiology or etiology The risk factors for schizophrenia are most prominently genetic and scientists anticipate that contributions from the new genetic information in the human genome will help progress towards discovering a disease mechanism. Brain-imaging techniques have opened up the schizophrenic brain for direct inquiries, in terms of structure, neurochemisiry, and function. New proposals for diagnosis include grouping schizophrenia together with schizophrenia-related personality disorders into the same disease entity, and calling this schizophrenia spectrum disorder. New hypotheses of pathophysiology do not overlook dopamine as playing a major role, but do emphasize the participation of integrative neural systems in the expression of the illness and of the limbic system in generating symptoms. Critical observations for future discovery are likely to arise from molecular genetics, combined with hypothesis-generating experiments using brain imaging and human postmortem tissue.
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Affiliation(s)
- C A Tamminga
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Md, USA
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Abstract
Genetic epidemiology has provided consistent evidence that schizophrenia has a genetic component It is now clear that this genetic component is complex and polygenic, with several genes interacting in epistasis. Although molecular studies have failed to identify any DNA variant that clearly contributes to vulnerability to schizophrenia, several regions have been implicated by linkage studies. To overcome the difficulties in the search for schizophrenia genes, it is necessary (i) to use methods of analysis that are appropriate for complex multifactorial disorders; (ii) to gather large enough clinical samples; and (iii) in the absence of genetic validity of the diagnostic classification currently used, to apply new strategies in order to better define the affected phenotypes. For this purpose, we describe here two strategies: (i) the candidate symptom approach, which concerns affected subjects and uses proband characteristics as the affected phenotype, such as age at onset, severity, and negative/positive symptoms; and (ii) the endophenotypic approach, which concerns unaffected relatives and has already provided positive findings with phenotypes, such as P50 inhibitory gating or eye-movement dysfunctions.
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Affiliation(s)
- M Leboyer
- Service de psychiatrie adulte, CHU Albert Chenevier et Henri Mondor, Université Paris XII, Créteil, France
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Beedie SA, Benson PJ, Giegling I, Rujescu D, St Clair DM. Smooth pursuit and visual scanpaths: Independence of two candidate oculomotor risk markers for schizophrenia. World J Biol Psychiatry 2012; 13:200-10. [PMID: 21545243 DOI: 10.3109/15622975.2011.566628] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES Smooth pursuit and visual scanpath deficits are candidate trait markers for schizophrenia. It is not clear whether eye tracking dysfunction (ETD) and atypical scanpath behaviour are the product of the same underlying neurobiological processes. We have examined co-occurrence of ETD and scanpath disturbance in individuals with schizophrenia and healthy volunteers. METHODS Eye movements of individuals with schizophrenia (N = 96) and non-clinical age-matched comparison participants (N = 100) were recorded using non-invasive infrared oculography during smooth pursuit in both predictable (horizontal sinusoid) and less predictable (Lissajous sinusoid) conditions and a free viewing scanpath task. RESULTS Individuals with schizophrenia demonstrated scanning deficits in both tasks. There was no association between performance measures of smooth pursuit and scene scanpaths in patient or control groups. Odds ratios comparing the likelihood of scanpath dysfunction when ETD was present, and the likelihood of finding scanpath dysfunction when ETD was absent were not significant in patients or controls in either pursuit variant, suggesting that ETD and scanpath dysfunction are independent anomalies in schizophrenia. CONCLUSION ETD and scanpath disturbance appear to reflect independent oculomotor or neurocognitive deficits in schizophrenia. Each task may confer unique information about the pathophysiology of psychosis.
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Affiliation(s)
- Sara A Beedie
- School of Psychology, College of Life Sciences & Medicine, William Guild Building, University of Aberdeen, King's College, Aberdeen, UK.
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Simons CJ, Sambeth A, Krabbendam L, Pfeifer S, van Os J, Riedel WJ. Auditory P300 and N100 components as intermediate phenotypes for psychotic disorder: Familial liability and reliability. Clin Neurophysiol 2011; 122:1984-90. [DOI: 10.1016/j.clinph.2011.02.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 02/21/2011] [Accepted: 02/28/2011] [Indexed: 11/26/2022]
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Dutt A, Ganguly T, Shaikh M, Walshe M, Schulze K, Marshall N, Constante M, McDonald C, Murray RM, Allin MPG, Bramon E. Association between hippocampal volume and P300 event related potential in psychosis: support for the Kraepelinian divide. Neuroimage 2011; 59:997-1003. [PMID: 21924362 DOI: 10.1016/j.neuroimage.2011.08.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 08/08/2011] [Accepted: 08/21/2011] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Abnormalities of the P300 event related potential (ERP) and of hippocampal structure are observed in individuals with psychotic disorders and their unaffected relatives. The understanding and clinical management of psychotic disorders are largely based on the descriptive Kraepelinian distinction between 'dementia praecox' and 'manic depressive psychosis', and not dependant on any well demarcated biological underpinnings. The hippocampus is postulated to be one of the main P300 generators, yet it remains unknown whether hippocampal volume decrements are associated with P300 deficits in psychosis, and whether any association is shared across non-affective and affective psychotic disorders. METHODS 228 subjects from the Maudsley Family Psychosis Study comprising 55 patients with non-affective psychosis, 23 patients with psychotic bipolar disorder, 98 unaffected relatives, and 52 unrelated controls contributed structural MRI and ERP data. To study the relationship between hippocampal volume and P300 ERP, a seemingly unrelated regression methodology was used, accounting for whole brain volumes, clinical groups, age and gender in the analysis. RESULTS An association between left hippocampal volume and P300 latency in the combined sample comprising non-affective and affective psychotic patients, their relatives and controls was observed. There was an inverse relationship between brain structure and function in that prolongation of P300 latencies was associated with smaller left hippocampal volumes. On subdividing the sample based on Kraepelinian dichotomy, this association remained significant only for the non-affective psychosis group, comprising patients and their unaffected relatives. CONCLUSIONS Based on our findings, P300 latency, a measure of the speed of neural transmission, appears to be related to the size of the left hippocampus in schizophrenia, but not in psychotic bipolar disorder. It seems that underlying neuro-biological characteristics could help in unravelling the traditional Kraepelinian differentiation between the two major psychoses. The specificity of this brain structure-function association for schizophrenia opens the scope for further research using integration of multimodal biological data for objective categorisation of psychosis.
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Affiliation(s)
- Anirban Dutt
- NIHR Biomedical Research Centre, Institute of Psychiatry (King's College London)/South London and Maudsley NHS Foundation Trust, London, UK.
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Foxe JJ, Yeap S, Snyder AC, Kelly SP, Thakore JH, Molholm S. The N1 auditory evoked potential component as an endophenotype for schizophrenia: high-density electrical mapping in clinically unaffected first-degree relatives, first-episode, and chronic schizophrenia patients. Eur Arch Psychiatry Clin Neurosci 2011; 261:331-9. [PMID: 21153832 PMCID: PMC3119740 DOI: 10.1007/s00406-010-0176-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Accepted: 11/23/2010] [Indexed: 12/19/2022]
Abstract
The N1 component of the auditory evoked potential (AEP) is a robust and easily recorded metric of auditory sensory-perceptual processing. In patients with schizophrenia, a diminution in the amplitude of this component is a near-ubiquitous finding. A pair of recent studies has also shown this N1 deficit in first-degree relatives of schizophrenia probands, suggesting that the deficit may be linked to the underlying genetic risk of the disease rather than to the disease state itself. However, in both these studies, a significant proportion of the relatives had other psychiatric conditions. As such, although the N1 deficit represents an intriguing candidate endophenotype for schizophrenia, it remains to be shown whether it is present in a group of clinically unaffected first-degree relatives. In addition to testing first-degree relatives, we also sought to replicate the N1 deficit in a group of first-episode patients and in a group of chronic schizophrenia probands. Subject groups consisted of 35 patients with schizophrenia, 30 unaffected first-degree relatives, 13 first-episode patients, and 22 healthy controls. Subjects sat in a dimly lit room and listened to a series of simple 1,000-Hz tones, indicating with a button press whenever they heard a deviant tone (1,500 Hz; 17% probability), while the AEP was recorded from 72 scalp electrodes. Both chronic and first-episode patients showed clear N1 amplitude decrements relative to healthy control subjects. Crucially, unaffected first-degree relatives also showed a clear N1 deficit. This study provides further support for the proposal that the auditory N1 deficit in schizophrenia is linked to the underlying genetic risk of developing this disorder. In light of recent studies, these results point to the N1 deficit as an endophenotypic marker for schizophrenia. The potential future utility of this metric as one element of a multivariate endophenotype is discussed.
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Affiliation(s)
- John J Foxe
- The Cognitive Neurophysiology Laboratory, Nathan S. Kline Institute for Psychiatric Research, Program in Cognitive Neuroscience and Schizophrenia, Orangeburg, NY 10962, USA.
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Chen YC, Lu YC, Lung FW. Confirmatory Factor Analysis in Neurophysiological and Neuropsychological Dimensions of Schizophrenia. Int J Neurosci 2011; 121:528-35. [DOI: 10.3109/00207454.2011.582239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Huang MW, Chou FHC, Lo PY, Cheng KS. A comparative study on long-term evoked auditory and visual potential responses between Schizophrenic patients and normal subjects. BMC Psychiatry 2011; 11:74. [PMID: 21542917 PMCID: PMC3113739 DOI: 10.1186/1471-244x-11-74] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 05/04/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The electrical signals measuring method is recommended to examine the relationship between neuronal activities and measure with the event related potentials (ERPs) during an auditory and a visual oddball paradigm between schizophrenic patients and normal subjects. The aim of this study is to discriminate the activation changes of different stimulations evoked by auditory and visual ERPs between schizophrenic patients and normal subjects. METHODS Forty-three schizophrenic patients were selected as experimental group patients, and 40 healthy subjects with no medical history of any kind of psychiatric diseases, neurological diseases, or drug abuse, were recruited as a control group. Auditory and visual ERPs were studied with an oddball paradigm. All the data were analyzed by SPSS statistical software version 10.0. RESULTS In the comparative study of auditory and visual ERPs between the schizophrenic and healthy patients, P300 amplitude at Fz, Cz, and Pz and N100, N200, and P200 latencies at Fz, Cz, and Pz were shown significantly different. The cognitive processing reflected by the auditory and the visual P300 latency to rare target stimuli was probably an indicator of the cognitive function in schizophrenic patients. CONCLUSIONS This study shows the methodology of application of auditory and visual oddball paradigm identifies task-relevant sources of activity and allows separation of regions that have different response properties. Our study indicates that there may be slowness of automatic cognitive processing and controlled cognitive processing of visual ERPs compared to auditory ERPs in schizophrenic patients. The activation changes of visual evoked potentials are more regionally specific than auditory evoked potentials.
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Affiliation(s)
- Min-Wei Huang
- Institute of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan,Department of Psychiatry, Chiayi Branch, Taichung Veterans General Hospital, Chia-Yi 600, Taiwan
| | | | - Pei-Yu Lo
- Institute of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Kuo-Sheng Cheng
- Institute of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan
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Beedie SA, St. Clair DM, Benson PJ. Atypical scanpaths in schizophrenia: evidence of a trait- or state-dependent phenomenon? J Psychiatry Neurosci 2011; 36:150-64. [PMID: 21223647 PMCID: PMC3080511 DOI: 10.1503/jpn.090169] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The development of trait markers of schizophrenia would represent an important advance in understanding the genetic architecture of the disease. To date, no candidate markers have satisfied all of the trait marker criteria, and many are not specific to the schizophrenia spectrum. Abnormalities in visual scanpaths are frequently reported in patients with schizophrenia and are emerging as a novel candidate for a schizophrenia biomarker. Here we review the suitability of scanpath measures as a target for trait marker research in schizophrenia. Papers reporting scanpath patterns in patients with schizophrenia were identified by PubMed and Google Scholar searches and by scanning reference lists in relevant articles. Search terms included "schizophrenia," "psychosis," "scanpath," "scan path," "fixation," "saccade" and "eye movement." Scanpath abnormalities afford impressive sensitivity and specificity and appear largely independent of psychotropic medications. Scanpaths may demonstrate some fluctuation with symptomatology and may be useful in illuminating illness state or subtypes. However, there is evidence that viewing behaviours remain atypical regardless of symptom remission and may be present in unaffected relatives of individuals with schizophrenia. This research is in its early stages, and further investigation regarding patterns of inheritance is required. Our findings support scanpath measures as a favourable topic for further investigation as a trait marker.
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Affiliation(s)
- Sara A. Beedie
- Correspondence to: Dr. S.A. Beedie, School of Psychology, College of Life Sciences and Medicine, University of Aberdeen, William Guild Bldg., King’s College, Aberdeen, Scotland, AB24 3FX;
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Lee SY, Namkoong K, Cho HH, Song DH, An SK. Reduced visual P300 amplitudes in individuals at ultra-high risk for psychosis and first-episode schizophrenia. Neurosci Lett 2010; 486:156-60. [DOI: 10.1016/j.neulet.2010.09.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 08/31/2010] [Accepted: 09/14/2010] [Indexed: 11/30/2022]
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Preuss UW, Zetzsche T, Pogarell O, Mulert C, Frodl T, Müller D, Schmidt G, Born C, Reiser M, Möller HJ, Hegerl U, Meisenzahl EM. Anterior cingulum volumetry, auditory P300 in schizophrenia with negative symptoms. Psychiatry Res 2010; 183:133-9. [PMID: 20630714 DOI: 10.1016/j.pscychresns.2010.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 04/19/2010] [Accepted: 05/16/2010] [Indexed: 10/19/2022]
Abstract
The anterior cingulate cortex (ACC) is located at the rostum of the corpus callosum and involved in both cognitive and emotional brain processes. It has been suggested to be involved in P300 event-related potential generation. A large sample of schizophrenia inpatients and controls was examined in order to assess the potential relationship between ACC volumes and P300 characteristics in patients with more pronounced negative symptoms. In 50 male schizophrenia patients and 50 matched controls, auditory P300 and structural magnetic resonance imaging volume measurements of the ACC were obtained. Patients' negative symptoms were assessed using the PANSS (Positive and Negative Syndrome Scale). Volumetry of ACC subregions revealed a volume reduction in patients with schizophrenia compared with controls in right hemispheric rostral ACC subregions that were most pronounced in more negative schizophrenia patients. There was a positive correlation between PZ P300 amplitude and total ACC volume in the right hemisphere in schizophrenia patients with less negative symptoms. The results support the assumption that structural changes of the ACC are more pronounced in subgroups of schizophrenia patients with more negative psychopathology. In addition, while right hemisphere ACC volumes significantly differ between schizophrenia subgroups, combining measures of event-related potential (ERP) and ACC volumetry does not add additional information.
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Affiliation(s)
- Ulrich W Preuss
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians University, Nussbaumstrasse 7, D-80336 Munich, Germany.
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Ivleva EI, Morris DW, Moates AF, Suppes T, Thaker GK, Tamminga CA. Genetics and intermediate phenotypes of the schizophrenia--bipolar disorder boundary. Neurosci Biobehav Rev 2010; 34:897-921. [PMID: 19954751 DOI: 10.1016/j.neubiorev.2009.11.022] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 11/20/2009] [Accepted: 11/23/2009] [Indexed: 12/20/2022]
Abstract
Categorization of psychotic illnesses into schizophrenic and affective psychoses remains an ongoing controversy. Although Kraepelinian subtyping of psychosis was historically beneficial, modern genetic and neurophysiological studies do not support dichotomous conceptualization of psychosis. Evidence suggests that schizophrenia and bipolar disorder rather present a clinical continuum with partially overlapping symptom dimensions, neurophysiology, genetics and treatment responses. Recent large scale genetic studies have produced inconsistent findings and exposed an urgent need for re-thinking phenomenology-based approach in psychiatric research. Epidemiological, linkage and molecular genetic studies, as well as studies in intermediate phenotypes (neurocognitive, neurophysiological and anatomical imaging) in schizophrenia and bipolar disorders are reviewed in order to support a dimensional conceptualization of psychosis. Overlapping and unique genetic and intermediate phenotypic signatures of the two psychoses are comprehensively recapitulated. Alternative strategies which may be implicated into genetic research are discussed.
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Affiliation(s)
- Elena I Ivleva
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX 75235, USA.
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Neurophysiological measures of sensory registration, stimulus discrimination, and selection in schizophrenia patients. Curr Top Behav Neurosci 2010; 4:283-309. [PMID: 21312404 DOI: 10.1007/7854_2010_59] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cortical Neurophysiological event related potentials (ERPs) are multidimensional measures of information processing that are well suited to efficiently parse automatic and controlled components of cognition that span the range of deficits exhibited in schizophrenia patients. Components following a stimulus reflect the sequence of neural processes triggered by the stimulus, beginning with early automatic sensory processes and proceeding through controlled decision and response related processes. Previous studies employing ERP paradigms have reported deficits of information processing in schizophrenia across automatic through attention dependent processes including sensory registration (N1), automatic change detection (MMN), the orienting or covert shift of attention towards novel or infrequent stimuli (P3a), and attentional allocation following successful target detection processes (P3b). These automatic and attention dependent information components are beginning to be recognized as valid targets for intervention in the context of novel treatment development for schizophrenia and related neuropsychiatric disorders. In this review, we describe three extensively studied ERP components (N1, mismatch negativity, P300) that are consistently deficient in schizophrenia patients and may serve as genetic endophenotypes and as quantitative biological markers of response outcome.
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Waters F, Price G, Dragović M, Jablensky A. Electrophysiological brain activity and antisaccade performance in schizophrenia patients with first-rank (passivity) symptoms. Psychiatry Res 2009; 170:140-9. [PMID: 19906434 DOI: 10.1016/j.psychres.2008.10.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Revised: 10/12/2008] [Accepted: 10/24/2008] [Indexed: 11/26/2022]
Abstract
Few studies have examined electrophysiological functioning in schizophrenia patients with first-rank (passivity) symptoms (FRS). In this study, we conducted a broad assessment of FRS patients' performance using data collected as part of the Western Australia Family Study of Schizophrenia, with a focus on event-related potential (ERP) measures [P50 suppression, mismatch negativity (MMN), the auditory oddball target (P300)], and the antisaccade task. A total of 39 patients (23 patients with, and 16 patients without FRS) and 80 controls were included. The results showed that patients with FRS had significantly reduced amplitude and longer latencies on the P300, as compared to controls. In addition, patients with FRS demonstrated more abnormalities on antisaccade error measures (error rate, self-correction latencies) relative to controls. On these measures, the performance of patients without FRS was not significantly different from controls. P300 and antisaccade error abnormalities in patients with FRS could not be accounted for by clinical variables, medication effects, or cognitive abilities. These results provide support for the proposal that FRS reflect a specific dysfunction in the monitoring and evaluation of sensory information.
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Affiliation(s)
- Flavie Waters
- Centre for Clinical Research in Neuropsychiatry, Perth 6910, Australia.
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Tan HY, Callicott JH, Weinberger DR. Prefrontal cognitive systems in schizophrenia: towards human genetic brain mechanisms. Cogn Neuropsychiatry 2009; 14:277-98. [PMID: 19634031 DOI: 10.1080/13546800903091665] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Schizophrenia has complex genetic heritability. It is also genetically heterogeneous. To the extent that genes are associated with symptom constellations in schizophrenia, they do so by affecting the development and function of neural systems that mediate the expression of such diverse behavioral, cognitive and perceptual phenomena. The genetic mechanisms of human brain dysfunction remain to be well understood. "Imaging genetics" is an emerging field that attempts to integrate the basic biology of putative disease mechanisms with physiological correlates from the live human brain. Here, we review recent imaging genetics work on prefrontal brain systems associated with working memory and executive function - heritable traits relevant to schizophrenia. Starting with genetic variation in dopaminergic systems (e.g., COMT), we examined the modulation of prefrontal brain networks during active cognitive processing; there is also evidence that variation in the expression of dopamine-related downstream intra-cellular signaling molecules (e.g., AKT1) are implicated. Moreover, these genetic variants evidence epistasis on neuroimaging measures, lending further support to the conceptualization that non-additive combinations of multiple genes modulate active human cognitive brain mechanisms. The imaging genetics platform therefore could extend understanding of genetic mechanisms of human cognitive brain processes relevant to neuropsychiatric disease.
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Affiliation(s)
- Hao-Yang Tan
- Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program, National Institute of Mental Health, National Institute of Health, Bethesda, MD 20892, USA.
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van Kampen D, Deijen JB. SPEM dysfunction and general schizotypy as measured by the SSQ: a controlled study. BMC Neurol 2009; 9:27. [PMID: 19563649 PMCID: PMC2713195 DOI: 10.1186/1471-2377-9-27] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Accepted: 06/29/2009] [Indexed: 11/19/2022] Open
Abstract
Background SPEM dysfunction is a well-known phenomenon in schizophrenia. The principal aim of the present study was to examine whether SPEM dysfunction is already observable in subjects scoring high on a specific measure of schizotypy (SSQ General Schizotypy) that was selected because of its intimate relationship with schizophrenic prodromal unfolding. Methods Applying ANOVAs, we determined the relationship of subjects' scores on SSQ General Schizotypy and eye movements elicited by targets of different speed. We also examined whether there exists an association between our schizotypy measure and pupil size. Results We found more SPEM dysfunction in subjects scoring high on SSQ General Schizotypy than in subjects scoring average on that factor, irrespective of the speed of the target. No relationship was found between baseline pupil size and General Schizotypy. Conclusion The present study provides additional evidence that SPEM dysfunction is associated with schizotypic features that precede the onset of schizophrenia and is already observable in general population subjects that show these features.
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Affiliation(s)
- Dirk van Kampen
- Department of Oncology and Medical Physics, Haukeland University Hospital, N-5021 Bergen, Norway.
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Tan HY. Cognitive Dysfunction in Schizophrenia: A Perspective from the Clinic to Genetic Brain Mechanisms. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2009. [DOI: 10.47102/annals-acadmedsg.v38n5p420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Schizophrenia is a brain disease with differing symptomatic presentations, outcomes, and complex genetic mechanisms. A selection of recent work integrating clinical observations, human brain imaging and genetics will be reviewed. While the mechanics of brain dysfunction in schizophrenia remains to be well understood, the emerging evidence suggests that a number of interacting genetic mechanisms in dopaminergic and glutamatergic systems affect fundamental disease-related cognitive brain processes and may do so early in disease neurodevelopment. The availability of new imaging and genetic technologies, and institutional support for research in the translational neurosciences, extends the hope that increased understanding of these brain processes could yield meaningful clinical applications.
Key words: Cognitive neuroscience, COMT, GRM3, Magnetic resonance imaging
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Galderisi S, Mucci A, Volpe U, Boutros N. Evidence-based medicine and electrophysiology in schizophrenia. Clin EEG Neurosci 2009; 40:62-77. [PMID: 19534300 DOI: 10.1177/155005940904000206] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In research on schizophrenia electrophysiological measures have been investigated to identify biomarkers of the disorder, indices enabling differential diagnosis among psychotic disorders, prognostic indicators or endophenotypes. The present systematic review will focus on the most largely studied electrophysiological indices, i.e., qualitative or quantitative (limited to spectral analysis) EEG and the P300 event-related potential. The PubMed clinical query was used with research methodology filters for each of the following categories: diagnosis/prognosis/ aetiology and a broad sensitive search strategy. The key-words: SCHIZOPHRENIA AND EEG/P3/P300 were used. The search results were then narrowed by including the terms "human" and "English language", and cross-referenced. Systematic reviews and meta-analyses, when available, were also used for cross-referencing. Case reports and studies irrelevant to the topics and methodologies under examination were excluded. The remaining papers were screened to verify the eligibility for this systematic review. Inclusion criteria were: a) a diagnosis of schizophrenia confirmed by DSM-III/ICD-9 criteria (or later editions of the same classification systems); b) the inclusion of both a schizophrenia study group and an healthy control group (when appropriate, i.e., for P300 and quantitative EEG); c) qualitative or spectral EEG findings and amplitude measures for P300. The included studies were then reviewed to verify homogeneity of the results, as well as the presence of the information needed for the present systematic review and meta-analysis. Previous reviews and studies meeting the above requirements (n = 22 for qualitative EEG; n = 45 for spectral EEG and n = 132 for P300) were classified according to the Oxford Centre for Evidence-based Medicine (EBM) levels of evidence criteria. For qualitative EEG as a diagnostic test, the majority of studies predated the introduction of DSM-III and were excluded from the review. Few post DSM-III studies investigated the usefulness of qualitative EEG in the differential diagnosis between schizophrenia and psychosis due to general medical condition. None of them was Oxford CEBM level 3b (non-consecutive-study or cohort-study without consistently-applied reference standard) or better (exploratory or validating cohort-study). No meta-analysis could be conducted due to the lack of reliable quantification methods in the reviewed studies. For spectral EEG as a diagnostic test, most studies qualified as level 4 (case-control study with poor reference standard), and only 24% as level 3b or better. An increase of slow activity in patients is reported by most of these studies. As to meta-analyses examining 29 studies, with 32 independent samples for the delta band and 35 for the theta band, a moderate effect size was found and only 1 study yielded findings in the opposite direction for both measures. There was no identified source for the discrepancy. The analysis of moderator factors included medication, band frequency limits, spectral parameters and disease stage. The medication status was significant for the theta band but the effect was unclear as findings for drug-naïve and drug-free patients were in a different direction. Chronicity had a significant effect on both delta and theta bands, with slow activity increase larger in chronic than in first episode patients. For P3 amplitude reduction as a diagnostic index, 63% of the studies qualified as level 3b or better. Meta-analysis (52 studies, 60 independent samples) results demonstrated a large effect size. None of the studies reported opposite findings. The analysis of moderator factors, including medication status and disease stage, revealed no significant effect on data heterogeneity. In conclusion, the examined indices are good candidates but are not ready yet for clinical applications aimed to improve present diagnostic standards for schizophrenia. Further research carried out according to adequate methodological standards and based on large scale multi-center studies is mandatory.
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Affiliation(s)
- Silvana Galderisi
- Department of Psychiatry, University of Naples SUN, Largo Madonna Grazie, Naples, Italy.
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Allen AJ, Griss ME, Folley BS, Hawkins KA, Pearlson GD. Endophenotypes in schizophrenia: a selective review. Schizophr Res 2009; 109:24-37. [PMID: 19223268 PMCID: PMC2665704 DOI: 10.1016/j.schres.2009.01.016] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 01/11/2009] [Accepted: 01/14/2009] [Indexed: 10/21/2022]
Abstract
BACKGROUND Given the wealth of data in the literature on schizophrenia endophenotypes, it is useful to have one source to reference their frequency data. We reviewed the literature on disease-liability associated variants in structural and functional magnetic resonance images (MRI), sensory processing measures, neuromotor abilities, neuropsychological measures, and physical characteristics in schizophrenia patients (SCZ), their first-degree relatives (REL), and healthy controls (HC). The purpose of this review was to provide a summary of the existing data on the most extensively published endophenotypes for schizophrenia. METHODS We searched PubMed and MedLine for all studies on schizophrenia endophenotypes comparing SCZ to HC and/or REL to HC groups. Percent abnormal values, generally defined as >2 SD from the mean (in the direction of abnormality) and/or associated effect sizes (Cohen's d) were calculated for each study. RESULTS Combined, the articles reported an average 39.4% (SD=20.7%; range=2.2-100%) of abnormal values in SCZ, 28.1% (SD=16.6%; range=1.6-67.0%) abnormal values in REL, and 10.2% (SD=6.7%; range=0.0-34.6%) in HC groups. CONCLUSIONS These findings are reviewed in the context of emerging hypotheses on schizophrenia endophenotypes, as well as a discussion of clustering trends among the various intermediate phenotypes. In addition, programs for future research are discussed, as instantiated in a few recent large-scale studies on multiple endophenotypes across patients, relatives, and healthy controls.
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Affiliation(s)
- Allyssa J. Allen
- Olin Neuropsychiatry Research Center, Institute of Living at Hartford Hospital, 200 Retreat Avenue, Hartford, CT 06106,Corresponding Author: Allyssa J. Allen, Olin Neuropsychiatry Research Center, Whitehall Building, 200 Retreat Avenue, Hartford, CT 06106, Tel: 860-459-7806, Fax: 860-545-7797,
| | - Mélina E. Griss
- Olin Neuropsychiatry Research Center, Institute of Living at Hartford Hospital, 200 Retreat Avenue, Hartford, CT 06106
| | - Bradley S. Folley
- Olin Neuropsychiatry Research Center, Institute of Living at Hartford Hospital, 200 Retreat Avenue, Hartford, CT 06106
| | - Keith A. Hawkins
- Dept. of Psychiatry, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06511
| | - Godfrey D. Pearlson
- Olin Neuropsychiatry Research Center, Institute of Living at Hartford Hospital, 200 Retreat Avenue, Hartford, CT 06106,Dept. of Psychiatry, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06511
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Reduced auditory evoked potential component N100 in schizophrenia--a critical review. Psychiatry Res 2008; 161:259-74. [PMID: 18926573 DOI: 10.1016/j.psychres.2008.03.017] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 09/10/2007] [Accepted: 03/14/2008] [Indexed: 11/21/2022]
Abstract
The role of a reduced N100 (or N1) component of the auditory event related potential as a potential trait marker of schizophrenia is critically discussed in this review. We suggest that the extent of the N100 amplitude reduction in schizophrenia depends on experimental and subject factors, as well as on clinical variables: N100 is more consistently reduced in studies using interstimulus intervals (ISIs) >1 s than in studies using shorter ISIs. An increase of the N100 amplitude by allocation of attention is often lacking in schizophrenia patients. A reduction of the N100 amplitude is nevertheless also observed when such an allocation is not required, proposing that both endogenous and exogenous constituents of the N100 are affected by schizophrenia. N100 is more consistently reduced in medicated than unmedicated patients, but a reduction of the N100 amplitude as a consequence of antipsychotic medication was shown in only two of seven studies. In line with that, the association between the N100 reduction and degree of psychopathology of patients appears to be weak overall. A reduced N100 amplitude is found in first degree relatives of schizophrenia patients, but the risk of developing schizophrenia is not reflected in the N100 amplitude reduction.
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de Wilde OM, Bour LJ, Dingemans PM, Koelman JHTM, Boerée T, Linszen DH. P300 deficits are present in young first-episode patients with schizophrenia and not in their healthy young siblings. Clin Neurophysiol 2008; 119:2721-6. [PMID: 18986832 DOI: 10.1016/j.clinph.2008.08.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 05/27/2008] [Accepted: 08/21/2008] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluated P300 (P3b) abnormalities in young first episode patients with schizophrenia and their healthy young siblings. METHODS An auditory oddball paradigm was used to assess P300 in 53 patients, 27 unaffected siblings and 28 healthy controls. Amplitude and latency of the three midline sites (Fz, Cz, and Pz) were compared between patients, siblings, and controls by a mixed-effects regression model. RESULTS P300 amplitude was significantly reduced in patients with schizophrenia but not in healthy siblings, when compared to healthy controls. P300 latency did not significantly differ between the three groups. CONCLUSIONS P300 amplitude but not latency was found to be affected in young patients with recent onset schizophrenia. However, P300 amplitude and latency were found not to be affected in healthy unaffected young siblings and, therefore, did not qualify as an endophenotype for schizophrenia. SIGNIFICANCE The failure to find the P300 (P3b) abnormality in healthy siblings of patients with schizophrenia is an important finding and should be added to P300 literature.
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Affiliation(s)
- O M de Wilde
- Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Meibergdreef 5, 1105 AZ, Amsterdam, The Netherlands
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Calkins ME, Iacono WG, Ones DS. Eye movement dysfunction in first-degree relatives of patients with schizophrenia: a meta-analytic evaluation of candidate endophenotypes. Brain Cogn 2008; 68:436-61. [PMID: 18930572 DOI: 10.1016/j.bandc.2008.09.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2008] [Indexed: 10/21/2022]
Abstract
Several forms of eye movement dysfunction (EMD) are regarded as promising candidate endophenotypes of schizophrenia. Discrepancies in individual study results have led to inconsistent conclusions regarding particular aspects of EMD in relatives of schizophrenia patients. To quantitatively evaluate and compare the candidacy of smooth pursuit, saccade and fixation deficits in first-degree biological relatives, we conducted a set of meta-analytic investigations. Among 18 measures of EMD, memory-guided saccade accuracy and error rate, global smooth pursuit dysfunction, intrusive saccades during fixation, antisaccade error rate and smooth pursuit closed-loop gain emerged as best differentiating relatives from controls (standardized mean differences ranged from .46 to .66), with no significant differences among these measures. Anticipatory saccades, but no other smooth pursuit component measures were also increased in relatives. Visually-guided reflexive saccades were largely normal. Moderator analyses examining design characteristics revealed few variables affecting the magnitude of the meta-analytically observed effects. Moderate effect sizes of relatives v. controls in selective aspects of EMD supports their endophenotype potential. Future work should focus on facilitating endophenotype utility through attention to heterogeneity of EMD performance, relationships among forms of EMD, and application in molecular genetics studies.
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Affiliation(s)
- Monica E Calkins
- Department of Psychiatry, University of Pennsylvania School of Medicine, Neuropsychiatry Section, Schizophrenia Research Center and Brain Behavior Laboratory, Philadelphia, PA 19104, USA.
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Neuregulin-1 and the P300 waveform--a preliminary association study using a psychosis endophenotype. Schizophr Res 2008; 103:178-85. [PMID: 18571900 DOI: 10.1016/j.schres.2008.03.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 03/10/2008] [Accepted: 03/25/2008] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Neuregulin-1 (NRG1) has been put forward as a susceptibility gene for schizophrenia. We investigated the association between Neuregulin-1 and the P300 wave, a schizophrenia endophenotype. METHODS Participants were 64 patients with DSM-IV schizophrenia or schizoaffective disorder, 97 of their non psychotic relatives and 35 unrelated controls. The P300 wave was extracted from the electroencephalogram whilst the subjects conducted a two-tone discrimination task. The effect of three markers from the core NRG-1 at-risk haplotype including single nucleotide polymorphism SNP8NRG221533 and two microsatellites (478B14-848 and 420M9-1395) on P300 amplitude and latency was examined using multilevel modelling. RESULTS Neuregulin-1 SNP8NRG221533 had a significant influence on P300 latency and the higher the number of C alleles carried, the greater the latency delay [Coef.=32.4 ms; 95%CI: 13.2 to 51.6 ms; p=0.001]. There was no association between latency and NRG1 microsatellites or between amplitude and any of the three markers examined. CONCLUSIONS The P300 latency reflects the speed of neural transmission. We hypothesise that variation in NRG1 may convey risk for schizophrenia by disrupting neural connectivity, possibly white matter integrity, and leading to a slower speed of cognitive processing. This is a preliminary finding in a small sample and requires replication.
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Hanaya R, Koning E, Ferrandon A, Schweitzer A, Andrieux A, Nehlig A. Deletion of the STOP gene, a microtubule stabilizing factor, leads only to discrete cerebral metabolic changes in mice. J Neurosci Res 2008; 86:813-20. [PMID: 17969102 DOI: 10.1002/jnr.21550] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In mice, deletion of the STOP protein leads to subtle anatomic changes and induces depleted synaptic vesicle pools, impaired synaptic plasticity, hyperdopaminergy, and major behavioral disorders alleviated by neuroleptics, hence leading to a schizophrenic-like phenotype. In this study, we applied the quantitative autoradiographic [(14)C]2-deoxyglucose technique to study to what extent the basal rate of cerebral glucose utilization in STOP-knockout (STOP-KO) mice occurs in regions where metabolic changes have been reported in schizophrenic patients. Studies were performed on wild-type, heterozygous, and homozygous STOP-KO mice (7-8 per group). Mice were implanted with femoral artery and vein catheters, and cerebral glucose utilization was quantified over 45 min. Compared with that in wild-type mice, glucose utilization in STOP-KO mice was significantly increased in the olfactory cortex, ventromedial and anterolateral hypothalamus, ventral tegmental area, and substantia nigra pars compacta. Nonsignificant increases, ranging between 9% and 19%, were recorded in the whole auditory system, CA1 pyramidal cell layer, and dorsal raphe. Glucose utilization was also significantly increased in heterozygous mice compared with that in wild-type mice in olfactory cortex. These data might reflect hyperdopaminergic activity, olfactory deficits, and sleep disturbances in STOP-KO mice that have also been reported in schizophrenic patients.
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Abstract
The search for liability genes of the world's 2 major psychotic disorders, schizophrenia and bipolar disorder I (BP-I), has been extremely difficult even though evidence suggests that both are highly heritable. This difficulty is due to the complex and multifactorial nature of these disorders. They encompass several intermediate phenotypes, some overlapping across the 2 psychotic disorders that jointly and/or interactively produce the clinical manifestations. Research of the past few decades has identified several neurophysiological deficits in schizophrenia that frequently occur before the onset of psychosis. These include abnormalities in smooth pursuit eye movements, P50 sensory gating, prepulse inhibition, P300, mismatch negativity, and neural synchrony. Evidence suggests that many of these physiological deficits are distinct from each other. They are stable, mostly independent of symptom state and medications (with some exceptions) and are also observed in non-ill relatives. This suggests a familial and perhaps genetic nature. Some deficits are also observed in the BP-I probands and to a lesser extent their relatives. These deficits in physiological measures may represent the intermediate phenotypes that index small effects of genes (and/or environmental factors). The use of these measures in genetic studies may help the hunt for psychosis liability genes and clarify the extent to which the 2 major psychotic disorders share etio-pathophysiology. In spite of the rich body of work describing these neurophysiological measures in psychotic disorders, challenges remain: Many of the neurophysiological phenotypes are still relatively complex and are associated with low heritability estimates. Further refinement of these physiological phenotypes is needed that could identify specific underlying physiological deficits and thereby improve their heritability estimates. The extent to which these neurophysiological deficits are unique or overlap across BP-I and schizophrenia is unclear. And finally, the clinical and functional consequences of the neurophysiological deficits both in the probands and their relatives are not well described.
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Affiliation(s)
- Gunvant K. Thaker
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, PO Box 21247, Baltimore, MD 21228,To whom correspondence should be addressed; tel: 410-402-6821; fax: 410-402-6021; e-mail:
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Bramon E, Shaikh M, Broome M, Lappin J, Bergé D, Day F, Woolley J, Tabraham P, Madre M, Johns L, Howes O, Valmaggia L, Pérez V, Sham P, Murray RM, McGuire P. Abnormal P300 in people with high risk of developing psychosis. Neuroimage 2008; 41:553-60. [DOI: 10.1016/j.neuroimage.2007.12.038] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 11/28/2007] [Accepted: 12/21/2007] [Indexed: 10/22/2022] Open
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Schulze KK, Hall MH, McDonald C, Marshall N, Walshe M, Murray RM, Bramon E. Auditory P300 in patients with bipolar disorder and their unaffected relatives. Bipolar Disord 2008; 10:377-86. [PMID: 18402626 DOI: 10.1111/j.1399-5618.2007.00527.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES There is evidence that genetic susceptibility may be shared between bipolar disorder (BD) and schizophrenia, but electrophysiological phenotypes which have been extensively used in studies of genetic susceptibility for schizophrenia remain far less explored in bipolar illness. This study assesses whether auditory P300 latency delays and amplitude reductions, which have been demonstrated in patients with schizophrenia and their unaffected first-degree relatives, are associated with familial liability to psychotic bipolar illness. METHODS The P300 auditory evoked potential was obtained using an oddball task from 37 participants with BD who had a history of psychotic symptoms, 38 of their unaffected first-degree relatives and 42 healthy unrelated comparison subjects. Patients and relatives came from families multiply affected with BD or another functional psychotic disorder. P300 amplitude and latency at midline sites were compared between the groups, using linear regression analyses and robust variance estimators for clustered data, including age and gender as covariates. RESULTS Bipolar disorder patients with a history of psychosis and their unaffected relatives showed significantly delayed P300 latency at Pz compared to controls. The groups did not differ in P300 amplitude. CONCLUSIONS P300 latency delays are associated with both psychotic BD and familial liability for this illness. Sample size limited our ability to test for multimodal distribution of P300 measures among relatives, which might be expected if only a subgroup inherits any deficits. In future it will be of interest to directly compare groups of families with psychotic and non-psychotic forms of BD to explore further the role of psychotic symptoms with regard to P300 measures in the disorder. Our results indicate that delayed P300 latency is a promising candidate endophenotype for psychotic BD, as well as schizophrenia, and may reflect the impact of shared susceptibility genes for both types of psychosis.
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Affiliation(s)
- Katja K Schulze
- Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK.
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Tan HY, Callicott JH, Weinberger DR. Intermediate phenotypes in schizophrenia genetics redux: is it a no brainer? Mol Psychiatry 2008; 13:233-8. [PMID: 18285755 DOI: 10.1038/sj.mp.4002145] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Javitt DC, Spencer KM, Thaker GK, Winterer G, Hajós M. Neurophysiological biomarkers for drug development in schizophrenia. Nat Rev Drug Discov 2008; 7:68-83. [PMID: 18064038 PMCID: PMC2753449 DOI: 10.1038/nrd2463] [Citation(s) in RCA: 224] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Schizophrenia represents a pervasive deficit in brain function, leading to hallucinations and delusions, social withdrawal and a decline in cognitive performance. As the underlying genetic and neuronal abnormalities in schizophrenia are largely unknown, it is challenging to measure the severity of its symptoms objectively, or to design and evaluate psychotherapeutic interventions. Recent advances in neurophysiological techniques provide new opportunities to measure abnormal brain functions in patients with schizophrenia and to compare these with drug-induced alterations. Moreover, many of these neurophysiological processes are phylogenetically conserved and can be modelled in preclinical studies, offering unique opportunities for use as translational biomarkers in schizophrenia drug discovery.
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Affiliation(s)
- Daniel C Javitt
- Nathan Kline Institute for Schizophrenia Research/New York University School of Medicine, 140 Old Orangeburg Road, Orangeburg, New York 10962, USA
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Sakai T, Oshima A, Nozaki Y, Ida I, Haga C, Akiyama H, Nakazato Y, Mikuni M. Changes in density of calcium-binding-protein-immunoreactive GABAergic neurons in prefrontal cortex in schizophrenia and bipolar disorder. Neuropathology 2007; 28:143-50. [PMID: 18069969 DOI: 10.1111/j.1440-1789.2007.00867.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There is evidence that GABAergic neurotransmission is altered in mental disorders such as schizophrenia (SCZ) and bipolar disorder (BPD). The calcium-binding proteins (CBPs) calbindin (CB), calretinin (CR), and parvalbumin (PV) are used as markers of specific subpopulations of cortical GABAergic interneurons. We examined the postmortem prefrontal cortical region (Brodmann's area 9) of patients with SCZ and BPD, and of age-matched control subjects, excluding suicide cases. The laminar density of neurons immunoreactive (IR) for three CBPs, namely CB, CR, and PV, was quantified. The densities of CB-IR neurons in layer 2 and PV-IR neurons in layer 4 in the SCZ subjects decreased compared with those in the control subjects. When CBP-IR neurons were classified according to their size, a reduction in the density of medium CB-IR neurons in layer 2 in SCZ subjects and an increase in the density of large CR-IR neurons in layer 2 in BPD subjects were observed. These results suggest that alterations in specific GABAergic neurons are present in mental disorders, and that such alterations may reflect the vulnerability toward the disorders.
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Affiliation(s)
- Tsutomu Sakai
- Department of Psychiatry and Human Behavior, Gunma University Graduate School of Medicine, Gunma, Japan.
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