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Kim S, Lee SW, Lee H, Lee HJ, Lee SJ, Chang Y. Disrupted cognitive network revealed by task-induced brain entropy in schizophrenia. Brain Imaging Behav 2024:10.1007/s11682-024-00909-3. [PMID: 39222212 DOI: 10.1007/s11682-024-00909-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2024] [Indexed: 09/04/2024]
Abstract
Brain entropy (BEN), which measures the amount of information in brain activity, provides a novel perspective for evaluating brain function. Recent studies using resting-state functional magnetic resonance imaging (fMRI) have shown that BEN during rest can help characterize brain function alterations in schizophrenia (SCZ). However, there is a lack of research on BEN using task-evoked fMRI to explore task-dependent cognitive deficits in SCZ. In this study, we evaluate whether the reduced working memory (WM) capacity in SCZ is possibly associated with dynamic changes in task BEN during tasks with high cognitive demands. We analyzed data from 15 patients with SCZ and 15 healthy controls (HC), calculating task BEN from their N-back task fMRI scans. We then examined correlations between task BEN values, clinical symptoms, 2-back task performance, and neuropsychological test scores. Patients with SCZ exhibited significantly reduced task BEN in the cerebellum, hippocampus, parahippocampal gyrus, thalamus, and the middle and superior frontal gyrus (MFG and SFG) compared to HC. In HC, significant positive correlations were observed between task BEN and 2-back accuracy in several brain regions, including the MFG and SFG; such correlations were absent in patients with SCZ. Additionally, task BEN was negatively associated with scores for both positive and negative symptoms in areas including the parahippocampal gyrus among patients with SCZ. In conclusion, our findings indicate that a reduction in BEN within prefrontal and hippocampal regions during cognitively demanding tasks may serve as a neuroimaging marker for SCZ.
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Affiliation(s)
- Seungho Kim
- Department of Medical & Biological Engineering, Kyungpook National University, Daegu, Korea
| | - Sang Won Lee
- Department of Psychiatry, Kyungpook National University Chilgok Hospital, Daegu, Korea
- Department of Psychiatry, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu, 41944, Korea
| | - Hansol Lee
- Department of Medical & Biological Engineering, Kyungpook National University, Daegu, Korea
| | - Hui Joong Lee
- Department of Radiology, Kyungpook National University Hospital, Daegu, Korea
- Department of Radiology, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Seung Jae Lee
- Department of Psychiatry, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu, 41944, Korea.
- Department of Psychiatry, Kyungpook National University Hospital, Daegu, Korea.
| | - Yongmin Chang
- Department of Radiology, Kyungpook National University Hospital, Daegu, Korea.
- Department of Molecular Medicine, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu, 41944, Korea.
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2
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Kassim FM, Tod S, Rodger J, Hood SD, Lee JWY, Albrecht MA, Martin-Iverson MT. Nabilone Impairs Spatial and Verbal Working Memory in Healthy Volunteers. Cannabis Cannabinoid Res 2024; 9:199-211. [PMID: 36201240 DOI: 10.1089/can.2022.0099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Memory impairments and psychosis-like experiences can be adverse effects of cannabis use. However, reports on the cognitive impact of cannabis use are not consistent. There are also limited studies on the psychotomimetic effects of cannabinoid compounds to reveal the association between cannabis and psychosis. Therefore, we investigated the effect of acute cannabinoid intoxication on verbal working memory (VWM) and spatial working memory (SWM) following oral doses of the synthetic cannabinoid agonist, nabilone (1-2 mg, oral). We further investigated the effect of nabilone on psychosis-like experiences (schizotypy scores) and associations of schizotypy with VWM and SWM. Methods: Healthy participants (n=28) completed spatial and digit span tasks across different delay conditions (0, 6, 12, and 18 sec) after receiving nabilone (1-2 mg, PO) or placebo in a randomized, double-blind, counterbalanced, crossover manner. A subset of participants completed a short battery of schizotypy measures (n=25). Results: Nabilone impaired VWM (p=0.03, weak effect size η2=0.02) and SWM (p=0.00016, η2=0.08). Nabilone did not significantly change overall schizotypy scores. Schizotypy scores were negatively correlated with working memory (WM) averaged across all delays and both modalities, under placebo (ρ=-0.41, p=0.04). In addition, there were significant negative correlations between occasions of cannabis use and overall WM averaged scores across drug treatments (ρ=-0.49, p=0.007) and under placebo (ρ=-0.45, p=0.004). The results showed that the drug effect in the less frequent cannabis users was more pronounced on the SWM (p<0.01) and VWM (p<0.01), whereas there appeared to be little drug effect in the frequent cannabis users. Conclusion: Low doses of synthetic cannabinoid impaired SWM and VWM, indicating that exogenous activation of the cannabinoid system influences cognitive performance. Further, the results replicated previous findings that schizotypy is correlated with deficits in WM. Clinical Trial Registry Name: Nabilone and caffeine effects on the perceptions of visually, auditory, tactile and multimodal illusions in healthy volunteers. Clinical Trial Registration Number: CT-2018-CTN-02561 (Therapeutic Goods Administration Clinical Trial Registry) and ACTRN12618001292268 (The Australian New Zealand Clinical Trials Registry).
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Affiliation(s)
- Faiz M Kassim
- Psychopharmacology Research Unit, Discipline of Pharmacology, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Sophie Tod
- Psychopharmacology Research Unit, Discipline of Pharmacology, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Jennifer Rodger
- Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
- Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
| | - Sean D Hood
- Division of Psychiatry, Medical School, University of Western Australia, Perth, Western Australia, Australia
| | - Joseph W Y Lee
- Division of Psychiatry, Medical School, University of Western Australia, Perth, Western Australia, Australia
| | - Matthew A Albrecht
- Western Australian Centre for Road Safety Research, School of Psychological Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Mathew T Martin-Iverson
- Psychopharmacology Research Unit, Discipline of Pharmacology, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
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3
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Ye H, Zhu X, Wang K, Song L, Yang X, Li F, Fan Q. Study of differences between patients with schizophrenia and healthy people in semantic processing. Psych J 2021; 10:698-706. [PMID: 34346183 DOI: 10.1002/pchj.471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 05/30/2020] [Accepted: 06/02/2021] [Indexed: 11/07/2022]
Abstract
Semantic processing is important in language comprehension and production, and context can facilitate understanding and accelerate processing speed by pre-activating semantically related words. There are many studies suggesting that patients with schizophrenia have inferior language ability. This study was aimed to examine the differences between patients with schizophrenia and healthy people in semantic processing with Chinese classifier-noun pairs rating tasks. Participants were required to finish rating tasks to judge acceptability of classifier-noun pairs. Also, the Positive and Negative Syndrome Scale (PANSS) was conducted in the schizophrenia group. According to results of variance analysis, schizophrenic patients' accuracy of judgment on the acceptability of classifier-noun pairs differed from the control group (F = 4.13, p < .05), and the contextual effect of classifier constraint could be observed in healthy people (F(1, 31) = 5.38, p < .05) but not in patients with schizophrenia (F(1, 25) = 3.55, p = .07), indicating that they failed to use the contextual information to facilitate language comprehension as healthy people. Stepwise linear regression analysis found that hostility, poor impulse control and suspiciousness/persecution and preoccupation in the PANSS may have contributed to the reduced sensitivity in the rating in patients (t = -2.38-3.80, p < .05).
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Affiliation(s)
- Huiling Ye
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinyu Zhu
- School of Foreign Language, Shanghai Jiao Tong University, Shanghai, China
| | - Kaifeng Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lisheng Song
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaohu Yang
- School of Foreign Language, Shanghai Jiao Tong University, Shanghai, China
| | - Fei Li
- School of Foreign Language, Shanghai Jiao Tong University, Shanghai, China
| | - Qing Fan
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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4
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Caruana N, Seymour K. Bottom-up processing of fearful and angry facial expressions is intact in schizophrenia. Cogn Neuropsychiatry 2021; 26:183-198. [PMID: 33752551 DOI: 10.1080/13546805.2021.1902794] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Judgments of emotion from faces are reportedly impaired in schizophrenia. However, it is unclear whether this is due to a top-down cognitive deficit in evaluating sensory information or a fundamental bottom-up perturbation in the early stages of face encoding. This study examined whether deficits in emotion processing reflect imprecision in the initial preconscious registration of emotional face expressions within the visual system. METHODS Using continuous flash suppression (CFS), we presented participants (18 patients with schizophrenia, 8M/10F; 20 healthy controls, 13M/7F) with fearful and angry faces. Previous CFS research on healthy participants reveals that fearful facial expressions gain privileged access to awareness over angry faces-demonstrating the visual system's ability to discriminate these emotions at a preconscious level. We used this same approach to probe the integrity of early emotion encoding whilst minimising the potential contribution of any top-down cognitive biases on perceptual judgments. RESULTS In both groups, fearful faces were perceived faster than angry faces, with no differences observed between patients and controls. CONCLUSIONS Emotion processing difficulties in schizophrenia are unlikely to reflect an early sensory deficit, but rather a deficit in social cognition that has a top-down impact on the conscious evaluation of facial expressions.
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Affiliation(s)
- Nathan Caruana
- Department of Cognitive Science, Macquarie University, Sydney, Australia.,Perception in Action Research Centre, Macquarie University, Sydney, Australia
| | - Kiley Seymour
- School of Psychology, Western Sydney University, Sydney, Australia.,The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Sydney, Australia.,Max Planck Institute for Biological Cybernetics, Tübingen, Germany
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5
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Ichinose M, Park S. Mechanisms Underlying Visuospatial Working Memory Impairments in Schizophrenia. Curr Top Behav Neurosci 2019; 41:345-367. [PMID: 31407240 DOI: 10.1007/7854_2019_99] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Working memory deficits are observed in the vast majority of individuals diagnosed with schizophrenia and those at risk for the disorder. Working memory impairments are present during the prodromal stage and persist throughout the course of schizophrenia. Given the importance of cognition in functional outcome, working memory deficits are an important therapeutic target for schizophrenia. This chapter examines mechanisms underlying working memory deficits in schizophrenia, focusing on the roles of perception and attention in the encoding process. Lastly, we present a comprehensive discussion of neural oscillation and internal noise in the context of the etiology of working memory deficits in schizophrenia and introduce noninvasive treatment strategies that could improve encoding processes.
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Affiliation(s)
- Megan Ichinose
- Department of Psychology, Vanderbilt University, Nashville, TN, USA
| | - Sohee Park
- Department of Psychology, Vanderbilt University, Nashville, TN, USA.
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6
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Lin SZ, Wu YK, Su YA, Si TM. Prospective memory in non-psychotic first-degree relatives of patients with schizophrenia: a meta-analysis. Neuropsychiatr Dis Treat 2019; 15:1563-1571. [PMID: 31289442 PMCID: PMC6565992 DOI: 10.2147/ndt.s203729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/04/2019] [Indexed: 12/16/2022] Open
Abstract
Prospective memory (PM) could be impaired in the non-psychotic first-degree relatives of patients with schizophrenia. This meta-analysis systematically examined the PM of non-psychotic first-degree relatives of patients with schizophrenia. Both Chinese and English databases were systematically searched for articles from the inception of the databases through November 13, 2018. Case-control studies of PM in non-psychotic first-degree relatives of patients with schizophrenia were included in the analyses. Confidence intervals (CIs) and standardized mean differences (SMDs) were calculated utilizing the random effects model. Four studies (n=268) that compared PM performance between non-psychotic first-degree relatives of patients with schizophrenia (n=136) and healthy controls (n=132) were included. Three studies were rated as "high quality", while the quality of evidence of the three outcomes included in this meta-analysis was moderate. Compared with the healthy controls, the non-psychotic first-degree relatives of patients with schizophrenia showed impairments in overall PM (two studies, n=127; SMD: -0.46; 95% CI=-0.82, -0.11, P=0.01; I=0%), event-based PM (EBPM) (four studies, n=268; SMD: -0.56; 95% CI=-0.80, -0.31, P<0.00001; I=0%), and time-based PM (TBPM) (four studies, n=268; SMD: -0.66; 95% CI=-0.90, -0.41, P<0.00001; I=0%). This meta-analysis demonstrated that the overall PM, EBPM, and TBPM might be impaired in the non-psychotic first-degree relatives of patients with schizophrenia.
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Affiliation(s)
- Shi-Ze Lin
- Quanzhou Mental Health Center, The Third Hospital of Quanzhou, Quanzhou, Fujian Province, People's Republic of China.,Institute of Mental Health, Peking University Sixth Hospital, Beijing, People's Republic of China
| | - Yan-Kun Wu
- Institute of Mental Health, Peking University Sixth Hospital, Beijing, People's Republic of China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, People's Republic of China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, People's Republic of China
| | - Yun-Ai Su
- Institute of Mental Health, Peking University Sixth Hospital, Beijing, People's Republic of China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, People's Republic of China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, People's Republic of China
| | - Tian-Mei Si
- Institute of Mental Health, Peking University Sixth Hospital, Beijing, People's Republic of China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, People's Republic of China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, People's Republic of China
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7
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Tahir RA, Wu H, Javed N, Khalique A, Khan SAF, Mir A, Ahmed MS, Barreto GE, Qing H, Ashraf GM, Sehgal SA. Pharmacoinformatics and molecular docking reveal potential drug candidates against Schizophrenia to target TAAR6. J Cell Physiol 2018; 234:13263-13276. [PMID: 30569503 DOI: 10.1002/jcp.27999] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/30/2018] [Indexed: 11/10/2022]
Abstract
Schizophrenia (SZ) is a complex disabling disorder that leads to the mental disability and afflicts 1% of the world's total population and placed in top ten medical disorders. In current work, bioinformatics analyses were carried out on Trace amine (TA)-associated receptor 6 (TAAR6) to recognize the potential drugs and compounds against SZ. Comparative modeling and threading-based approaches were utilized for the structure prediction of TAAR6. Fifty-nine predicted structures were evaluated by various model assessment techniques and final model having only eight amino acids in the outlier region and 98.5% overall quality factor was chosen for further pharmacoinformatics and molecular docking analyses. From an extensive literature review, 11 Food and Drug Administration (FDA) approved drugs were analyzed by computational techniques and Aripiprazole was found as the most effective drug against SZ by targeting TAAR6. Here, we report five novel molecules which exhibited the highest binding affinity, effective drug properties, and interestingly, observed better results than the approved selected drugs against SZ by targeting TAAR6. The docking analyses revealed that Arg-92, Trp-98, Gln-191, Thr-192, Ala-290, Cys-291, Tyr-293, and Glu-294 residues were observed as critical interacting residues in receptor-ligand interactions. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties, Lipinski rule of five, highest binding affinity coupled with virtual screening (VS), and pharmacophore modeling approach illustrated that aripiprazole (-8.6 kcal/mol) and TAAR6_0094 (-9.3 kcal/mol) are potential inhibitors for targeting TAAR6. It is suggested that schizophrenic patients have to use Aripiprazole for the medication of SZ by targeting TAAR6 and develop effective therapies by utilizing scrutinized novel compound.
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Affiliation(s)
- Rana Adnan Tahir
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Sciences, Beijing Institute of Technology, Beijing, China.,Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Islamabad, Pakistan
| | - Hao Wu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Naima Javed
- Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Islamabad, Pakistan
| | - Anila Khalique
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | | | - Asif Mir
- Department of Bioinformatics and Biotechnology, International Islamic University Islamabad, Islamabad, Pakistan
| | - Muhammad Saad Ahmed
- Department of Biological Engineering/Institute of Biotransformation and Synthetic Biosystem, School of Life Sciences, Beijing Institute of Technology, Beijing, China
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Sciences, Beijing Institute of Technology, Beijing, China
| | - Ghulam Md Ashraf
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Sheikh Arslan Sehgal
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Department of Biosciences, COMSATS University Islamabad, Sahiwal Campus, Islamabad, Pakistan.,University of Chinese Academy of Sciences, Beijing, China
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8
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Zhou HY, Li Z, Xie DJ, Xu T, Cheung EEF, Li H, Chan RCK. Heritability estimates of spatial working memory and set-shifting in a healthy Chinese twin sample: A preliminary study. Psych J 2018; 7:144-151. [DOI: 10.1002/pchj.227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 06/06/2018] [Accepted: 07/02/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Han-yu Zhou
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Department of Psychology; University of Chinese Academy of Sciences; Beijing China
- Department of Psychology; Renmin University of China; Beijing China
| | - Zhi Li
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Department of Psychology; University of Chinese Academy of Sciences; Beijing China
| | - Dong-jie Xie
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Department of Psychology; University of Chinese Academy of Sciences; Beijing China
| | - Ting Xu
- Key Laboratory of Behavioral Sciences and Magnetic Resonance Imaging Research Center; Institute of Psychology, Chinese Academy of Sciences; Beijing China
- Center for the Developing Brain; Child Mind Institute; New York New York USA
| | - Eric E. F. Cheung
- Castle Peak Hospital; Hong Kong Special Administrative Region; Tuen Mun China
| | - Huanhuan Li
- Department of Psychology; Renmin University of China; Beijing China
| | - Raymond C. K. Chan
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Department of Psychology; University of Chinese Academy of Sciences; Beijing China
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9
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Zouraraki C, Karamaouna P, Karagiannopoulou L, Giakoumaki SG. Schizotypy-Independent and Schizotypy-Modulated Cognitive Impairments in Unaffected First-Degree Relatives of Schizophrenia-spectrum Patients. Arch Clin Neuropsychol 2017; 32:1010-1025. [PMID: 28383650 DOI: 10.1093/arclin/acx029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 03/27/2017] [Indexed: 11/14/2022] Open
Abstract
Objective The aim of the study was to compare the neurocognitive profile of unaffected first-degree relatives of schizophrenia patients with control individuals, controlling for different schizotypal traits. Method One hundred and fifteen adult unaffected first-degree relatives of schizophrenia-spectrum patients and 122 controls were tested for schizotypy with the Schizotypal Personality Questionnaire. They also underwent a thorough neurocognitive assessment with a range of tasks covering several aspects of executive functioning. Between-group differences in cognition were examined first with multivariate analysis of variance and then with a series of multivariate analyses of covariance, including the schizotypal dimensions as covariates. Results The relatives had higher scores on all schizotypal dimensions compared with controls and poorer planning, problem solving, strategy formation and working memory, irrespective of schizotypal traits. They also scored lower in executive working memory and verbal fluency. The difference in executive working memory was sensitive to the effects of paranoid and negative schizotypy (both dimensions abolished the between-group difference) whereas the difference in verbal fluency was sensitive only to the effects of paranoid schizotypy. Neither cognitive-perceptual nor disorganized schizotypy accounted for any differences in neurocognition between relatives and the controls. Conclusions Impairments in planning, problem solving, strategy formation and working memory are "core" impairments in the schizophrenia-spectrum, possibly due to high heritability effects in these functions. Impairments in executive working memory and verbal fluency are associated with paranoid and negative schizotypy, possibly due to alterations in a common fronto-temporo-parietal neural network.
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Affiliation(s)
- Chrysoula Zouraraki
- Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno 74100, Crete, Greece
| | - Penny Karamaouna
- Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno 74100, Crete, Greece
| | - Leda Karagiannopoulou
- Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno 74100, Crete, Greece
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10
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Thomas EH, Bozaoglu K, Rossell SL, Gurvich C. The influence of the glutamatergic system on cognition in schizophrenia: A systematic review. Neurosci Biobehav Rev 2017; 77:369-387. [DOI: 10.1016/j.neubiorev.2017.04.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/24/2017] [Accepted: 04/06/2017] [Indexed: 12/22/2022]
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11
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Harave VS, Shivakumar V, Kalmady SV, Narayanaswamy JC, Varambally S, Venkatasubramanian G. Neurocognitive Impairments in Unaffected First-degree Relatives of Schizophrenia. Indian J Psychol Med 2017; 39:250-253. [PMID: 28615756 PMCID: PMC5461832 DOI: 10.4103/0253-7176.207335] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Neurocognitive impairments of attention and executive functioning are trait abnormalities in schizophrenia, and these are considered to be endophenotypes. These deficits have been convincingly linked to prefrontal cortical functioning. In this study, we examined the cognitive performance in the domains of attention and executive functioning among first-degree relatives of Indian people with schizophrenia (high-risk [HR] patients) compared to healthy controls (HC). MATERIALS AND METHODS Siblings of patients with DSM-IV schizophrenia, HR patients (n = 17), were compared with HC (n = 30) (matched as a group for age, sex, years of education, and handedness) using the following neurocognitive tests for attention and executive function - digit span test (DST), trail making test, letter-number sequencing (LNS), and spatial span test. RESULTS HR patients had significantly deficient performance in attention and executive function tasks (DST-forward [P < 0.001], DST-backward [P < 0.001], spatial span-forward [P < 0.001], spatial span-backward [P < 0.001], and LNS [P < 0.001]). CONCLUSIONS This study replicates the findings that neurocognitive deficits involving executive function task performance, attention, and working memory, which are considered as principal features in patients with schizophrenia, are also significantly present in the first-degree relatives of patients. Thus, these neurocognitive parameters can be considered as potential endophenotypes in schizophrenia.
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Affiliation(s)
- Virupaksha Shanmugam Harave
- Department of Psychiatry, Translational Psychiatry Laboratory, The Schizophrenia Clinic, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Venkataram Shivakumar
- Department of Psychiatry, Translational Psychiatry Laboratory, The Schizophrenia Clinic, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Sunil V Kalmady
- Department of Psychiatry, Translational Psychiatry Laboratory, The Schizophrenia Clinic, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Janardhanan C Narayanaswamy
- Department of Psychiatry, Translational Psychiatry Laboratory, The Schizophrenia Clinic, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Shivarama Varambally
- Department of Psychiatry, Translational Psychiatry Laboratory, The Schizophrenia Clinic, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Ganesan Venkatasubramanian
- Department of Psychiatry, Translational Psychiatry Laboratory, The Schizophrenia Clinic, Neurobiology Research Centre, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
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12
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Noort MVD, Struys E, Perriard B, Staudte H, Yeo S, Lim S, Bosch P. Schizophrenia and depression: The relation between sleep quality and working memory. Asian J Psychiatr 2016; 24:73-78. [PMID: 27931914 DOI: 10.1016/j.ajp.2016.08.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 08/28/2016] [Accepted: 08/30/2016] [Indexed: 11/28/2022]
Abstract
Sleep is known to be markedly disturbed in patients with depression, but in patients with schizophrenia these problems are underestimated. This research aimed to determine if a relationship existed between sleep problems in patients with schizophrenia and with depression and their reduced working memory (WM) performance. Thirty outpatients with schizophrenia, 30 outpatients with depression, and 30 healthy control participants were enrolled in this study. All participants completed a sleep questionnaire (i.e., Pittsburgh Sleep Quality Index (PSQI)), two simple WM tasks tapping only its storage component (i.e., digit span forward and backward task), and two complex WM tasks tapping both its storage and processing components (i.e., letter-number sequencing and reading span task). The results showed that neither psychiatric group differed from the healthy controls on simple WM tasks. Patients with schizophrenia did not differ from those with depression in the performance of simple or complex WM tasks. However, patients with schizophrenia, and, to a lesser degree, patients with depression performed significantly worse than the healthy control participants on complex WM tasks, which was visible in lower WM scores for patients with depression and in slower information processing, as well, for patients with schizophrenia. Finally, a significant negative relationship was found between the PSQI score and the reading span task scores; thus, participants with worse performance tended to report more sleep problems. To conclude, sleep needs to receive more priority when treating patients with depression and especially patients with schizophrenia because better sleep improves (working) memory performance and daily functioning.
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Affiliation(s)
- Maurits van den Noort
- Research Group of Pain and Neuroscience, Kyung Hee University, #47 Gyeonghuidae-Gil, Dongdaemun-Gu, Seoul 130-701, Republic of Korea; Brussels Institute for Applied Linguistics, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
| | - Esli Struys
- Center of Linguistics, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
| | - Benoît Perriard
- Department of Psychology, Université de Fribourg, Rue de Faucigny 2, 1700 Fribourg, Switzerland.
| | - Heike Staudte
- Psychiatric Research Institute, LVR-Klinik Bedburg-Hau, Nassauerallee 93-97, 47533 Kleve, Germany.
| | - Sujung Yeo
- Department of Acupuncture & Meridian of Oriental Medicine, Sang Ji University, 83 Sangjidae-gil, Wonju 26339, Republic of Korea.
| | - Sabina Lim
- Research Group of Pain and Neuroscience, Kyung Hee University, #47 Gyeonghuidae-Gil, Dongdaemun-Gu, Seoul 130-701, Republic of Korea.
| | - Peggy Bosch
- Research Group of Pain and Neuroscience, Kyung Hee University, #47 Gyeonghuidae-Gil, Dongdaemun-Gu, Seoul 130-701, Republic of Korea; Psychiatric Research Institute, LVR-Klinik Bedburg-Hau, Nassauerallee 93-97, 47533 Kleve, Germany; Donders Institute for Brain, Cognition, and Behaviour, Centre for Cognition, Radboud University Nijmegen, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands, The Netherlands.
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13
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Zouraraki C, Tsaousis I, Karamaouna P, Karagiannopoulou L, Roussos P, Bitsios P, Giakoumaki SG. Associations of differential schizotypal dimensions with executive working memory: A moderated-mediation analysis. Compr Psychiatry 2016; 71:39-48. [PMID: 27621208 DOI: 10.1016/j.comppsych.2016.08.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND Increased schizotypal traits are observed in a percentage of the general population and in the schizophrenia-spectrum and have been associated with impairments in working memory. In this study we examined the effects of four schizotypal dimensions [Negative (NegS), Paranoid (ParS), Cognitive-Perceptual (CPS), Disorganized (DiS)] on executive working memory (EWM), as mediated by set-shifting, planning and control inhibition. We also examined whether these associations are moderated by family-history of psychosis. METHODS Our sample consisted of 110 unaffected first-degree relatives of schizophrenia-spectrum patients and 120 control individuals. Schizotypy was assessed with the Schizotypal Personality Questionnaire. Participants were also tested with the Letter-Number Sequencing, Wisconsin Card Sorting, Stroop Color-Word and Stockings of Cambridge tasks. The effects of set-shifting, control inhibition and planning on the relationship between schizotypy and EWM were examined with mediation analyses. Moderated-mediation analyses examined potential moderating effects of group membership (unaffected relative/community participant). RESULTS All mediators were significant in the relationship between NegS and EWM. The effects of ParS were mediated only by set-shifting and planning. Planning and control inhibition were the only significant mediators on the effects of CPS and DiS on EWM, respectively. The moderated-mediation analyses revealed that these findings apply only in the community group. CONCLUSIONS We found that the effects of different schizotypal dimensions on EWM are mediated by other cognitive processes in individuals without personal/family history of psychosis. This is probably due to either more severe impairments in the cognitive processes of the relatives or restrictions in our sample and study-design.
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Affiliation(s)
- Chrysoula Zouraraki
- Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece
| | - Ioannis Tsaousis
- Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece
| | - Penny Karamaouna
- Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece
| | | | - Panos Roussos
- Department of Psychiatry, Department of Genetics and Genomic Sciences, Institute for Genomics and Multiscale Biology, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Panos Bitsios
- Department of Psychiatry and Behavioral Sciences, Faculty of Medicine, University of Crete, Heraklion, 71003, Crete, Greece
| | - Stella G Giakoumaki
- Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece.
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14
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Kos MZ, Carless MA, Peralta J, Blackburn A, Almeida M, Roalf D, Pogue-Geile MF, Prasad K, Gur RC, Nimgaonkar V, Curran JE, Duggirala R, Glahn DC, Blangero J, Gur RE, Almasy L. Exome Sequence Data From Multigenerational Families Implicate AMPA Receptor Trafficking in Neurocognitive Impairment and Schizophrenia Risk. Schizophr Bull 2016; 42:288-300. [PMID: 26405221 PMCID: PMC4753604 DOI: 10.1093/schbul/sbv135] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Schizophrenia is a mental disorder characterized by impairments in behavior, thought, and neurocognitive performance. We searched for susceptibility loci at a quantitative trait locus (QTL) previously reported for abstraction and mental flexibility (ABF), a cognitive function often compromised in schizophrenia patients and their unaffected relatives. Exome sequences were determined for 134 samples in 8 European American families from the original linkage study, including 25 individuals with schizophrenia or schizoaffective disorder. At chromosome 5q32-35.3, we analyzed 407 protein-altering variants for association with ABF and schizophrenia status. For replication, significant, Bonferroni-corrected findings were tested against cognitive traits in Mexican American families (n = 959), as well as interrogated for schizophrenia risk using GWAS results from the Psychiatric Genomics Consortium (PGC). From the gene SYNPO, rs6579797 (MAF = 0.032) shows significant associations with ABF (P = .015) and schizophrenia (P = .040), as well as jointly (P = .0027). In the Mexican American pedigrees, rs6579797 exhibits significant associations with IQ (P = .011), indicating more global effects on neurocognition. From the PGC results, other SYNPO variants were identified with near significant effects on schizophrenia risk, with a local linkage disequilibrium block displaying signatures of positive selection. A second missense variant within the QTL, rs17551608 (MAF = 0.19) in the gene WWC1, also displays a significant effect on schizophrenia in our exome sequences (P = .038). Remarkably, the protein products of SYNPO and WWC1 are interaction partners involved in AMPA receptor trafficking, a brain process implicated in synaptic plasticity. Our study reveals variants in these genes with significant effects on neurocognition and schizophrenia risk, identifying a potential pathogenic mechanism for schizophrenia spectrum disorders.
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Affiliation(s)
- Mark Z. Kos
- South Texas Diabetes and Obesity Institute, School of Medicine, The University of Texas Rio Grande Valley, San Antonio, TX;,*To whom correspondence should be addressed; South Texas Diabetes and Obesity Institute, School of Medicine, The University of Texas Rio Grande Valley, San Antonio, TX 78229, US; tel: 210-585-9772, fax: 210-582-5836, e-mail:
| | - Melanie A. Carless
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX
| | - Juan Peralta
- South Texas Diabetes and Obesity Institute, School of Medicine, The University of Texas Rio Grande Valley, San Antonio, TX
| | - August Blackburn
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX
| | - Marcio Almeida
- South Texas Diabetes and Obesity Institute, School of Medicine, The University of Texas Rio Grande Valley, San Antonio, TX
| | - David Roalf
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | | | - Konasale Prasad
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA
| | - Ruben C. Gur
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | | | - Joanne E. Curran
- South Texas Diabetes and Obesity Institute, School of Medicine, The University of Texas Rio Grande Valley, San Antonio, TX
| | - Ravi Duggirala
- South Texas Diabetes and Obesity Institute, School of Medicine, The University of Texas Rio Grande Valley, San Antonio, TX
| | - David C. Glahn
- Department of Psychiatry, Olin Neuropsychiatric Research Center, Yale School of Medicine, Hartford, CT
| | - John Blangero
- South Texas Diabetes and Obesity Institute, School of Medicine, The University of Texas Rio Grande Valley, San Antonio, TX
| | - Raquel E. Gur
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Laura Almasy
- South Texas Diabetes and Obesity Institute, School of Medicine, The University of Texas Rio Grande Valley, San Antonio, TX
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15
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Schwarz E, Tost H, Meyer-Lindenberg A. Working memory genetics in schizophrenia and related disorders: An RDoC perspective. Am J Med Genet B Neuropsychiatr Genet 2016; 171B:121-31. [PMID: 26365198 DOI: 10.1002/ajmg.b.32353] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/08/2015] [Indexed: 12/29/2022]
Abstract
Improved classification of mental disorders through neurobiological measures will require a set of traits that map to transdiagnostic subgroups of patients and align with heritable, core psychopathological processes at the center of the disorders of interest. A promising candidate is working memory (WM) function, for which deficits have been reported across multiple diagnostic entities including schizophrenia, bipolar disorder, ADHD, autism, and major depressive disorder. Here we review genetic working memory associations and their brain functional correlates from the perspective of identifying patient subgroups across conventional diagnostic boundaries, explore the utility of multimodal investigations integrating functional information at the neural systems level and explore potential limitations as well as future directions for research.
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Affiliation(s)
- Emanuel Schwarz
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Heike Tost
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Andreas Meyer-Lindenberg
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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16
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Effects of genetic variations in NRG1 on cognitive domains in patients with schizophrenia and healthy individuals. Psychiatr Genet 2015; 25:147-54. [DOI: 10.1097/ypg.0000000000000087] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Substantial SNP-based heritability estimates for working memory performance. Transl Psychiatry 2014; 4:e438. [PMID: 25203169 PMCID: PMC4203010 DOI: 10.1038/tp.2014.81] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/11/2014] [Accepted: 07/26/2014] [Indexed: 01/13/2023] Open
Abstract
Working memory (WM) is an important endophenotype in neuropsychiatric research and its use in genetic association studies is thought to be a promising approach to increase our understanding of psychiatric disease. As for any genetically complex trait, demonstration of sufficient heritability within the specific study context is a prerequisite for conducting genetic studies of that trait. Recently developed methods allow estimating trait heritability using sets of common genetic markers from genome-wide association study (GWAS) data in samples of unrelated individuals. Here we present single-nucleotide polymorphism (SNP)-based heritability estimates (h(2)SNP) for a WM phenotype. A Caucasian sample comprising a total of N=2298 healthy and young individuals was subjected to an N-back WM task. We calculated the genetic relationship between all individuals on the basis of genome-wide SNP data and performed restricted maximum likelihood analyses for variance component estimation to derive the h(2)SNP estimates. Heritability estimates for three 2-back derived WM performance measures based on all autosomal chromosomes ranged between 31 and 41%, indicating a substantial SNP-based heritability for WM traits. These results indicate that common genetic factors account for a prominent part of the phenotypic variation in WM performance. Hence, the application of GWAS on WM phenotypes is a valid method to identify the molecular underpinnings of WM.
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18
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Forsyth JK, McEwen SC, Gee DG, Bearden CE, Addington J, Goodyear B, Cadenhead KS, Mirzakhanian H, Cornblatt BA, Olvet DM, Mathalon DH, McGlashan TH, Perkins DO, Belger A, Seidman LJ, Thermenos HW, Tsuang MT, van Erp TGM, Walker EF, Hamann S, Woods SW, Qiu M, Cannon TD. Reliability of functional magnetic resonance imaging activation during working memory in a multi-site study: analysis from the North American Prodrome Longitudinal Study. Neuroimage 2014; 97:41-52. [PMID: 24736173 PMCID: PMC4065837 DOI: 10.1016/j.neuroimage.2014.04.027] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 02/06/2014] [Accepted: 04/06/2014] [Indexed: 10/25/2022] Open
Abstract
Multi-site neuroimaging studies offer an efficient means to study brain functioning in large samples of individuals with rare conditions; however, they present new challenges given that aggregating data across sites introduces additional variability into measures of interest. Assessing the reliability of brain activation across study sites and comparing statistical methods for pooling functional data are critical to ensuring the validity of aggregating data across sites. The current study used two samples of healthy individuals to assess the feasibility and reliability of aggregating multi-site functional magnetic resonance imaging (fMRI) data from a Sternberg-style verbal working memory task. Participants were recruited as part of the North American Prodrome Longitudinal Study (NAPLS), which comprises eight fMRI scanning sites across the United States and Canada. In the first study sample (n=8), one participant from each home site traveled to each of the sites and was scanned while completing the task on two consecutive days. Reliability was examined using generalizability theory. Results indicated that blood oxygen level-dependent (BOLD) signal was reproducible across sites and was highly reliable, or generalizable, across scanning sites and testing days for core working memory ROIs (generalizability ICCs=0.81 for left dorsolateral prefrontal cortex, 0.95 for left superior parietal cortex). In the second study sample (n=154), two statistical methods for aggregating fMRI data across sites for all healthy individuals recruited as control participants in the NAPLS study were compared. Control participants were scanned on one occasion at the site from which they were recruited. Results from the image-based meta-analysis (IBMA) method and mixed effects model with site covariance method both showed robust activation in expected regions (i.e. dorsolateral prefrontal cortex, anterior cingulate cortex, supplementary motor cortex, superior parietal cortex, inferior temporal cortex, cerebellum, thalamus, basal ganglia). Quantification of the similarity of group maps from these methods confirmed a very high (96%) degree of spatial overlap in results. Thus, brain activation during working memory function was reliable across the NAPLS sites and both the IBMA and mixed effects model with site covariance methods appear to be valid approaches for aggregating data across sites. These findings indicate that multi-site functional neuroimaging can offer a reliable means to increase power and generalizability of results when investigating brain function in rare populations and support the multi-site investigation of working memory function in the NAPLS study, in particular.
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Affiliation(s)
| | - Sarah C McEwen
- University of California, Los Angeles, Los Angeles, CA, United States
| | - Dylan G Gee
- University of California, Los Angeles, Los Angeles, CA, United States
| | - Carrie E Bearden
- University of California, Los Angeles, Los Angeles, CA, United States
| | | | | | | | | | | | | | - Daniel H Mathalon
- University of California, San Francisco, San Francisco, CA, United States
| | | | - Diana O Perkins
- University of North Carolina, Chapel Hill, Chapel Hill, NC, United States
| | - Aysenil Belger
- University of North Carolina, Chapel Hill, Chapel Hill, NC, United States
| | - Larry J Seidman
- Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Heidi W Thermenos
- Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Ming T Tsuang
- University of California, San Diego, San Diego, CA, United States
| | | | | | | | | | - Maolin Qiu
- Yale University, New Haven, CT, United States
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19
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Executive functioning and psychopathological profile in relatives of individuals with deficit v. non-deficit schizophrenia: a pilot study. Epidemiol Psychiatr Sci 2014; 23:85-97. [PMID: 23545096 PMCID: PMC6998377 DOI: 10.1017/s2045796013000140] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Aims. Heterogeneity of schizophrenia is known to be reflected in neuropsychological functioning of patients, but its expression in relatives is understudied. This study aims at exploring relationship between executive functioning and clinical profiles of first-degree relatives of patients who are classified as having or not having the deficit subtype of schizophrenia (DSRELs v. non-DSRELs), with the prediction of greater executive impairment in DSRELs. Methods. DSRELs (n = 15) and non-DSRELs (n = 40) were compared with community controls (CCs, n = 55) on executive functioning measured by the Wisconsin Card Sorting Test (WCST) and the phonemic verbal fluency (PVF), and clinical measures. Effects of psychopathology and intelligence quotient (IQ) measures were investigated to determine their association with executive performance. Results. DSRELs showed more executive dysfunction on WCST and poorer social functioning than CCs and more severe negative symptoms than non-DSRELs. Differences on WCST-categories achieved (WCST-CA) remained significant after adjustment for clinical confounders and IQ. WCST-CA was associated with apathy and paranoid ideation only within the DSREL subgroup. Conclusions. Executive functioning and negative symptoms are severely impaired in first-degree relatives of deficit syndrome patients, thus suggesting that some neurocognitive deficits in patients may be transmitted within families according to the pathophysiology of the probands.
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20
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Cao XY, Li Z, Metcalfe HM, Yang TX, Tan SP, Wang Y, Hong XH, Li ZJ, Yu X, Cheung EFC, Neumann DL, Shum DHK, Chan RCK. The nature and extent of working memory dysfunction in schizophrenia. Psych J 2013; 2:175-82. [PMID: 26271362 DOI: 10.1002/pchj.30] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 05/15/2013] [Indexed: 01/17/2023]
Abstract
This study aimed to examine verbal and visual-spatial working memory (WM) dysfunction in patients with schizophrenia. We compared 60 patients with schizophrenia with 57 healthy controls (matched for age, educational level, and IQ) on three WM tasks. Patients with schizophrenia performed significantly more poorly than healthy controls on verbal, visual, and spatial WM tests. Moreover, WM deficits were inversely associated with both the positive and negative symptoms of the patients. Taken together, these findings suggest that there are pervasive WM impairments in patients with schizophrenia. In addition, clinical features may play a significant role in the expression of WM deficits.
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Affiliation(s)
- Xiao-Yan Cao
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Zhi Li
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Hugo M Metcalfe
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Tian-Xiao Yang
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | | | - Ya Wang
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Xiao-Hong Hong
- Mental Health Center, Shantou University, Shantou, China
| | - Zhan-Jiang Li
- Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Xin Yu
- Institute of Mental Health, the Sixth Affiliated Hospital, Peking University, Beijing, China
| | - Eric F C Cheung
- Castle Peak Hospital, Hong Kong Special Administrative Region, China
| | - David L Neumann
- Behavioural Basis of Health Research Program, Griffith Health Institute, Griffith University, Gold Coast, Australia.,School of Applied Psychology, Griffith University, Gold Coast, Australia
| | - David H K Shum
- Behavioural Basis of Health Research Program, Griffith Health Institute, Griffith University, Gold Coast, Australia
| | - Raymond C K Chan
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
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21
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Landgraf S, Osterheider M. "To see or not to see: that is the question." The "Protection-Against-Schizophrenia" (PaSZ) model: evidence from congenital blindness and visuo-cognitive aberrations. Front Psychol 2013; 4:352. [PMID: 23847557 PMCID: PMC3696841 DOI: 10.3389/fpsyg.2013.00352] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 05/30/2013] [Indexed: 12/12/2022] Open
Abstract
The causes of schizophrenia are still unknown. For the last 100 years, though, both “absent” and “perfect” vision have been associated with a lower risk for schizophrenia. Hence, vision itself and aberrations in visual functioning may be fundamental to the development and etiological explanations of the disorder. In this paper, we present the “Protection-Against-Schizophrenia” (PaSZ) model, which grades the risk for developing schizophrenia as a function of an individual's visual capacity. We review two vision perspectives: (1) “Absent” vision or how congenital blindness contributes to PaSZ and (2) “perfect” vision or how aberrations in visual functioning are associated with psychosis. First, we illustrate that, although congenitally blind and sighted individuals acquire similar world representations, blind individuals compensate for behavioral shortcomings through neurofunctional and multisensory reorganization. These reorganizations may indicate etiological explanations for their PaSZ. Second, we demonstrate that visuo-cognitive impairments are fundamental for the development of schizophrenia. Deteriorated visual information acquisition and processing contribute to higher-order cognitive dysfunctions and subsequently to schizophrenic symptoms. Finally, we provide different specific therapeutic recommendations for individuals who suffer from visual impairments (who never developed “normal” vision) and individuals who suffer from visual deterioration (who previously had “normal” visual skills). Rather than categorizing individuals as “normal” and “mentally disordered,” the PaSZ model uses a continuous scale to represent psychiatrically relevant human behavior. This not only provides a scientific basis for more fine-grained diagnostic assessments, earlier detection, and more appropriate therapeutic assignments, but it also outlines a trajectory for unraveling the causes of abnormal psychotic human self- and world-perception.
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Affiliation(s)
- Steffen Landgraf
- Department for Forensic Psychiatry and Psychotherapy, District Hospital, University Regensburg Regensburg, Germany ; Berlin School of Mind and Brain, Humboldt Universität zu Berlin Berlin, Germany
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22
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McGuire KA, Blahnik MM, Sponheim SR. Discrimination within Recognition Memory in Schizophrenia. Behav Sci (Basel) 2013; 3:273-297. [PMID: 25379239 PMCID: PMC4217626 DOI: 10.3390/bs3020273] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 05/21/2013] [Accepted: 05/30/2013] [Indexed: 12/15/2022] Open
Abstract
Episodic memory is one of the most affected cognitive domains in schizophrenia. First-degree biological relatives of individuals with schizophrenia also have been found to exhibit a similar, but milder, episodic memory deficit. Unlike most studies that focus on the percent of previously presented items recognized, the current investigation sought to further elucidate the nature of memory dysfunction associated with schizophrenia by examining the discrimination of old and new material during recognition (measured by d') to consider false recognition of new items. Using the Recurring Figures Test and the California Verbal Learning Test (CVLT), we studied a sample of schizophrenia probands and the first-degree biological relatives of patients with schizophrenia, as well as probands with bipolar disorder and first-degree biological relatives to assess the specificity of recognition memory dysfunction to schizophrenia. The schizophrenia sample had poorer recognition discrimination in both nonverbal and verbal modalities; no such deficits were identified in first-degree biological relatives or bipolar disorder probands. Discrimination in schizophrenia and bipolar probands failed to benefit from the geometric structure in the designs in the manner that controls did on the nonverbal test. Females performed better than males in recognition of geometric designs. Episodic memory dysfunction in schizophrenia is present for a variety of stimulus domains and reflects poor use of item content to increase discrimination of old and new items.
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Affiliation(s)
- Kathryn A. McGuire
- Minneapolis Veterans Affairs Health Care System, One Veterans Drive, Minneapolis, MN 55417, USA; E-Mails: (M.M.B.); (S.R.S.)
- Department of Psychiatry, University of Minnesota, F282/2A West, 2450 Riverside Avenue, Minneapolis, MN 55454, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-612-725-2044; Fax: +1-612-467-2144
| | - Melanie M. Blahnik
- Minneapolis Veterans Affairs Health Care System, One Veterans Drive, Minneapolis, MN 55417, USA; E-Mails: (M.M.B.); (S.R.S.)
| | - Scott R. Sponheim
- Minneapolis Veterans Affairs Health Care System, One Veterans Drive, Minneapolis, MN 55417, USA; E-Mails: (M.M.B.); (S.R.S.)
- Department of Psychiatry, University of Minnesota, F282/2A West, 2450 Riverside Avenue, Minneapolis, MN 55454, USA
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23
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Li Z, Zheng B, Deng W, Liu X, Zheng Z, Li T. Multi-components of evoked-brain potentials in deficit and nondeficit schizophrenia. Asia Pac Psychiatry 2013; 5:69-79. [PMID: 23857807 DOI: 10.1111/appy.12030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 12/02/2012] [Indexed: 02/05/2023]
Abstract
INTRODUCTION The present study aims to detect the specific and common impairment index relative to evoked brain potentials (EBPS ) in deficit schizophrenia (DS) and nondeficit schizophrenia (NDS), and investigates the relationship between EBPs and clinical variables. METHODS The study used EBPs in 21 patients with DS, 38 patients with NDS, and 50 healthy controls (HCs) to investigate P300 waves, mismatch negative (MMN), sensory gating (SG) P50 and contingent negative variation (CNV). A comparison of three groups and the relationship between EBPs and clinical variables were performed using general linear model analyses and partial correlation, respectively. RESULTS Compared with HCs, both groups of patients showed delayed N1 , N2 , and P3a latency, and reduced N1 and N2 amplitude. The MMN showed delayed latency. The P50 ratios and the inhibited ratios were impaired, whereas SG loss ratios increased. CNV amplitude was reduced. Compared with HCs, NDS showed delayed latency of S2'-C in CNV, whereas DS showed shortened latency. Only NDS, when compared with HCs, showed delayed latency of P3b , Also, only DS, when compared with HCs, showed delayed latency of point A in CNV. Latency of point A in CNV of DS, correlated with a poorer Global Assessment of Functioning Scale (6 weeks) and was independent of clinical characteristics. DISCUSSION Schizophrenia represents a clinical syndrome with shared impairments in brain function, whereas DS is a relatively homogeneous subgroup of schizophrenia with unique pathophysiological changes.
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Affiliation(s)
- Zhe Li
- Mental Health Center and the Psychiatric Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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24
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Ozomaro U, Wahlestedt C, Nemeroff CB. Personalized medicine in psychiatry: problems and promises. BMC Med 2013; 11:132. [PMID: 23680237 PMCID: PMC3668172 DOI: 10.1186/1741-7015-11-132] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 04/19/2013] [Indexed: 01/29/2023] Open
Abstract
The central theme of personalized medicine is the premise that an individual's unique physiologic characteristics play a significant role in both disease vulnerability and in response to specific therapies. The major goals of personalized medicine are therefore to predict an individual's susceptibility to developing an illness, achieve accurate diagnosis, and optimize the most efficient and favorable response to treatment. The goal of achieving personalized medicine in psychiatry is a laudable one, because its attainment should be associated with a marked reduction in morbidity and mortality. In this review, we summarize an illustrative selection of studies that are laying the foundation towards personalizing medicine in major depressive disorder, bipolar disorder, and schizophrenia. In addition, we present emerging applications that are likely to advance personalized medicine in psychiatry, with an emphasis on novel biomarkers and neuroimaging.
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Affiliation(s)
- Uzoezi Ozomaro
- University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
| | - Claes Wahlestedt
- University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
- Center for Therapeutic Innovation, Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Psychiatry and Behavioral Sciences, University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
| | - Charles B Nemeroff
- University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
- Center for Therapeutic Innovation, Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Psychiatry and Behavioral Sciences, University of Miami, Leonard M. Miller School of Medicine, Miami, FL, USA
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Yabuki Y, Nakagawasai O, Tadano T, Fukunaga K. [Imaging monitoring method of CaMKII activity by immunohistochemical analysis in schizophrenic model rats]. YAKUGAKU ZASSHI 2013; 133:501-6. [PMID: 23649390 DOI: 10.1248/yakushi.12-00278-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Schizophrenia is characterized by various behavioral abnormalities including cognitive dysfunction. Neonatal ventral hippocampus (NVH)-lesioned rats had been known as neurodevelopmental animal model similar to schizophrenia. Previous observations indicate that postpubertal NVH-lesioned rats exhibit impairments in prepulse inhibition (PPI), spontaneous locomotion, social interaction behavior and working memory. Here, we document the neurochemical basis of those defects in NVH-lesioned rats. Since Ca²⁺/calmodulin-dependent protein kinase II (CaMKII), which is NMDA receptor downstream kinase, is essential for memory and learning acquisition, we developed a protocol to monitor the spatial changes in CaMKII autophosphorylation using immunohistochemical imaging of whole brain slices with anti-autophosphorylated CaMKII antibody in order to address mechanisms underlying impaired cognitive function in NVH-lesioned rats. Immunohistochemical analyses using anti-autophosphorylated CaMKII antibody revealed that CaMKII autophosphorylation was significantly reduced in the medial prefrontal cortex (mPFC) of NVH-lesioned rats compared with control animals. This immunohistochemical technique is useful to investigate temporal and special changes in CaMKII activity in rodent brain and to evaluate drugs to improve the cognitive impairment.
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Affiliation(s)
- Yasushi Yabuki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University
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Yabuki Y, Nakagawasai O, Moriguchi S, Shioda N, Onogi H, Tan-No K, Tadano T, Fukunaga K. Decreased CaMKII and PKC activities in specific brain regions are associated with cognitive impairment in neonatal ventral hippocampus-lesioned rats. Neuroscience 2013; 234:103-15. [DOI: 10.1016/j.neuroscience.2012.12.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 12/22/2012] [Accepted: 12/28/2012] [Indexed: 11/28/2022]
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Silverstein SM, Wang Y, Keane BP. Cognitive and neuroplasticity mechanisms by which congenital or early blindness may confer a protective effect against schizophrenia. Front Psychol 2013; 3:624. [PMID: 23349646 PMCID: PMC3552473 DOI: 10.3389/fpsyg.2012.00624] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Accepted: 12/31/2012] [Indexed: 12/12/2022] Open
Abstract
Several authors have noted that there are no reported cases of people with schizophrenia who were born blind or who developed blindness shortly after birth, suggesting that congenital or early (C/E) blindness may serve as a protective factor against schizophrenia. By what mechanisms might this effect operate? Here, we hypothesize that C/E blindness offers protection by strengthening cognitive functions whose impairment characterizes schizophrenia, and by constraining cognitive processes that exhibit excessive flexibility in schizophrenia. After briefly summarizing evidence that schizophrenia is fundamentally a cognitive disorder, we review areas of perceptual and cognitive function that are both impaired in the illness and augmented in C/E blindness, as compared to healthy sighted individuals. We next discuss: (1) the role of neuroplasticity in driving these cognitive changes in C/E blindness; (2) evidence that C/E blindness does not confer protective effects against other mental disorders; and (3) evidence that other forms of C/E sensory loss (e.g., deafness) do not reduce the risk of schizophrenia. We conclude by discussing implications of these data for designing cognitive training interventions to reduce schizophrenia-related cognitive impairment, and perhaps to reduce the likelihood of the development of the disorder itself.
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Affiliation(s)
- Steven M. Silverstein
- University Behavioral HealthCare, University of Medicine and Dentistry of New JerseyPiscataway, NJ, USA
- Department of Psychiatry, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical SchoolPiscataway, NJ, USA
| | - Yushi Wang
- University Behavioral HealthCare, University of Medicine and Dentistry of New JerseyPiscataway, NJ, USA
| | - Brian P. Keane
- University Behavioral HealthCare, University of Medicine and Dentistry of New JerseyPiscataway, NJ, USA
- Department of Psychiatry, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical SchoolPiscataway, NJ, USA
- Rutgers University Center for Cognitive SciencePiscataway, NJ, USA
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Scala S, Lasalvia A, Cristofalo D, Bonetto C, Ruggeri M. Neurocognitive profile and its association with psychopathology in first-degree relatives of patients with schizophrenia. a case-control study. Psychiatry Res 2012; 200:137-43. [PMID: 22652345 DOI: 10.1016/j.psychres.2012.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 04/30/2012] [Accepted: 05/05/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND People with schizophrenia show a broad range of neurocognitive deficits, which are considered as core features of the disorder and are thought to be partly heritable. Similar deficits, albeit at a lesser degree, have been also found in their healthy biological relatives. These deficits, if better characterized, might represent underlying vulnerable traits for psychosis. METHODS This case-control study compared neurocognitive functioning of adult first-degree relatives of patients with schizophrenia (SCZ-RELs) (n=55) with healthy control subjects (n=55) and explored its association with the negative symptoms. Subjects in both study and control group were assessed with an extensive neurocognitive test battery (Trail Making test, Phonemic Verbal fluency, Wisconsin Card Sorting Test, Bushke Fuld Test, Stroop Test, n-Back and Digit span) and a set of clinical measures (SANS, GAF and DAS). RESULTS SCZ-RELs were more significantly impaired on executive function tasks (i.e. Wisconsin Card Sorting Test and the Phonemic Verbal fluency) and displayed significantly more severe negative symptoms and poorer social functioning than control subjects. Significant correlations between neurocognitive measures and negative symptoms were found in the study group, whereas no significant correlations were detected among the controls. DISCUSSION Subtle executive impairments, associated with negative symptoms, are shown to be evident in healthy relatives of patients with schizophrenia. These deficits, which reflect subtle dysfunction in concept formation, flexibility and mental shifting, may be seen as potential phenotypic markers of vulnerability for schizophrenia. This raises the question of underlying prefrontal dysfunction as core feature of the disorder.
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Affiliation(s)
- Silvia Scala
- Department of Public Health and Community Medicine, Section of Psychiatry, University of Verona, P.le L.A. Scuro, 10 37134 Verona, Italy.
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Small-world networks in individuals at ultra-high risk for psychosis and first-episode schizophrenia during a working memory task. Neurosci Lett 2012; 535:35-9. [PMID: 23262086 DOI: 10.1016/j.neulet.2012.11.051] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 11/13/2012] [Accepted: 11/29/2012] [Indexed: 11/23/2022]
Abstract
Disturbances of functional interaction between different brain regions have been hypothesized to be the major pathophysiological mechanism underlying the cognitive deficits of schizophrenia. We investigated the small-world functional networks in individuals at ultra-high risk (UHR) for psychosis, first-episode schizophrenia (FESPR) patients, and healthy controls. All participants underwent the electroencephalogram during a control task and a working memory (WM) task. Small-world properties of the theta band were reduced in FESPR relative to controls during the WM task. Small-worldness of the UHR during the WM task exhibited intermediate value between that of controls and FESPR. These results imply that the suboptimal organization of the brain network may play a pivotal role in the schizophrenia pathophysiology.
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Abstract
While longitudinal studies of children treated for brain tumors have consistently revealed declines on measures of intellectual functioning, greater specification of cognitive changes following treatment is imperative for isolating vulnerable neural systems and developing targeted interventions. Accordingly, this cross-sectional study evaluated the performance of childhood brain tumor survivors (n = 50) treated with conformal radiation therapy, solid tumor survivors (n = 40) who had not received central nervous system (CNS) -directed therapy, and healthy sibling controls (n = 40) on measures of working memory [Digit Span and computerized self-ordered search (SOS) tasks]. Findings revealed childhood brain tumor survivors were impaired on both traditional [Digit Span Backward- F(2,127) = 5.98; p < .01] and experimental [SOS-Verbal- F(2,124) = 4.18; p < .05; SOS-Object- F(2,126) = 5.29; p < .01] measures of working memory, and performance on working memory measures correlated with intellectual functioning (Digit Span Backward- r = .45; p < .0001; SOS- r = -.32 to -.26; p < .01). Comparison of performance on working memory tasks to recognition memory tasks (computerized delayed match-to-sample) offered some support for greater working memory impairment. This pattern of findings is consistent with vulnerability in functional networks that include prefrontal brain regions and has implications for the clinical management of children with brain tumors.
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Abstract
Biomarkers are chemical and physiologic parameters that can provide reliable and predictive information about the course and treatment of a given illness. Biomarkers are being increasingly sought after in other medical conditions, and in some instances (eg, breast cancer therapy) are beginning to be incorporated into clinical decision making. There is a confluence of research investigating potential biomarkers for schizophrenia. This article reviews early progress and strategies for evaluating biomarkers, as well as how this approach can advance the treatment of schizophrenia toward personalized medicine.
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Affiliation(s)
- Anilkumar Pillai
- Department of Psychiatry and Health Behavior, Medical College of Georgia, Georgia Health Sciences University, 997 Saint Sebastian Way, Augusta, GA 30912, USA
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Mayer JS, Park S. Working memory encoding and false memory in schizophrenia and bipolar disorder in a spatial delayed response task. JOURNAL OF ABNORMAL PSYCHOLOGY 2012; 121:784-794. [PMID: 22708888 PMCID: PMC4161120 DOI: 10.1037/a0028836] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Working memory (WM) impairment is a core feature of schizophrenia, but the contributions of different WM components are not yet specified. Here, we investigated the potential role of inefficient encoding in reduced WM performance in patients with schizophrenia (PSZ). Twenty-eight PSZ, 16 patients with bipolar disorder (PBP), 16 unaffected and unmedicated relatives of PSZ (REL), and 29 demographically matched healthy controls (HC) performed a spatial delayed response task with either low or high WM demands. The demands on attentional selection were also manipulated by presenting distractor stimuli during encoding in some of the trials. After each trial, participants rated their level of response confidence. This allowed us to analyze different types of WM responses. WM was severely impaired in PSZ compared to HC; this reduction was mainly due to an increase in the amount of false memory responses (incorrect responses that were given with high confidence) rather than an increase in the amount of incorrect and not-confident responses. Although PBP showed WM impairments, they did not have increased false memory errors. In contrast, reduced WM in REL was also accompanied by an increase in false memory errors. The presentation of distractors led to a decline in WM performance, which was comparable across groups indicating that attentional selection was intact in PSZ. These findings suggest that inefficient WM encoding is responsible for impaired WM in schizophrenia and point to differential mechanisms underlying WM impairments in PSZ and PBP.
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Affiliation(s)
| | - Sohee Park
- Department of Psychology, Vanderbilt University
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Hu M, Chen J, Li L, Zheng Y, Wang J, Guo X, Wu R, Zhao J. Semantic fluency and executive functions as candidate endophenotypes for the early diagnosis of schizophrenia in Han Chinese. Neurosci Lett 2011; 502:173-7. [PMID: 21827833 DOI: 10.1016/j.neulet.2011.07.037] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 07/19/2011] [Accepted: 07/25/2011] [Indexed: 11/19/2022]
Abstract
Neurocognitive deficits are recognized as core features of schizophrenia. The aim of this study was to compare the cognitive performance of antipsychotic, drug-naive patients with first-episode schizophrenia (FES patients) to their healthy siblings and to healthy controls from the Han Chinese population for exploring potential endophenotypes for the early detection of schizophrenia. A battery of cognitive assessment tools was used to measure seven cognitive domains in matched groups consisting of 56 subjects each. Cognitive tests included the grooved pegboard test (GPT), the category fluency test (CFT), the trail making test A (TMT-A), the Wechsler memory scale-III spatial span test (WMS-III SST), the Hopkins verbal learning test-revised (HVLT-R), the brief visuospatial memory test-revised (BVMT-R), the paced auditory serial addition test (PASAT), and the Wisconsin card sorting test-64 cards version (WCST-64). The performances of FEP patients were inferior to normal controls on all neuropsychological tests, while siblings were lower than healthy controls in many of the same tasks. Patients' performances were lower than siblings' on all tests except for the CFT, the WMS-III SST backward test, and four subtests of the WCST-64. Our data suggest that FEP patients exhibited pronounced impairment of fine motor skills, speed of processing, attention, verbal memory, visual memory, and executive function, while siblings exhibited deficits intermediate between those of schizophrenic patients and the control group. Semantic fluency function and executive function may be potential endophenotypes for the early diagnosis of schizophrenia.
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Affiliation(s)
- Maorong Hu
- Institute of Mental Health, the Second Xiangya Hospital, Central South University, Changsha, PR China
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Lazar NL, Neufeld RWJ, Cain DP. Contribution of nonprimate animal models in understanding the etiology of schizophrenia. J Psychiatry Neurosci 2011; 36:E5-29. [PMID: 21247514 PMCID: PMC3120891 DOI: 10.1503/jpn.100054] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Schizophrenia is a severe psychiatric disorder that is characterized by positive and negative symptoms and cognitive impairments. The etiology of the disorder is complex, and it is thought to follow a multifactorial threshold model of inheritance with genetic and neurodevelop mental contributions to risk. Human studies are particularly useful in capturing the richness of the phenotype, but they are often limited to the use of correlational approaches. By assessing behavioural abnormalities in both humans and rodents, nonprimate animal models of schizophrenia provide unique insight into the etiology and mechanisms of the disorder. This review discusses the phenomenology and etiology of schizophrenia and the contribution of current nonprimate animal models with an emphasis on how research with models of neuro transmitter dysregulation, environmental risk factors, neurodevelopmental disruption and genetic risk factors can complement the literature on schizophrenia in humans.
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Affiliation(s)
- Noah L Lazar
- Department of Psychology, University of Western Ontario, London, Ont.
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Chan RCK, Wang Y, Yan C, Song LL, Wang YN, Shi YF, Gong QY, Cheung EFC. Contribution of specific cognitive dysfunction to people with schizotypal personality. Psychiatry Res 2011; 186:71-5. [PMID: 20667601 DOI: 10.1016/j.psychres.2010.06.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 06/21/2010] [Accepted: 06/21/2010] [Indexed: 10/19/2022]
Abstract
The current study aimed to determine whether there is a specific neurocognitive deficit in individuals with schizotypal personality features. One hundred and fifty-nine healthy participants and 62 schizotypal individuals completed a comprehensive battery of cognitive tests. The cognitive functions captured by the battery could be reduced to 6 factors. Significant difference was found between participants with schizotypal features and healthy controls in allocation, verbal memory and marginally in working memory. Schizotypal traits tended to correlate with some of the cognitive factors, especially allocation, verbal memory and working memory.
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Affiliation(s)
- Raymond C K Chan
- Neuropsychology and Applied Cognitive Neuroscience Laboratory; Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
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Gaspar PA, Ruiz S, Zamorano F, Altayó M, Pérez C, Bosman CA, Aboitiz F. P300 amplitude is insensitive to working memory load in schizophrenia. BMC Psychiatry 2011; 11:29. [PMID: 21324141 PMCID: PMC3049741 DOI: 10.1186/1471-244x-11-29] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 02/15/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Working memory (WM) tasks usually elicit a P300 ERP component, whose amplitude decreases with increasing WM load. So far, this effect has not been studied in schizophrenics (SZs), a group that is considered to have an aberrant brain connectivity and impairments in WM capacity. The aim of this study was to determine the dependency of the P300 component on WM load in a sample of SZ subjects. METHODS We recorded 26 subjects (13 SZ patients and their matched controls) with an 80-channel electroencephalogram. Subjects performed an N-back task, a WM paradigm that manipulates the number of items to be stored in memory. RESULTS In healthy subjects, P300 amplitude was highest in the low WM load condition, and lowest in both the attentional control condition and the high WM load condition. In contrast, SZs evidenced low P300 amplitude in all conditions. A significant between group difference in P300 amplitude was evidenced only at the low WM load condition (1 -back), being smaller in SZs. CONCLUSIONS SZ subjects display a lower than normal P300 amplitude, which does not vary as a function of memory load. These results are consistent with a general impairment in WM capacity in these patients.
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Affiliation(s)
- Pablo A Gaspar
- Clínica Psiquiátrica Universitaria, Hospital Clínico de la Universidad de Chile, Santiago, Chile.
| | - Sergio Ruiz
- Institute of Medical Psychology and Behavioural Neurobiology, Tübingen, Germany,Graduate School of Neural and Behavioural Sciences, International Max Planck Research School. Tübigen, Germany,Centro Interdisciplinario de Neurociencia, Departamento de Psiquiatría, Escuela de Medicina, Pontificia Universidad Católica de Chile. Santiago, Chile
| | - Francisco Zamorano
- Centro Interdisciplinario de Neurociencia, Departamento de Psiquiatría, Escuela de Medicina, Pontificia Universidad Católica de Chile. Santiago, Chile
| | - Marcela Altayó
- Centro Interdisciplinario de Neurociencia, Departamento de Psiquiatría, Escuela de Medicina, Pontificia Universidad Católica de Chile. Santiago, Chile
| | - Carolina Pérez
- Centro Interdisciplinario de Neurociencia, Departamento de Psiquiatría, Escuela de Medicina, Pontificia Universidad Católica de Chile. Santiago, Chile
| | - Conrado A Bosman
- Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging. Radboud University Nijmegen, The Netherlands
| | - Francisco Aboitiz
- Centro Interdisciplinario de Neurociencia, Departamento de Psiquiatría, Escuela de Medicina, Pontificia Universidad Católica de Chile. Santiago, Chile
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Lin PI, Shuldiner AR. Rethinking the genetic basis for comorbidity of schizophrenia and type 2 diabetes. Schizophr Res 2010; 123:234-43. [PMID: 20832248 DOI: 10.1016/j.schres.2010.08.022] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 07/29/2010] [Accepted: 08/12/2010] [Indexed: 11/16/2022]
Abstract
The co-occurrence of schizophrenia (SCZ) and type 2 diabetes mellitus (T2D) has been well documented. This review article focuses on the hypothesis that the co-occurrence of SCZ and T2D may be, at least in part, driven by shared genetic factors. Previous genetic studies of T2D and SCZ evidence have disclosed a number of overlapped risk loci. However, the putative common genetic factors for SCZ and T2D remain inconclusive due to inconsistent findings. A systemic review of methods of identifying genetic loci contributing to the comorbidity link between SCZ and T2D is hence needed. In the current review article, we have discussed several different approaches to localizing the shared susceptibility genes for these two diseases. To begin with, one could start with probing the gene involved in both glucose and dopamine metabolisms. Additionally, hypothesis-free genome-wide association studies (GWAS) may provide more clues to the common genetic basis for these two diseases. Genetic similarities inferred from GWAS may shed some light on the genetic mechanism underlying the comorbidity link between SCZ and T2D. Meanwhile, endophenotypes (e.g., adiponectin level in T2D and working memory in SCZ) may serve as alternative phenotypes that are more directly influenced by genes than target diseases. Hence, endophenotypes of these diseases may be more tractable to identification. To summarize, novel approaches are needed to dissect the complex genetic basis of the comorbidity of SCZ and T2D.
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Affiliation(s)
- P I Lin
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, United States.
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Henseler I, Falkai P, Gruber O. Disturbed functional connectivity within brain networks subserving domain-specific subcomponents of working memory in schizophrenia: relation to performance and clinical symptoms. J Psychiatr Res 2010; 44:364-72. [PMID: 19837416 DOI: 10.1016/j.jpsychires.2009.09.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 08/07/2009] [Accepted: 09/08/2009] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Disturbed interregional functional connectivity has been hypothesized to be a promising marker of schizophrenia. The relationship between working memory (WM) impairment, disturbed functional connectivity, and the characteristic symptoms of schizophrenia, however, remains elusive. METHODS We used functional MRI (fMRI) to investigate in patients with schizophrenia and matched controls the patterns of functional connectivity during the performance of different tasks selectively engaging subcomponent processes of working memory. RESULTS Compared with controls, patients showed reduced connectivity of the prefrontal cortex with the intraparietal cortex and the hippocampus and abnormal negative interactions between the ventrolateral and dorsolateral prefrontal cortex during the non-articulatory maintenance of phonological information. During the maintenance of visuospatial information, patients presented reduced connectivity between regions in the superior parietal and occipital cortex, as well as enhanced positive connectivity of the frontal eye field with visual processing areas. DISCUSSION Our findings suggest complex dysregulations within the networks supporting working memory functions in schizophrenia, which manifest as decreased positive and abnormal negative interactions. Correlations between the connection strength and WM performance suggest that these dysregulations may be neurofunctional correlates of the WM deficits seen in schizophrenia. Altered prefronto-hippocampal and parieto-occipital connectivity was further found to be associated with higher positive symptoms, providing a possible explanation for the development of delusions and disorganization symptoms. CONCLUSION The present findings can help to better understand the relationship between altered patterns of synchronized brain activity and the cognitive and clinical symptoms of schizophrenia.
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Affiliation(s)
- Ilona Henseler
- Centre for Translational Research in Systems Neuroscience and Clinical Psychiatry, Department of Psychiatry and Psychotherapy, Georg August University, D-37075 Goettingen, Germany.
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Keshavan MS, Kulkarni S, Bhojraj T, Francis A, Diwadkar V, Montrose DM, Seidman LJ, Sweeney J. Premorbid cognitive deficits in young relatives of schizophrenia patients. Front Hum Neurosci 2010; 3:62. [PMID: 20300465 PMCID: PMC2839849 DOI: 10.3389/neuro.09.062.2009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2009] [Accepted: 11/20/2009] [Indexed: 02/05/2023] Open
Abstract
Neurocognitive deficits in schizophrenia (SZ) are thought to be stable trait markers that predate the illness and manifest in relatives of patients. Adolescence is the age of maximum vulnerability to the onset of SZ and may be an opportune "window" to observe neurocognitive impairments close to but prior to the onset of psychosis. We reviewed the extant studies assessing neurocognitive deficits in young relatives at high risk (HR) for SZ and their relation to brain structural alterations. We also provide some additional data pertaining to the relation of these deficits to psychopathology and brain structural alterations from the Pittsburgh Risk Evaluation Program (PREP). Cognitive deficits are noted in the HR population, which are more severe in first-degree relatives compared to second-degree relatives and primarily involve psychomotor speed, memory, attention, reasoning, and social-cognition. Reduced general intelligence is also noted, although its relationship to these specific domains is underexplored. Premorbid cognitive deficits may be related to brain structural and functional abnormalities, underlining the neurobiological basis of this illness. Cognitive impairments might predict later emergence of psychopathology in at-risk subjects and may be targets of early remediation and preventive strategies. Although evidence for neurocognitive deficits in young relatives abounds, further studies on their structural underpinnings and on their candidate status as endophenotypes are needed.
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Affiliation(s)
- Matcheri S Keshavan
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Massachusetts Mental Health Center, Harvard Medical School Boston, MA, USA
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Emotion–cognition interactions in schizophrenia: Implicit and explicit effects of facial expression. Neuropsychologia 2010; 48:997-1002. [DOI: 10.1016/j.neuropsychologia.2009.11.023] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 10/13/2009] [Accepted: 11/24/2009] [Indexed: 11/18/2022]
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Patients with schizophrenia show deficits of working memory maintenance components in circuit-specific tasks. Eur Arch Psychiatry Clin Neurosci 2010; 260:519-25. [PMID: 20169354 PMCID: PMC2953632 DOI: 10.1007/s00406-010-0107-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2009] [Accepted: 02/03/2010] [Indexed: 10/29/2022]
Abstract
Working memory (WM) deficits are a neuropsychological core finding in patients with schizophrenia and also supposed to be a potential endophenotype of schizophrenia. Yet, there is a large heterogeneity between different WM tasks which is partly due to the lack of process specificity of the tasks applied. Therefore, we investigated WM functioning in patients with schizophrenia using process- and circuit-specific tasks. Thirty-one patients with schizophrenia and 47 controls were tested with respect to different aspects of verbal and visuospatial working memory using modified Sternberg paradigms in a computer-based behavioural experiment. Total group analysis revealed significant impairment of patients with schizophrenia in each of the tested WM components. Furthermore, we were able to identify subgroups of patients showing different patterns of selective deficits. Patients with schizophrenia exhibit specific and, in part, selective WM deficits with indirect but conclusive evidence of dysfunctions of the underlying neural networks. These deficits are present in tasks requiring only maintenance of verbal or visuospatial information. In contrast to a seemingly global working memory deficit, individual analysis revealed differential patterns of working memory impairments in patients with schizophrenia.
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Anselmetti S, Bechi M, Bosia M, Quarticelli C, Ermoli E, Smeraldi E, Cavallaro R. 'Theory' of mind impairment in patients affected by schizophrenia and in their parents. Schizophr Res 2009; 115:278-85. [PMID: 19818586 DOI: 10.1016/j.schres.2009.09.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 09/09/2009] [Accepted: 09/16/2009] [Indexed: 10/20/2022]
Abstract
"Theory of mind" (ToM) is the ability to judge the mental states of the self and others. It is currently considered as a part of the broader concept of social cognition, known to influence the social behaviour of patients affected by schizophrenia. Recently it has been hypothesized that the impairment of ToM is a trait that can be detected both in patients with schizophrenia and in non-psychotic relatives of patients, but it still not clear what the contribution of the familial patterns of cognitive impairment is. The aim of this study is to assess parental impairments of ToM performance considering the effects of the neurocognitive abilities known to be impaired in their first-degree relatives and to influence ToM in schizophrenic patients. Patients, their parents and control trios were assessed with the Wisconsin Card Sorting Test (WCST), the Symbol Coding Task and the ToM Picture Sequencing Task. The ANCOVA analysis on 47 trios including a schizophrenic offspring and 47 healthy trios showed a statistically significant poorer performance of patients and their parents in comparison to control trios at Symbol Coding Task and ToM task. Moreover a regression analysis showed that the neuropsychological abilities tested were significant predictors of ToM performance only in patients. Results confirm a ToM impairment among parents of patients with schizophrenia that is not directly correlated to other aspects of neurocognitive functioning.
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Affiliation(s)
- S Anselmetti
- Department of Clinical Neurosciences, San Raffaele Universitary Scientific Institute Hospital, Via Stamira d'Ancona 20, 20127 Milano, Italy.
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Zilles D, Burke S, Schneider-Axmann T, Falkai P, Gruber O. Diagnosis-specific effect of familial loading on verbal working memory in schizophrenia. Eur Arch Psychiatry Clin Neurosci 2009; 259:309-15. [PMID: 19274424 PMCID: PMC2727368 DOI: 10.1007/s00406-009-0001-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Accepted: 01/29/2009] [Indexed: 01/30/2023]
Abstract
BACKGROUND Working memory disturbances are a frequently replicated finding in schizophrenia and less consistent also in schizoaffective disorder. Working memory dysfunctions have been shown to be heritable and have been proposed to represent a promising endophenotype of schizophrenic psychoses. METHODS In the present study, we investigated the effects of familial loading on performance rates in circuit-specific verbal and visuospatial working memory tasks in matched samples of schizophrenic patients (from multiply affected or uniaffected families), schizoaffective patients (from multiply affected or uniaffected families), and healthy subjects. RESULTS We found a significant interaction effect between familial loading and diagnosis in terms of a diagnosis-specific detrimental effect of familial loading on the performance of schizophrenic (but not schizoaffective) patients in the articulatory rehearsal task. CONCLUSION This finding of a circuit-specific verbal working memory deficit in schizophrenic patients with additional familial loading is consistent with prior studies, which provided evidence for the existence of specific subgroups of schizophrenic patients with selective working memory impairments and for diagnosis-specific dysfunctions of the articulatory rehearsal mechanism in schizophrenic, but not in schizoaffective patients. Together, these findings suggest that the genetic risk for (a subtype of) schizophrenia may be associated with dysfunctions of the brain system, which underlies the articulatory rehearsal mechanism, the probably phylogenetically youngest part of human working memory.
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Affiliation(s)
- David Zilles
- Department of Psychiatry and Psychotherapy, Georg August University, Von-Siebold-Str. 5, 37075 Göttingen, Germany
| | - Sarah Burke
- Department of Psychiatry and Psychotherapy, Georg August University, Von-Siebold-Str. 5, 37075 Göttingen, Germany
| | - Thomas Schneider-Axmann
- Department of Psychiatry and Psychotherapy, Georg August University, Von-Siebold-Str. 5, 37075 Göttingen, Germany
| | - Peter Falkai
- Department of Psychiatry and Psychotherapy, Georg August University, Von-Siebold-Str. 5, 37075 Göttingen, Germany
| | - Oliver Gruber
- Department of Psychiatry and Psychotherapy, Georg August University, Von-Siebold-Str. 5, 37075 Göttingen, Germany
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Gaspar PA, Bustamante ML, Silva H, Aboitiz F. Molecular mechanisms underlying glutamatergic dysfunction in schizophrenia: therapeutic implications. J Neurochem 2009; 111:891-900. [PMID: 19686383 DOI: 10.1111/j.1471-4159.2009.06325.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Early models for the etiology of schizophrenia focused on dopamine neurotransmission because of the powerful anti-psychotic action of dopamine antagonists. Nevertheless, recent evidence increasingly supports a primarily glutamatergic dysfunction in this condition, where dopaminergic disbalance is a secondary effect. A current model for the pathophysiology of schizophrenia involves a dysfunctional mechanism by which the NMDA receptor (NMDAR) hypofunction leads to a dysregulation of GABA fast- spiking interneurons, consequently disinhibiting pyramidal glutamatergic output and disturbing the signal-to-noise ratio. This mechanism might explain better than other models some cognitive deficits observed in this disease, as well as the dopaminergic alterations and therapeutic effect of anti-psychotics. Although the modulation of glutamate activity has, in principle, great therapeutic potential, a side effect of NMDAR overactivation is neurotoxicity, which accelerates neuropathological alterations in this illness. We propose that metabotropic glutamate receptors can have a modulatory effect over the NMDAR and regulate excitotoxity mechanisms. Therefore, in our view metabotropic glutamate receptors constitute a highly promising target for future drug treatment in this disease.
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Affiliation(s)
- Pablo A Gaspar
- Clínica Psiquiátrica Universitaria, Hospital Clínico de la Universidad de Chile, Casilla, Santiago, Chile.
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46
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Abstract
BACKGROUND Memory impairment is being recognized increasingly as an important feature of the neuropsychology of schizophrenia. Dysfunction of working memory, a system for the short-term storage and manipulation of information, may relate to a number of core symptoms of schizophrenia. Many studies have examined working memory function in schizophrenia but a clear understanding of the nature and extent of any deficit has been elusive. METHOD A systematic review and meta-analysis of studies comparing working memory function in subjects with schizophrenia and healthy controls was performed. Following a comprehensive literature search, meta-analyses were conducted on 36 measures of phonological, visuospatial and central executive working memory functioning, encompassing 441 separate results from 187 different studies. RESULTS Statistically significant effect sizes were found for all working memory measures, indicating deficits in schizophrenia groups. Some of these were robust findings in the absence of evidence of significant heterogeneity or publication bias. Meta-regression analyses showed that the working memory deficit was not simply explained by discrepancies in current IQ between schizophrenia and control groups. CONCLUSIONS Large deficits in working memory were demonstrated in schizophrenia groups across all three working memory domains. There were, however, no clear differences across subdomains or between particular working memory tasks. There was substantial heterogeneity across results that could only be partly explained.
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47
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Zanello A, Curtis L, Badan Bâ M, Merlo MCG. Working memory impairments in first-episode psychosis and chronic schizophrenia. Psychiatry Res 2009; 165:10-8. [PMID: 19046607 DOI: 10.1016/j.psychres.2007.10.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Accepted: 10/03/2007] [Indexed: 12/22/2022]
Abstract
Working memory (WM) impairments are core cognitive deficits in patients with schizophrenia linked to prefrontal cortical dysfunctions. Determining the differences between early phases of illness allows a better understanding of its course and constitutes an important guide for treatment. The present cross-sectional study examined differences of working memory functions between 33 first-episode and 29 chronic schizophrenic patients, as well as 64 healthy controls. On the basis of a two-back visual-verbal computerized working memory task, reaction time was slower and accuracy was worse in both patient groups than in controls. Test variables, however, were not significantly different between the patient groups, suggesting stability of the deficits over time. Effect size accuracy variables nevertheless showed larger deficits in chronic patients.
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Affiliation(s)
- Adriano Zanello
- University Hospitals of Geneva, Department of Psychiatry, Division of Adult Psychiatry, Geneva, Switzerland
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48
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Eack SM, Prasad KMR, Montrose DM, Goradia DD, Dworakowski D, Miewald J, Keshavan MS. An integrated psychobiological predictive model of emergent psychopathology among young relatives at risk for schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2008; 32:1873-8. [PMID: 18812206 PMCID: PMC2649961 DOI: 10.1016/j.pnpbp.2008.08.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2008] [Revised: 08/06/2008] [Accepted: 08/27/2008] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Studies of young relatives at elevated risk for schizophrenia have pointed to the importance of a variety of neurobiological, cognitive, and clinical risk factors for the disorder; yet few have employed integrated models to estimate the joint contribution of these factors to heightened schizophrenic risk. We tested the predictive power of an integrated psychobiological model of schizophrenia risk to subsequent psychopathology development among young relatives at risk for the disorder. METHODS Young first (n=66) and second (n=20) degree relatives of schizophrenia probands were followed for an average of 3 (SD=1.13) years to examine their trajectories toward psychopathology development. Neurobiologic, cognitive, and clinical measures were employed in an integrated structural equation model to estimate their contribution to the prospective emergence of psychopathology. RESULTS Results indicated that neurobiological, neurocognitive, and psychosis proneness factors at baseline were all uniquely predictive of subsequent psychopathology development, and that an integrated model of psychopathology development that took into account these factors provided an excellent fit to the observed data. Subsequent classification analyses of model accuracy using likelihood ratios adjusting for the base-rate of psychopathology development in this sample revealed that individuals identified by this model had a 71% chance of developing psychopathology in the future. CONCLUSIONS An integrated model of biobehavioral risk factors may provide a powerful method for predicting psychopathology and schizophrenia risk in at-risk samples. If validated, this model may be useful for early detection and intervention programs. Future research will need to focus particularly on predicting schizophrenia development and refining models to further enhance sensitivity.
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Affiliation(s)
- Shaun M Eack
- Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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Wang Y, Chan RCK, Shi C, Cui J, Deng Y. Prospective memory deficits in subjects with schizophrenia spectrum disorders: a comparison study with schizophrenic subjects, psychometrically defined schizotypal subjects, and healthy controls. Schizophr Res 2008; 106:70-80. [PMID: 17719206 DOI: 10.1016/j.schres.2007.07.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Revised: 07/18/2007] [Accepted: 07/25/2007] [Indexed: 11/27/2022]
Abstract
Memory impairment is one of the core deficits in schizophrenia. This study explored the memory profiles of schizophrenic and psychometrically defined schizotypal subjects. The study participants included 15 patients with schizophrenia, 41 schizotypal subjects, and 20 healthy controls. All of the participants completed verbal and visual memory, working memory, and prospective memory tasks. The results showed that patients with schizophrenia were impaired in all aspects of memory function, whereas the schizotypal subjects tended to show moderate to large impairment effect sizes in prospective memory. It is suggested that prospective memory be considered a potential endophenotype of schizophrenia.
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Affiliation(s)
- Ya Wang
- Department of Psychology, Sun Yat-Sen University, Guangzhou, China; School of Life Science, Sun Yat-Sen University, Guangzhou, China
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50
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Almasy L, Gur RC, Haack K, Cole SA, Calkins ME, Peralta JM, Hare E, Prasad K, Pogue-Geile MF, Nimgaonkar V, Gur RE. A genome screen for quantitative trait loci influencing schizophrenia and neurocognitive phenotypes. Am J Psychiatry 2008; 165:1185-92. [PMID: 18628350 PMCID: PMC2644284 DOI: 10.1176/appi.ajp.2008.07121869] [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: 02/08/2023]
Abstract
OBJECTIVE Deficits in neurocognitive function have been demonstrated in individuals with schizophrenia and in the unaffected family members of these individuals. Genetic studies of such complementary traits, along with traditional analyses of diagnosis, may help to elucidate the biological pathways underlying familial liability to schizophrenia and related disorders. The authors conducted a multiplex, multigenerational family study using a genome-wide screen for schizophrenia and related neurocognitive phenotypes. METHOD Participants were 1) 676 European American individuals from 43 families, ascertained through an individual with schizophrenia, and 2) 236 healthy comparison subjects. Participants were evaluated clinically and examined through the use of a computerized neurocognitive test battery that provided measures of accuracy and speed on the cognitive domains of abstraction and mental flexibility; attention; verbal, face, and spatial memory; language and reasoning; spatial and emotion processing; and sensorimotor dexterity. A genome-wide linkage screen was also performed. Healthy comparison subjects were included in order to obtain normative phenotypic data but were not genotyped. RESULTS Significant evidence for linkage of schizophrenia to chromosome 19q was observed. Analysis of cognitive traits revealed significant linkage to chromosome 5q for the domains of abstraction and mental flexibility. A variety of other neurocognitive traits also showed nominal evidence of linkage to the 5q region. Joint analyses with diagnosis suggested that this quantitative trait locus may also influence schizophrenia. CONCLUSIONS Although chromosome 5 has been implicated in previous linkage studies of schizophrenia, the identification of the chromosome 19 quantitative trait locus is a novel finding. The identification of the chromosome 5 quantitative trait locus through linkage to neurocognitive phenotypes in the present study may inform functional hypotheses pertaining to how genotypes are connected to disease.
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Affiliation(s)
- Laura Almasy
- Department of Genetics, Southwest Foundation for Biomedical Research, P.O. Box 760549, San Antonio, TX 78249-0549, USA.
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