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Peterson BS, Kaur T, Sawardekar S, Colibazzi T, Hao X, Wexler BE, Bansal R. Aberrant hippocampus and amygdala morphology associated with cognitive deficits in schizophrenia. Front Cell Neurosci 2023; 17:1126577. [PMID: 36909281 PMCID: PMC9996667 DOI: 10.3389/fncel.2023.1126577] [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] [Received: 12/18/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Background Working memory deficits are thought to be a primary disturbance in schizophrenia. We aimed to identify differences in morphology of the hippocampus and amygdala in patients with schizophrenia compared with healthy controls (HCs), and in patients who were either neuropsychologically near normal (NPNN) or neuropsychologically impaired (NPI). Morphological disturbances in the same subfields of the hippocampus and amygdala, but of greater magnitude in those with NPI, would strengthen evidence for the centrality of these limbic regions and working memory deficits in the pathogenesis of schizophrenia. Methods We acquired anatomical MRIs in 69 patients with schizophrenia (18 NPNN, 46 NPI) and 63 age-matched HC participants. We compared groups in hippocampus and amygdala surface morphologies and correlated morphological measures with clinical symptoms and working memory scores. Results Schizophrenia was associated with inward deformations of the head and tail of the hippocampus, protrusion of the hippocampal body, and widespread inward deformations of the amygdala. In the same regions where we detected the effects of schizophrenia, morphological measures correlated positively with the severity of symptoms and inversely with working memory performance. Patients with NPI displayed a similar pattern of anatomical abnormality compared to patients with NPNN. Conclusion Our findings indicate that anatomical abnormalities of the hippocampus relate to working memory performance and clinical symptoms in persons with schizophrenia. Moreover, NPNN and NPI patients may lie on a continuum of severity, both in terms of working memory abilities and altered brain structure, with NPI patients being more severe than NPNN patients in both domains.
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Affiliation(s)
- Bradley S. Peterson
- Children’s Hospital Los Angeles, Department of Psychiatry at the Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- *Correspondence: Bradley S. Peterson,
| | - Tejal Kaur
- Department of Psychiatry, Columbia College of Physicians and Surgeons, New York, NY, United States
| | - Siddhant Sawardekar
- Children’s Hospital Los Angeles, Department of Psychiatry at the Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Tiziano Colibazzi
- Department of Psychiatry, Columbia College of Physicians and Surgeons, New York, NY, United States
| | - Xuejun Hao
- Department of Psychiatry, Columbia College of Physicians and Surgeons, New York, NY, United States
| | - Bruce E. Wexler
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States
| | - Ravi Bansal
- Children’s Hospital Los Angeles, Department of Psychiatry at the Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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Karpova N, Zhang D, Beckwith AM, Bennett DS, Lewis M. Prenatal drug exposure and executive function in early adolescence. Neurotoxicol Teratol 2021; 88:107036. [PMID: 34648914 DOI: 10.1016/j.ntt.2021.107036] [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: 12/16/2020] [Revised: 09/15/2021] [Accepted: 09/30/2021] [Indexed: 12/31/2022]
Abstract
PURPOSE Study of the relationship between prenatal cocaine exposure (PCE) and executive function (EF) has yielded inconsistent results. The purpose of the current study is to examine whether PCE, biological sex, environmental risk, and their interaction predicted EF in early adolescence. METHODS 135 12-year-old adolescents (40.7% with PCE), who were followed prospectively from birth, attempted up to 8 Tower of Hanoi (ToH) puzzle trials of increasing complexity. The number of correctly completed puzzles served as the main outcome measure. Survival analysis was used to examine predictors of the number of successfully completed trials. RESULTS As trial difficulty increased, fewer adolescents were able to solve the TOH puzzle. Adolescents from high risk environments and with either prenatal alcohol or prenatal cannabis exposure completed fewer puzzles (p < .05). In addition, a hypothesized 3-way interaction of PCE x sex x environmental risk was found such that cocaine-exposed males with high environmental risk had the worst performance (p < .01). CONCLUSIONS The current findings are consistent with prior research indicating that males with PCE may be at particular risk of poorer functioning and highlight the potential importance of examining adolescent's sex and environmental risk as moderators of PCE effects.
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Affiliation(s)
- Natalia Karpova
- Rutgers Robert Wood Johnson Medical School, Institute for the Study of Child Development, Department of Pediatrics, 89 French Street, New Brunswick, NJ 08901, United States.
| | - Dake Zhang
- Rutgers the State University of New Jersey, Department of Educational Psychology, 10 Seminary Place, New Brunswick, NJ 08901, United States.
| | - Anna Malia Beckwith
- Children's Specialized Hospital, Rutgers Robert Wood Johnson Medical School, Department of Pediatrics, 150 New Providence Rd, Mountainside, NJ 07092, United States.
| | - David S Bennett
- Drexel University, GLAD Program, 4700 Wissahickon Avenue, Philadelphia, PA 19144, United States.
| | - Michael Lewis
- Rutgers Robert Wood Johnson Medical School, Institute for the Study of Child Development, 89 French Street, New Brunswick, NJ 08901, United States.
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Hu H, Wang X, Li C, Li Y, Hao J, Zhou Y, Yang X, Chen P, Shen X, Zhang S. Loss of Dysbindin Implicates Synaptic Vesicle Replenishment Dysregulation as a Potential Pathogenic Mechanism in Schizophrenia. Neuroscience 2020; 452:138-152. [PMID: 33186610 DOI: 10.1016/j.neuroscience.2020.10.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 11/18/2022]
Abstract
The schizophrenia-susceptibility gene, dystrobrevin-binding protein 1 (DTNBP1), encodes the dysbindin protein and mediates neurotransmission and neurodevelopment in normal subjects. Functional studies show that DTNBP1 loss may cause deficient presynaptic vesicle transmission, which is related to multiple psychiatric disorders. However, the functional mechanism of dysbindin-mediated synaptic vesicle transmission has not been investigated systematically. In this study, we performed electrophysiological recordings in calyx of Held synapses. We found that excitatory postsynaptic current (EPSC) and miniature EPSC (mEPSC) amplitudes were unchanged in dysbindin-deficient synapses, but readily releasable pool (RRP) size and calcium dependent vesicle replenishment were affected during high-frequency stimulation. Moreover, dysbindin loss accompanied slightly decreases in Munc18-1 and snapin expression levels, which are associated with vesicle priming and synaptic homeostasis under high-frequency stimulation. Together, we inferred that dysbindin directly interacts with Munc18-1 and snapin to mediate calcium dependent RRP replenishment. Dysbindin loss may lead to RRP replenishment dysregulation during high-frequency stimulation, potentially causing cognitive impairment in schizophrenia.
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Affiliation(s)
- Han Hu
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuefeng Wang
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao Li
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Li
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junfeng Hao
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuanli Zhou
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaopeng Yang
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Peihua Chen
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, CAS, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen 518055, China.
| | - Xuefeng Shen
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, CAS, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen 518055, China.
| | - Shuli Zhang
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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4
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Chen YH, Howell B, Edgar JC, Huang M, Kochunov P, Hunter MA, Wootton C, Lu BY, Bustillo J, Sadek JR, Miller GA, Cañive JM. Associations and Heritability of Auditory Encoding, Gray Matter, and Attention in Schizophrenia. Schizophr Bull 2019; 45:859-870. [PMID: 30099543 PMCID: PMC6581123 DOI: 10.1093/schbul/sby111] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Auditory encoding abnormalities, gray-matter loss, and cognitive deficits are all candidate schizophrenia (SZ) endophenotypes. This study evaluated associations between and heritability of auditory network attributes (function and structure) and attention in healthy controls (HC), SZ patients, and unaffected relatives (UR). METHODS Whole-brain maps of M100 auditory activity from magnetoencephalography recordings, cortical thickness (CT), and a measure of attention were obtained from 70 HC, 69 SZ patients, and 35 UR. Heritability estimates (h2r) were obtained for M100, CT at each group-difference region, and the attention measure. RESULTS SZ patients had weaker bilateral superior temporal gyrus (STG) M100 responses than HC and a weaker right frontal M100 response than UR. Abnormally large M100 responses in left superior frontal gyrus were observed in UR and SZ patients. SZ patients showed smaller CT in bilateral STG and right frontal regions. Interrelatedness between 3 putative SZ endophenotypes was demonstrated, although in the left STG the M100 and CT function-structure associations observed in HC and UR were absent in SZ patients. Heritability analyses also showed that right frontal M100 and bilateral STG CT measures are significantly heritable. CONCLUSIONS Present findings indicated that the 3 SZ endophenotypes examined are not isolated markers of pathology but instead are connected. The pattern of auditory encoding group differences and the pattern of brain function-structure associations differ as a function of brain region, indicating the need for regional specificity when studying these endophenotypes, and with the presence of left STG function-structure associations in HC and UR but not in SZ perhaps reflecting disease-associated damage to gray matter that disrupts function-structure relationships in SZ.
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Affiliation(s)
- Yu-Han Chen
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children’s Hospital of Philadelphia, Philadelphia, PA,To whom correspondence should be addressed; Department of Radiology, The Children’s Hospital of Philadelphia, Seashore House 1F Room 116B, Philadelphia, PA 19104, USA; tel: +1(267)426-0959, fax: +1(267)425-2465, e-mail:
| | - Breannan Howell
- Department of Psychology, The University of New Mexico, Albuquerque, NM,Department of Psychiatry and Behavioral Sciences, Center for Psychiatric Research, The University of New Mexico, Albuquerque, NM
| | - J Christopher Edgar
- Department of Radiology, Lurie Family Foundations MEG Imaging Center, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Mingxiong Huang
- Department of Radiology, University of California, San Diego, San Diego, CA,Department of Radiology, VA San Diego Healthcare System, US Department of Veterans Affairs, San Diego, CA
| | - Peter Kochunov
- Maryland Psychiatric Research Center, The University of Maryland, Baltimore, MD
| | - Michael A Hunter
- Department of Psychology, The University of New Mexico, Albuquerque, NM,Department of Psychiatry and Behavioral Sciences, Center for Psychiatric Research, The University of New Mexico, Albuquerque, NM
| | - Cassandra Wootton
- Department of Psychiatry and Behavioral Sciences, Center for Psychiatric Research, The University of New Mexico, Albuquerque, NM
| | - Brett Y Lu
- Department of Psychiatry, University of Hawaii at Manoa, Honolulu, HI
| | - Juan Bustillo
- Department of Psychiatry and Behavioral Sciences, Center for Psychiatric Research, The University of New Mexico, Albuquerque, NM
| | - Joseph R Sadek
- Psychiatry Research, New Mexico VA Health Care System, Raymond G. Murphy VA Medical Center, US Department of Veterans Affairs, Albuquerque, NM
| | - Gregory A Miller
- Department of Psychology, University of California, Los Angeles, CA,Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA
| | - José M Cañive
- Department of Psychiatry and Behavioral Sciences, Center for Psychiatric Research, The University of New Mexico, Albuquerque, NM,Psychiatry Research, New Mexico VA Health Care System, Raymond G. Murphy VA Medical Center, US Department of Veterans Affairs, Albuquerque, NM
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Kim YK, Na KS. Neuroprotection in Schizophrenia and Its Therapeutic Implications. Psychiatry Investig 2017; 14:383-391. [PMID: 28845163 PMCID: PMC5561394 DOI: 10.4306/pi.2017.14.4.383] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 07/04/2016] [Accepted: 07/06/2016] [Indexed: 12/21/2022] Open
Abstract
Schizophrenia is a chronic and debilitating mental disorder. The persisting negative and cognitive symptoms that are unresponsive to pharmacotherapy reveal the impairment of neuroprotective aspects of schizophrenia. In this review, of the several neuroprotective factors, we mainly focused on neuroinflammation, neurogenesis, and oxidative stress. We conducted a narrative and selective review. Neuroinflammation is mainly mediated by pro-inflammatory cytokines and microglia. Unlike peripheral inflammatory responses, neuroinflammation has a role in various neuronal activities such as neurotransmission neurogenesis. The cross-talk between neuroinflammation and neurogenesis usually has beneficial effects in the CNS under physiological conditions. However, uncontrolled and chronic neuroinflammation exert detrimental effects such as neuronal loss, inhibited neurogenesis, and excessive oxidative stress. Neurogenesis is also a major component of neuroprotection. Adult neurogenesis mainly occurs in the hippocampal region, which has an important role in memory formation and processing. Impaired neurogenesis and an ineffective response to antipsychotics may be thought to indicate a deteriorating course of schizophrenia. Oxidative stress and excessive dopaminergic neurotransmission may create a vicious cycle and consequently disturb NMDA receptor-mediated glutamatergic neurotransmission. Based on the current evidences, several neuroprotective therapeutic approaches have been reported to be efficacious for improving psychopathology, but further longitudinal and large-sample based studies are needed.
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Affiliation(s)
- Yong-Ku Kim
- Department of Psychiatry, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Kyoung-Sae Na
- Department of Psychiatry, Gachon University Gil Medical Center, Incheon, Republic of Korea
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Kim YK, Choi J, Park SC. A Novel Bio-Psychosocial-Behavioral Treatment Model in Schizophrenia. Int J Mol Sci 2017; 18:ijms18040734. [PMID: 28358303 PMCID: PMC5412320 DOI: 10.3390/ijms18040734] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/25/2017] [Accepted: 03/26/2017] [Indexed: 12/21/2022] Open
Abstract
Despite the substantial burden of illness in schizophrenia, there has been a discrepancy between the beneficial effects of an increased use of antipsychotic medications and achieving limited recovery or remission. Because the focus of the most common antipsychotic medications is on dopamine, which is associated with positive symptoms, there is an unmet need for patients with negative symptoms. Since cognitive and negative symptoms rather than positive symptoms are more closely associated with psychosocial impairments in patients with schizophrenia, the non-dopaminergic systems including glutamate and γ-aminobutyric acid (GABA) of the prefrontal cortex should be of concern as well. The balance of excitation and inhibition has been associated with epigenetic modifications and thus can be analyzed in terms of a neurodevelopmental and neural circuitry perspective. Hence, a novel bio-psychosocial-behavioral model for the treatment of schizophrenia is needed to account for the non-dopaminergic systems involved in schizophrenia, rather than dopaminergic mechanisms. This model can be understood from the viewpoint of neurodevelopment and neural circuitry and should include the staging care, personalized care, preventive care, reducing the cognitive deficits, and reducing stigma. Thomas R. Insel proposed this as a goal for schizophrenia treatment to be achieved by 2030.
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Affiliation(s)
- Yong-Ku Kim
- Department of Psychiatry, Korea University College of Medicine, Seoul 02841, Korea.
| | - Joonho Choi
- Department of Psychiatry, Hanyang University Guri Hospital, Guri 11923, Korea.
| | - Seon-Cheol Park
- Department of Psychiatry, Inje University College of Medicine and Haeundae Paik Hospital, Busan 48108, Korea.
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7
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Neural correlates of executive dysfunction in schizophrenia: failure to modulate brain activity with task demands. Neuroreport 2015; 25:1308-15. [PMID: 25275638 DOI: 10.1097/wnr.0000000000000264] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In schizophrenia, executive functions are impaired and are associated with altered activation of prefrontal areas. We used H2[15]O PET to examine patients with schizophrenia and matched controls on a random number generation (RNG) task and a control counting (COUNT) task. To assess the effects of increasing task demand, both tasks were performed at three different rates (intervals 1, 2 or 3 s). Both groups showed a significant increase in the nonrandomness of responses at faster rates of RNG. Despite similar performances, patients but not controls showed higher activation of the right dorsolateral prefrontal cortex (DLPFC) and atypically reduced activation of the right anterior cingulate gyrus and the right medial frontal gyrus in RNG compared with COUNT, whereas only for controls, activation of the left DLPFC was increased and activation of the right superior temporal gyrus and the right superior frontal gyrus was reduced in the same comparison. Whereas for the controls several cortical areas including the bilateral superior temporal gyrus and the bilateral DLPFC, together with the right cerebellum, showed significant changes in regional cerebral blood flow with faster or slower rates, patients with schizophrenia showed rate-dependent changes only in the left cerebellum. In conclusion, the patients' failure to modulate cortical activation with changing demands of rate, particularly in prefrontal areas and in the cerebellum, and even when performance is similar to that in healthy controls, is a characteristic of their abnormal pattern of executive processing.
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8
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Zhou Y, Wang Z, Zuo XN, Zhang H, Wang Y, Jiang T, Liu Z. Hyper-coupling between working memory task-evoked activations and amplitude of spontaneous fluctuations in first-episode schizophrenia. Schizophr Res 2014; 159:80-9. [PMID: 25132644 DOI: 10.1016/j.schres.2014.07.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 04/16/2014] [Accepted: 07/20/2014] [Indexed: 12/15/2022]
Abstract
Working memory (WM) deficit is an important component of impaired cognition in schizophrenia. However, between-studies inconsistencies as to the specific functional substrate imply that inter-individual variability (IIV) in the WM performance is associated with IIV in brain activity in schizophrenia. To examine the neural substrate of this WM IIV, we studied whether the neural mechanisms that underlie individual differences in WM capacity are the same in schizophrenia patients and healthy people. We correlated the IIV of the task-evoked brain activity and task performance during an n-back WM task with the IIV of the moment-to-moment variability in intrinsic resting-state activity, as measured by the amplitude of low-frequency fluctuations (ALFFs) and further compared this relationship between 17 patients with first-episode schizophrenia (FES) and 18 healthy controls. Between-group comparisons of the correlation patterns indicated aberrant ALFF-WM activation correlations and ALFF-WM performance correlations in the FES patients, but no significant changes were detected in any single measurement of these three characteristics. Specifically, we found increased positive ALFF-WM activation correlations in the bilateral lateral prefrontal cortices, posterior parietal cortices and fusiform gyri in the FES patients. We also observed significant increases in positive ALFF-WM performance correlations in the bilateral ventromedial prefrontal cortices in the FES patients. This hyper-coupling between the ALFF and fMRI measures during a WM task may indicate that it was difficult for the patients to detach themselves from one state to transition to another and suggests that the inefficient cortical function in schizophrenia stems from the intrinsic functional architecture of the brain.
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Affiliation(s)
- Yuan Zhou
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zheng Wang
- Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Xi-Nian Zuo
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huiran Zhang
- Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Yun Wang
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tianzi Jiang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China; National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhening Liu
- Institute of Mental Health, Second Xiangya Hospital, Central South University, Changsha 410011, China.
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9
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Kaller CP, Loosli SV, Rahm B, Gössel A, Schieting S, Hornig T, Hennig J, Tebartz van Elst L, Weiller C, Katzev M. Working memory in schizophrenia: behavioral and neural evidence for reduced susceptibility to item-specific proactive interference. Biol Psychiatry 2014; 76:486-94. [PMID: 24768119 DOI: 10.1016/j.biopsych.2014.03.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 03/07/2014] [Accepted: 03/11/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Susceptibility to item-specific proactive interference (PI) contributes to interindividual differences in working memory (WM) capacity and complex cognition relying on WM. Although WM deficits are a well-recognized impairment in schizophrenia, the underlying pathophysiological effects on specific WM control functions, such as the ability to resist item-specific PI, remain unknown. Moreover, opposing hypotheses on increased versus reduced PI susceptibility in schizophrenia are both justifiable by the extant literature. METHODS To provide first insights into the behavioral and neural correlates of PI-related WM control in schizophrenia, a functional magnetic resonance imaging experiment was conducted in a sample of 20 patients and 20 well-matched control subjects. Demands on item-specific PI were experimentally manipulated in a recent-probes task (three runs, 64 trials each) requiring subjects to encode and maintain a set of four target items per trial. RESULTS Compared with healthy control subjects, schizophrenia patients showed a significantly reduced PI susceptibility in both accuracy and latency measures. Notably, reduced PI susceptibility in schizophrenia was not associated with overall WM impairments and thus constituted an independent phenomenon. In addition, PI-related activations in inferior frontal gyrus and anterior insula, typically assumed to support PI resistance, were reduced in schizophrenia, thus ruling out increased neural efforts as a potential cause of the patients' reduced PI susceptibility. CONCLUSIONS The present study provides first evidence for a diminished vulnerability of schizophrenia patients to item-specific PI, which is presumably a consequence of the patients' more efficient clearing of previously relevant WM traces and the accordingly reduced likelihood for item-specific PI to occur.
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Affiliation(s)
- Christoph P Kaller
- Department of Neurology, University Medical Center Freiburg, Freiburg; Freiburg Brain Imaging Center, University of Freiburg, Freiburg; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, Germany.
| | - Sandra V Loosli
- Department of Neurology, University Medical Center Freiburg, Freiburg; Freiburg Brain Imaging Center, University of Freiburg, Freiburg; Biological and Personality Psychology, Department of Psychology, University of Freiburg, Freiburg
| | - Benjamin Rahm
- Medical Psychology and Medical Sociology, University Medical Center Mainz, Mainz
| | - Astrid Gössel
- Department of Neurology, University Medical Center Freiburg, Freiburg; Freiburg Brain Imaging Center, University of Freiburg, Freiburg
| | | | - Tobias Hornig
- Department of Neurology, University Medical Center Freiburg, Freiburg; Department of Psychiatry , University Medical Center Freiburg, Freiburg
| | - Jürgen Hennig
- Freiburg Brain Imaging Center, University of Freiburg, Freiburg; Medical Physics, Department of Radiology, University Medical Center Freiburg, Freiburg; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, Germany
| | - Ludger Tebartz van Elst
- Freiburg Brain Imaging Center, University of Freiburg, Freiburg; Department of Psychiatry , University Medical Center Freiburg, Freiburg
| | - Cornelius Weiller
- Department of Neurology, University Medical Center Freiburg, Freiburg; Freiburg Brain Imaging Center, University of Freiburg, Freiburg; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, Germany
| | - Michael Katzev
- Department of Neurology, University Medical Center Freiburg, Freiburg; Freiburg Brain Imaging Center, University of Freiburg, Freiburg
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10
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Wongupparaj P, Kumari V, Morris RG. Executive function processes mediate the impact of working memory impairment on intelligence in schizophrenia. Eur Psychiatry 2014; 30:1-7. [PMID: 25169445 DOI: 10.1016/j.eurpsy.2014.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/03/2014] [Accepted: 06/04/2014] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE The study investigated working memory, executive functions (conceptualized as response inhibition, updating, and shifting), and intelligence in schizophrenia, using structural equation modelling to determine the relationship between working memory and intelligence, testing whether specific executive functions act as a mediator for the association. METHOD One hundred and twenty-five individuals diagnosed with schizophrenia and 64 healthy participants were included in the study, tested using measures of working memory, intelligence and executive functioning. Structural equation modelling (SEM) was used to estimate direct and indirect associations between main measures. RESULTS The schizophrenia group had significantly lower working memory, executive function and intelligence than the healthy group. The relationship between working memory and intelligence was significantly mediated by inhibition, updating and shifting functions. CONCLUSION The study indicates a mediating role of executive functions in determining the association between working memory and intellectual function in schizophrenia. It is further proposed that in people with schizophrenia, cognitive remediation approaches targeting working memory through executive functioning may in turn improve intellectual function generally.
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Affiliation(s)
- P Wongupparaj
- Department of Psychology, P078, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK.
| | - V Kumari
- Department of Psychology, P078, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK; NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation Trust, London, UK
| | - R G Morris
- Department of Psychology, P078, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK
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11
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Unschuld PG, Buchholz AS, Varvaris M, van Zijl PCM, Ross CA, Pekar JJ, Hock C, Sweeney JA, Tamminga CA, Keshavan MS, Pearlson GD, Thaker GK, Schretlen DJ. Prefrontal brain network connectivity indicates degree of both schizophrenia risk and cognitive dysfunction. Schizophr Bull 2014; 40:653-64. [PMID: 23778975 PMCID: PMC3984516 DOI: 10.1093/schbul/sbt077] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Cognitive dysfunction is a core feature of schizophrenia, and persons at risk for schizophrenia may show subtle deficits in attention and working memory. In this study, we investigated the relationship between integrity of functional brain networks and performance in attention and working memory tasks as well as schizophrenia risk. METHODS A total of 235 adults representing 3 levels of risk (102 outpatients with schizophrenia, 70 unaffected first-degree relatives of persons with schizophrenia, and 63 unrelated healthy controls [HCs]) completed resting-state functional magnetic resonance imaging and a battery of attention and working memory tasks (Brief Test of Attention, Hopkins Verbal Learning Test, and Brief Visuospatial Memory Test) on the same day. Functional networks were defined based on coupling with seeds in the dorsal anterior cingulate cortex, dorsolateral prefrontal cortex (DLPFC), medial prefrontal cortex (MPFC), and primary visual cortex. Networks were then dissected into regional clusters of connectivity that were used to generate individual interaction matrices representing functional connectivity within each network. RESULTS Both patients with schizophrenia and their first-degree relatives showed cognitive dysfunction compared with HCs. First canonicals indicated an inverse relationship between cognitive performance and connectivity within the DLPFC and MPFC networks. Multivariate analysis of variance revealed multivariate main effects of higher schizophrenia risk status on increased connectivity within the DLPFC and MPFC networks. CONCLUSIONS These data suggest that excessive connectivity within brain networks coupled to the DLPFC and MPFC, respectively, accompany cognitive deficits in persons at risk for schizophrenia. This might reflect compensatory reactions in neural systems required for cognitive processing of attention and working memory tasks to brain changes associated with schizophrenia.
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Affiliation(s)
- Paul G. Unschuld
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD;,Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich, Zürich, Switzerland;,*To whom correspondence should be addressed; Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich, Minervastrasse 145, CH-8032 Zürich, Switzerland; tel: +41-44-3891-453, fax: +41-44-3891-447, e-mail:
| | - Alison S. Buchholz
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Mark Varvaris
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Peter C. M. van Zijl
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD;,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD
| | - Christopher A. Ross
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD;,Department of Neurology and,Department of Neuroscience and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - James J. Pekar
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD;,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD
| | - Christoph Hock
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich, Zürich, Switzerland
| | - John A. Sweeney
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Carol A. Tamminga
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Matcheri S. Keshavan
- Department of Psychiatry, Beth Israel Deaconess Medical Center (BIDMC), Harvard Medical School, Boston, MA
| | - Godfrey D. Pearlson
- Olin Neuropsychiatry Research Center, Hartford Hospital, Hartford, CT;,Department of Psychiatry and Neurobiology, Yale University School of Medicine, New Haven, CT
| | - Gunvant K. Thaker
- Department of Psychiatry, University of Maryland, School of Medicine, Baltimore, MD
| | - David J. Schretlen
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD;,The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD
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12
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Thormodsen R, Jensen J, Holmèn A, Juuhl-Langseth M, Emblem KE, Andreassen OA, Rund BR. Prefrontal hyperactivation during a working memory task in early-onset schizophrenia spectrum disorders: an fMRI study. Psychiatry Res 2011; 194:257-262. [PMID: 22079661 DOI: 10.1016/j.pscychresns.2011.05.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 05/16/2011] [Accepted: 05/25/2011] [Indexed: 10/15/2022]
Abstract
Working memory (WM) dysfunction is increasingly recognized as a core feature of schizophrenia, but few studies have investigated prefrontal activation during WM tasks in early-onset schizophrenia spectrum disorder (EOS). Our aim was to explore prefrontal activation during a WM-task in EOS patients compared to healthy controls using functional magnetic resonance imaging (fMRI). Fifteen patients with EOS and 15 matched healthy controls performed a 0-back and a 2-back task while fMRI data were acquired. Results indicated that even though performance between patients and controls was comparable on both tasks, there was a hyperactivation in patients' ventrolateral prefrontal cortex (VLPFC) during the 2-back task compared to healthy controls. This pattern of activation suggests that, in patients with EOS, the VLPFC compensated in order to match performance of the controls. The activations in the EOS group may reflect the use of a compensatory, cognitive strategy while solving WM-tasks.
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Affiliation(s)
- Rune Thormodsen
- Vestre Viken Hospital Trust, 1309 Rud, Oslo, Norway; Department of Psychology, University of Oslo, Norway.
| | - Jimmy Jensen
- Department of Psychiatry, Oslo University Hospital, Norway; Institute of Psychiatry, University of Oslo, Norway; Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin, Berlin, Germany.
| | - Aina Holmèn
- Department of Psychology, University of Oslo, Norway; Akershus University Hospital, Mental Health Division, Norway.
| | - Monica Juuhl-Langseth
- Department of Psychology, University of Oslo, Norway; Research unit Sogn, Oslo University Hospital, Norway.
| | - Kyrre Eeg Emblem
- The Interventional Centre, Rikshospitalet, Oslo University Hospital, Norway; Department of Medical Physics, Rikshospitalet, Oslo University Hospital, Norway.
| | - Ole Andreas Andreassen
- Department of Psychiatry, Oslo University Hospital, Norway; Institute of Psychiatry, University of Oslo, Norway.
| | - Bjørn Rishovd Rund
- Vestre Viken Hospital Trust, 1309 Rud, Oslo, Norway; Department of Psychology, University of Oslo, Norway.
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13
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Lis S, Apostolopoulos J, Kirsch P, Gallhofer B. Sensory and motor encoding strategies in n-back tasks: a simulation of schizophrenic working memory deficits in healthy subjects. Neuropsychobiology 2011; 63:137-46. [PMID: 21228605 DOI: 10.1159/000319459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 07/15/2010] [Indexed: 11/19/2022]
Abstract
AIMS Different patterns of intact and disturbed working memory function can be observed in schizophrenic patients depending on the type of n-back task. We investigated whether these patterns can be induced in healthy subjects by experimentally preventing a motor encoding strategy. METHODS Thirty-two healthy subjects were asked to solve 2 types of n-back task. In the continuous matching task, the subjects had to compare the present stimulus with the one occurring n stimuli back. In the continuous delayed response task (CDRT), the subjects had to select a response depending on the stimulus n stimuli back. Both types of n-back task are assumed to differ with respect to the encoding strategies that can be used to solve the tasks. The use of a motor strategy was prevented by a random arrangement of the target buttons. RESULTS When the position of the target buttons was predictable, CDRT was solved faster and with higher accuracy than the continuous matching task. However, CDRT was solved more slowly and less accurately when the arrangement of the target buttons varied between the trials. This resulted in a comparable performance in both types of the n-back task. CONCLUSIONS The behavioural alteration in schizophrenic patients in n-back tasks can be induced in healthy subjects by experimentally preventing the use of a motor encoding strategy.
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Affiliation(s)
- Stefanie Lis
- Centre for Psychiatry, Justus Liebig University Giessen, Giessen, Germany.
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14
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Mouchet-Mages S, Rodrigo S, Cachia A, Mouaffak F, Olie JP, Meder JF, Oppenheim C, Krebs MO. Correlations of cerebello-thalamo-prefrontal structure and neurological soft signs in patients with first-episode psychosis. Acta Psychiatr Scand 2011; 123:451-8. [PMID: 21219267 DOI: 10.1111/j.1600-0447.2010.01667.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE This study aimed at determining brain structural imaging correlates of neurological soft signs (NSS) in patients suffering from a first-episode psychosis. METHOD Fifty-two patients with a DSMIV diagnosis of first-episode psychosis (schizophrenia or schizophrenia spectrum disorder) were consecutively included. Subjects were assessed using a standardized neurological examination for motor coordination, motor integration and sensory integration. Anatomical magnetic resonance images (MRI) were analysed in the whole brain using optimized voxel-based morphometry. RESULTS Neurological soft signs (NSS) total score (P-corrected = 0.013) and motor integration subscore (P-corrected = 0.035) were found to negatively correlate with grey matter structure of the dorsolateral prefrontal cortices. Motor coordination subscore was positively correlated with grey matter structure of the thalami (P-corrected = 0.002) and negatively with white matter structure of the cerebellum (P-corrected = 0.034). The addition of age and gender as covariate yielded similar results. We did not find any correlation between neither sensory integration subscore and grey matter structure nor NSS total score, motor integration subscore and voxel-based morphometry (VBM) white matter structure. CONCLUSION Structural alteration in the cerebello-thalamo-prefrontal network is associated with neurological soft signs in schizophrenia, a candidate network for 'cognitive dysmetria'.
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Affiliation(s)
- S Mouchet-Mages
- INSERM, U, Laboratory of Pathophysiology of Psychiatric Diseases, Faculty of Medecine Paris Descartes, Service Hospitalo Universitaire, France
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15
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Nadel L, Hardt O. Update on memory systems and processes. Neuropsychopharmacology 2011; 36:251-73. [PMID: 20861829 PMCID: PMC3055510 DOI: 10.1038/npp.2010.169] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 08/11/2010] [Accepted: 08/23/2010] [Indexed: 12/29/2022]
Abstract
Ideas about how the brain organizes learning and memory have been evolving in recent years, with potentially important ramifications. We review traditional thinking about learning and memory and consider more closely emerging trends from both human and animal research that could lead to profound shifts in how we understand the neural basis of memory.
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Affiliation(s)
- Lynn Nadel
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA.
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16
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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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17
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Distinct contribution of working memory and social comprehension failures in neuropsychological impairment in schizophrenia. J Nerv Ment Dis 2010; 198:206-12. [PMID: 20215998 DOI: 10.1097/nmd.0b013e3181d14143] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Neuropsychological impairment represents a core characteristic of schizophrenia, but its underlying components have yet to be clearly established. Using a comprehensive battery of standardized measures of intelligence, declarative episodic memory, and executive function, we hypothesized that the variance in neuropsychological performance in schizophrenia may reflect at least 2 distinct sources related to failures of (a) the central executive division of working memory and (b) social comprehension. In comparison to age-matched controls, patients with schizophrenia showed not only overall reduced scores on Wechsler intelligence and memory scales and Wisconsin Card Sorting Test (WCST) of executive function, but they also demonstrated different patterns of performance for each of these tests. Hierarchical regression revealed executive attentional control, measured by Trails B performance speed, and social comprehension, measured by Wechsler IQ Comprehension and Picture Arrangement subtests, each accounted for a unique and specific proportion of variance in test scores for the patient group, even when controlling for general intelligence. Failures in social comprehension and executive attentional control may account for distinct sources of variance in the neuropsychological impairment of schizophrenia.
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18
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19
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Kim DI, Manoach DS, Mathalon DH, Turner JA, Mannell M, Brown GG, Ford JM, Gollub RL, White T, Wible C, Belger A, Bockholt HJ, Clark VP, Lauriello J, O'Leary D, Mueller BA, Lim KO, Andreasen N, Potkin SG, Calhoun VD. Dysregulation of working memory and default-mode networks in schizophrenia using independent component analysis, an fBIRN and MCIC study. Hum Brain Mapp 2010; 30:3795-811. [PMID: 19434601 DOI: 10.1002/hbm.20807] [Citation(s) in RCA: 201] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Deficits in working memory (WM) are a consistent neurocognitive marker for schizophrenia. Previous studies have suggested that WM is the product of coordinated activity in distributed functionally connected brain regions. Independent component analysis (ICA) is a data-driven approach that can identify temporally coherent networks that underlie fMRI activity. We applied ICA to an fMRI dataset for 115 patients with chronic schizophrenia and 130 healthy controls by performing the Sternberg Item Recognition Paradigm. Here, we describe the first results using ICA to identify differences in the function of WM networks in schizophrenia compared to controls. ICA revealed six networks that showed significant differences between patients with schizophrenia and healthy controls. Four of these networks were negatively task-correlated and showed deactivation across the posterior cingulate, precuneus, medial prefrontal cortex, anterior cingulate, inferior parietal lobules, and parahippocampus. These networks comprise brain regions known as the default-mode network (DMN), a well-characterized set of regions shown to be active during internal modes of cognition and implicated in schizophrenia. Two networks were positively task-correlated, with one network engaging WM regions such as bilateral DLPFC and inferior parietal lobules while the other network engaged primarily the cerebellum. Our results suggest that DLPFC dysfunction in schizophrenia might be lateralized to the left and intrinsically tied to other regions such as the inferior parietal lobule and cingulate gyrus. Furthermore, we found that DMN dysfunction in schizophrenia exists across multiple subnetworks of the DMN and that these subnetworks are individually relevant to the pathophysiology of schizophrenia. In summary, this large multisite study identified multiple temporally coherent networks, which are aberrant in schizophrenia versus healthy controls and suggests that both task-correlated and task-anticorrelated networks may serve as potential biomarkers.
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Affiliation(s)
- Dae Il Kim
- The Mind Research Network, Albuquerque, New Mexico 87131, USA.
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20
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Abstract
Impaired cognitive functioning, including deficits in working memory, is considered to be a core and disabling feature of schizophrenia that is difficult to treat. Deficits in working memory in schizophrenia are attributable, at least in part, to specific pathological alterations in the neuronal circuitry of the dorsolateral prefrontal cortex that involve, but are not restricted to, disturbances in glutamate, GABA, and dopamine neurotransmission. Cannabis use provides an example of an environmental exposure that may have a deleterious impact on these neurotransmitter systems and thereby contribute to worsening of cognitive functioning in schizophrenia. Increasing knowledge of the nature of the molecular alterations in these cortical circuits may lead to the development of new pathophysiologically informed treatment options for cognitive deficits in schizophrenia.
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Affiliation(s)
- David W Volk
- Department of Psychiatry, University of Pittsburgh, 3811 O'Hara Street, BST W1653, Pittsburgh, PA 15213, USA.
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21
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22
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Leeson VC, Robbins TW, Matheson E, Hutton SB, Ron MA, Barnes TR, Joyce EM. Discrimination learning, reversal, and set-shifting in first-episode schizophrenia: stability over six years and specific associations with medication type and disorganization syndrome. Biol Psychiatry 2009; 66:586-93. [PMID: 19576575 PMCID: PMC2734076 DOI: 10.1016/j.biopsych.2009.05.016] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 04/21/2009] [Accepted: 05/05/2009] [Indexed: 11/13/2022]
Abstract
BACKGROUND The intradimensional/extradimensional (IDED) task assesses different forms of learning from feedback. Limited evidence suggests that attentional set-shifting deteriorates over time in schizophrenia. We tested this hypothesis and examined the specificity of learning impairments identified by this task. METHOD Two hundred sixty-two first-episode patients and 76 healthy control subjects, matched for age and premorbid IQ, were tested; 104 patients and 25 control subjects were reassessed 1 and 3 years later, and 31 patients were reassessed additionally 6 years later. RESULTS Patients showed impaired set-shifting that correlated with current IQ and working memory, but there were no impairments when subgroups were matched on current IQ. In contrast, patients showed marked impairments in rule reversal learning that survived correction for IQ, were present in the context of intact rule abstraction, and correlated with disorganization symptoms. Patients prescribed second-generation antipsychotics were worse on set-shifting compared with first-generation, a finding not explained by demographic data, illness characteristics, or IQ. Patients and control subjects showed stable IDED performance over the first 6 years of illness, although set-shifting was inconsistent over the first year. Those with residual negative symptoms were more likely to fail the set-shifting stage at follow-up. CONCLUSIONS First-episode schizophrenia patients can learn and generalize rules but are inflexible when rules change, reflecting reduced responsiveness to negative feedback and difficulty in switching attention. Rule-reversal is a promising target for translational studies, because it is specific, clinically relevant, and might reflect orbitofrontal dysfunction. Set-shifting is related to poor function more generally but might be sensitive to medication effects and valuable for clinical trials.
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Affiliation(s)
- Verity C. Leeson
- UCL Institute of Neurology, London, United Kingdom,Imperial College Faculty of Medicine, London, United Kingdom,Address correspondence to Verity C. Leeson, Ph.D., UCL Institute of Neurology, Room, 807 Queen Square House, Queen Square, London WC1N 3BG
| | - Trevor W. Robbins
- Department of Experimental Psychology, University of Cambridge, Cambridge, United Kingdom
| | | | | | - María A. Ron
- UCL Institute of Neurology, London, United Kingdom
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23
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Graham S, Jiang J, Manning V, Nejad AB, Zhisheng K, Salleh SR, Golay X, Berne YI, McKenna PJ. IQ-related fMRI differences during cognitive set shifting. Cereb Cortex 2009; 20:641-9. [PMID: 19571268 PMCID: PMC2820702 DOI: 10.1093/cercor/bhp130] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This event-related functional magnetic resonance imaging study compared neural correlates of executive function (cognitive set-shifting) in 28 healthy participants with either high (HIQ) or average (AIQ) intelligence. Despite comparable behavioral performance (except for slower reactions), the AIQ participants showed greater (especially prefrontal) activation during response selection; the HIQ participants showed greater activation (especially parietal) during feedback evaluation. HIQ participants appeared to engage cognitive resources to support more efficient strategies (planning during feedback in preparation for the upcoming response) which resulted in faster responses and less need for response inhibition and conflict resolution. Whether greater intelligence is associated with more or less brain activity (the “neural efficiency” debate) depends therefore on the specific component of the task being examined as well as the brain region recruited. One implication is that caution must be exercised when drawing conclusions from differences in activation between groups of individuals in whom IQ may differ (e.g., psychiatric vs. control samples).
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Affiliation(s)
- Steven Graham
- Functional Brain Imaging Lab, Department of Psychology, National University of Singapore, Singapore 117570.
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24
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Jahan A, Javan GK. Nonword repetition in schizophrenia: semantic long-term memory supports phonological loop. Psychiatry Clin Neurosci 2009; 63:426. [PMID: 19566777 DOI: 10.1111/j.1440-1819.2009.01957.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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25
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Huddy VC, Aron AR, Harrison M, Barnes TRE, Robbins TW, Joyce EM. Impaired conscious and preserved unconscious inhibitory processing in recent onset schizophrenia. Psychol Med 2009; 39:907-916. [PMID: 18796175 PMCID: PMC2682611 DOI: 10.1017/s0033291708004340] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 07/23/2008] [Accepted: 07/29/2008] [Indexed: 11/07/2022]
Abstract
BACKGROUND Impairments in inhibitory function have been found in studies of cognition in schizophrenia. These have been linked to a failure to adequately maintain the task demands in working memory. As response inhibition is known to occur in both voluntary and involuntary processes, an important question is whether both aspects of response inhibition are specifically impaired in people with schizophrenia. METHOD The subjects were 33 patients presenting with a first episode of psychosis (27 with schizophrenia and six with schizo-affective disorder) and 24 healthy controls. We administered two motor response tasks: voluntary response inhibition was indexed by the stop-signal task and involuntary response inhibition by the masked priming task. We also administered neuropsychological measures of IQ and executive function to explore their associations with response inhibition. RESULTS Patients with schizophrenia compared to healthy controls showed significantly increased duration of the voluntary response inhibition process, as indexed by the stop-signal reaction time (SSRT). By contrast, there were no group differences on the pattern of priming on the masked priming task, indicative of intact involuntary response inhibition. Neuropsychological measures revealed that voluntary response inhibition is not necessarily dependent on working memory. CONCLUSIONS These data provide evidence for a specific impairment of voluntary response inhibition in schizophrenia.
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Affiliation(s)
- V. C. Huddy
- Division of Neuroscience and Mental Health, Imperial
College London, UK
| | - A. R. Aron
- Department of Psychology, University of California San
Diego, USA
| | - M. Harrison
- Division of Neuroscience and Mental Health, Imperial
College London, UK
| | - T. R. E. Barnes
- Division of Neuroscience and Mental Health, Imperial
College London, UK
| | - T. W. Robbins
- Department of Experimental Psychology, University of
Cambridge, UK
| | - E. M. Joyce
- Institute of Neurology, University College London, UK
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26
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Raffard S, Bayard S, Gely-Nargeot MC, Capdevielle D, Maggi M, Barbotte E, Morris D, Boulenger JP. Insight and executive functioning in schizophrenia: a multidimensional approach. Psychiatry Res 2009; 167:239-50. [PMID: 19395049 DOI: 10.1016/j.psychres.2008.04.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2007] [Revised: 04/05/2008] [Accepted: 04/19/2008] [Indexed: 11/17/2022]
Abstract
Past research suggests that unawareness of illness in schizophrenia is associated with deficits in executive functions; however, the relationships between executive processes and the various dimensions of insight are still unclear. Recent models of executive functioning have proposed that four executive processes - inhibition, updating, shifting and dual task coordination - are moderately related yet separable. In this study, we proposed to investigate and clarify the relationships between insight dimensions and the aforementioned four executive components. A total of 60 patients were administered the Test for Attentional Performance and the Scale to Assess Unawareness of Mental Disorder. The effect of potential confounding variables such as medication, symptomatology, demography, psycho-affective state, and general processing speed were also examined in a preliminary statistical analysis. We found that both awareness of disorder and awareness of response to medication were significantly related to Updating. Awareness of the social consequences of the disease was significantly related to Updating, Divided Attention and Inhibition Processes. The analysis indicates that poor insight in schizophrenia may be partially related to executive dysfunction. Finally, our study emphasizes the possible role of neuropsychological intervention in improving patients' insight into illness.
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Affiliation(s)
- Stéphane Raffard
- University Department of Adult Psychiatry, CHU, Université Montpellier 1, France.
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27
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Lewis DA, Sweet RA. Schizophrenia from a neural circuitry perspective: advancing toward rational pharmacological therapies. J Clin Invest 2009; 119:706-16. [PMID: 19339762 DOI: 10.1172/jci37335] [Citation(s) in RCA: 174] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Schizophrenia is a severe disorder that disrupts the function of multiple brain systems, resulting in impaired social and occupational functioning. The etiology and pathogenesis of schizophrenia appear to involve the interplay of a potentially large number of genetic liabilities and adverse environmental events that disrupt brain developmental pathways. In this Review, we discuss a strategy for determining how particular common and core clinical features of the illness are associated with pathophysiology in certain circuits of the cerebral cortex. The identification of molecular alterations in these circuits is providing critical insights for the rational development of new therapeutic interventions.
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Affiliation(s)
- David A Lewis
- University of Pittsburgh,Department of Psychiatry, W1651 Biomedical Science Tower, 3811 O'Hara Street, Pittsburgh, Pennsylvania 15213, USA.
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28
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Cell and receptor type-specific alterations in markers of GABA neurotransmission in the prefrontal cortex of subjects with schizophrenia. Neurotox Res 2009; 14:237-48. [PMID: 19073429 DOI: 10.1007/bf03033813] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Impairments in cognitive control, such as those involved in working memory, are associated with dysfunction of the dorsolateral prefrontal cortex (DLPFC) in individuals with schizophrenia. This dysfunction appears to result, at least in part, from abnormalities in GABA-mediated neurotransmission. In this paper, we review recent findings indicating that the altered DLPFC circuitry in subjects with schizophrenia reflects changes in the expression of genes that encode selective presynaptic and postsynaptic components of GABA neurotransmission. Specifically, using a combination of methods, we found that subjects with schizophrenia exhibited expression deficits in GABA-related transcripts encoding presynaptic regulators of GABA neurotransmission, neuropeptide markers of specific subpopulations of GABA neurons, and certain subunits of the GABA(A) receptor. In particular, alterations in the expression of the neuropeptide somatostatin suggested that GABA neurotransmission is impaired in the Martinotti subset of GABA neurons that target the dendrites of pyramidal cells. In contrast, none of the GABA-related transcripts assessed to date were altered in the DLPFC of monkeys chronically exposed to antipsychotic medications, suggesting that the effects observed in the human studies reflect the disease process and not its treatment. In concert with previous findings, these data suggest that working memory dysfunction in schizophrenia may be attributable to altered GABA neurotransmission in specific DLPFC microcircuits.
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29
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Morrow SA, Kaushik T, Zarevics P, Erlanger D, Bear MF, Munschauer FE, Benedict RHB. The effects of L-amphetamine sulfate on cognition in MS patients: results of a randomized controlled trial. J Neurol 2009; 256:1095-102. [PMID: 19263186 DOI: 10.1007/s00415-009-5074-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 02/06/2009] [Accepted: 02/12/2009] [Indexed: 11/30/2022]
Abstract
Defects in processing speed and memory are common in multiple sclerosis (MS) patients. In other populations, amphetamines have been shown to enhance cognition, but their use is limited by adverse behavioral effects. The L-isomer may have equivalent cognition enhancement with less adverse effects due to decreased potency in subcortical areas. The aim of this study was to assess the safety and efficacy of L-amphetamine sulfate in the treatment of cognitive dysfunction in MS. This was a 2:1 randomized, placebo-controlled, double-blind trial, involving 33 MS clinics across the USA. One hundred and fifty-one clinically definite MS patients with documented cognitive dysfunction who were relapse free for >or=90 days, with an Expanded Disability Status Scale (EDSS) <or=6.5, and with no other medical/psychiatric condition that may cause psychological dysfunction were randomized to 30 mg of oral L-amphetamine sulfate or placebo for 29 days, including a dose escalation period. A history of cardiac disease, uncontrolled hypertension or electrocardiograph abnormalities resulted in exclusion. The primary outcomes were the Subject Global Assessment of Change and Symbol Digit Modalities Test (SDMT). Secondary outcomes were the results from the California Verbal Learning Test, second edition (CVLT2), Brief Visual Memory Test-Revised (BVMTR), and Paced Auditory Serial Addition Test (PASAT). One hundred and thirty-six subjects completed the study. No differences were found at baseline in demographics or in the results of the neuropsychological tests. After treatment, the active group performed significantly better for total learning (P = 0.041) and delayed recall (P < 0.01) on the BVMTR, and for delayed recall (P = 0.012) on the CVLT2. Five patients (four from the treatment group, one placebo) withdrew due to intolerable adverse events. L-amphetamine sulfate was associated with improved learning and memory and was well tolerated in this study. However, because the positive findings were observed on secondary outcome measures, the study requires replication before L: -amphetamine sulfate can be recommended for the treatment of cognitive impairment in MS.
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Affiliation(s)
- Sarah A Morrow
- Jacobs Neurological Institute, State University of New York at Buffalo, 100 High Street, Buffalo, NY 14215, USA
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Driesen N, Leung HC, Calhoun V, Constable R, Gueorguieva R, Hoffman R, Skudlarski P, Goldman-Rakic P, Krystal J. Impairment of working memory maintenance and response in schizophrenia: functional magnetic resonance imaging evidence. Biol Psychiatry 2008; 64:1026-34. [PMID: 18823880 PMCID: PMC2650279 DOI: 10.1016/j.biopsych.2008.07.029] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 06/15/2008] [Accepted: 07/25/2008] [Indexed: 11/26/2022]
Abstract
BACKGROUND Comparing prefrontal cortical activity during particular phases of working memory in healthy subjects and individuals diagnosed with schizophrenia might help to define the phase-specific deficits in cortical function that contribute to cognitive impairments associated with schizophrenia. This study featured a spatial working memory task, similar to that used in nonhuman primates, that was designed to facilitate separating brain activation into encoding, maintenance, and response phases. METHODS Fourteen patients with schizophrenia (4 medication-free) and 12 healthy comparison participants completed functional magnetic resonance imaging while performing a spatial working memory task with two levels of memory load. RESULTS Task accuracy was similar in patients and healthy participants. However, patients showed reductions in brain activation during maintenance and response phases but not during the encoding phase. The reduced prefrontal activity during the maintenance phase of working memory was attributed to a greater rate of decay of prefrontal activity over time in patients. Cortical deficits in patients did not appear to be related to antipsychotic treatment. In patients and in healthy subjects, the time-dependent reduction in prefrontal activity during working memory maintenance correlated with poorer performance on the memory task. CONCLUSIONS Overall, these data highlight that basic research insights into the distinct neurobiologies of the maintenance and response phases of working memory are of potential importance for understanding the neurobiology of cognitive impairment in schizophrenia and advancing its treatment.
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Affiliation(s)
- N.R. Driesen
- Department of Psychiatry, Yale University School of Medicine (YSM), New Haven, CT, Department of Neurology, YSM, New Haven, CT, VA Schizophrenia Biological Research Center (116-A), VA Connecticut Healthcare System, 950 Campbell Ave., West Haven, CT,Correspondence should be addressed to: Naomi Driesen, Ph.D., Dept. of Psychiatry, YSM, Ribicoff Research Facilities, CMHC, 34 Park Street, New Haven, CT 06519, (203)974-7259,
| | - H-C. Leung
- Department of Psychology, State University of New York at Stony Brook, Stony Brook, NY
| | - V.D. Calhoun
- Department of Psychiatry, Yale University School of Medicine (YSM), New Haven, CT, Department of Computer and Electrical Engineering, University of New Mexico, Albuquerque, New Mexico, Mind Institute, University of New Mexico, Albuquerque, New Mexico
| | | | - R. Gueorguieva
- , Department of Epidemiology and Public Health, YSM, New Haven, CT
| | - R. Hoffman
- Department of Psychiatry, Yale University School of Medicine (YSM), New Haven, CT
| | | | | | - J.H. Krystal
- Department of Psychiatry, Yale University School of Medicine (YSM), New Haven, CT, VA Schizophrenia Biological Research Center (116-A), VA Connecticut Healthcare System, 950 Campbell Ave., West Haven, CT
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Distinct conflict resolution deficits related to different facets of Schizophrenia. PSYCHOLOGICAL RESEARCH 2008; 73:786-93. [PMID: 19034500 DOI: 10.1007/s00426-008-0195-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Accepted: 10/01/2008] [Indexed: 10/21/2022]
Abstract
An important issue in understanding the nature of conflict processing is whether it is a unitary or multidimensional construct. One way to examine this is to study whether people with impaired conflict processing exhibit a general pattern of deficits or whether they exhibit impairments in distinct aspects of conflict processing. One group who might exhibit conflict deficits are people with schizophrenia. Schizophrenia is a heterogeneous disorder, with one way to break down the heterogeneity of schizophrenia is to examine specific symptoms. Previous research has found that specific symptoms of schizophrenia are associated with specific deficits in conflict processing. In particular, disorganization is associated with increased response conflict, alogia is associated with increased retrieval conflict, and anhedonia is associated with increased emotional conflict. Moreover, there is evidence that different types of conflict processing are unassociated with each other. This evidence suggests that conflict processing is a multidimensional construct and that different aspects of schizophrenia are associated with impairments in processing different types of conflict.
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Imaging the brain: visualising “pathological entities”? Searching for reliable protocols within psychiatry and their impact on the understanding of psychiatric diseases. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s10202-008-0055-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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van Beveren NJM, de Haan L. A visual metaphor describing neural dynamics in schizophrenia. PLoS One 2008; 3:e2577. [PMID: 18648540 PMCID: PMC2481285 DOI: 10.1371/journal.pone.0002577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Accepted: 05/27/2008] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND In many scientific disciplines the use of a metaphor as an heuristic aid is not uncommon. A well known example in somatic medicine is the 'defense army metaphor' used to characterize the immune system. In fact, probably a large part of the everyday work of doctors consists of 'translating' scientific and clinical information (i.e. causes of disease, percentage of success versus risk of side-effects) into information tailored to the needs and capacities of the individual patient. The ability to do so in an effective way is at least partly what makes a clinician a good communicator. Schizophrenia is a severe psychiatric disorder which affects approximately 1% of the population. Over the last two decades a large amount of molecular-biological, imaging and genetic data have been accumulated regarding the biological underpinnings of schizophrenia. However, it remains difficult to understand how the characteristic symptoms of schizophrenia such as hallucinations and delusions are related to disturbances on the molecular-biological level. In general, psychiatry seems to lack a conceptual framework with sufficient explanatory power to link the mental- and molecular-biological domains. METHODOLOGY/PRINCIPAL FINDINGS Here, we present an essay-like study in which we propose to use visualized concepts stemming from the theory on dynamical complex systems as a 'visual metaphor' to bridge the mental- and molecular-biological domains in schizophrenia. We first describe a computer model of neural information processing; we show how the information processing in this model can be visualized, using concepts from the theory on complex systems. We then describe two computer models which have been used to investigate the primary theory on schizophrenia, the neurodevelopmental model, and show how disturbed information processing in these two computer models can be presented in terms of the visual metaphor previously described. Finally, we describe the effects of dopamine neuromodulation, of which disturbances have been frequently described in schizophrenia, in terms of the same visualized metaphor. CONCLUSIONS/SIGNIFICANCE The conceptual framework and metaphor described offers a heuristic tool to understand the relationship between the mental- and molecular-biological domains in an intuitive way. The concepts we present may serve to facilitate communication between researchers, clinicians and patients.
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Affiliation(s)
| | - Lieuwe de Haan
- Department of Psychiatry, Academic Medical Center/de Meren, Amsterdam, The Netherlands
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Rüsch N, Tebartz van Elst L, Valerius G, Büchert M, Thiel T, Ebert D, Hennig J, Olbrich HM. Neurochemical and structural correlates of executive dysfunction in schizophrenia. Schizophr Res 2008; 99:155-63. [PMID: 17616347 DOI: 10.1016/j.schres.2007.05.024] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Revised: 04/27/2007] [Accepted: 05/15/2007] [Indexed: 11/30/2022]
Abstract
BACKGROUND Executive dysfunction is a core feature of schizophrenia. The neurochemical and structural changes associated with this deficit are, however, largely unclear. This study tested the hypothesis that changes in glutamate, glutamine and N-acetyl-aspartate (NAA) in hippocampal and dorsolateral prefrontal (DLPFC) regions as well as hippocampal, amygdalar and DLPFC volume reductions are associated with executive dysfunction. METHODS Twenty-nine subjects with schizophrenia and 31 healthy controls were examined by short-echo single voxel magnetic resonance spectroscopy of the left anterior hippocampus and the left DLPFC. Volumes of the hippocampi, amygdalae and DLPFC were measured bilaterally using manual volumetry. Executive functioning was assessed by the Wisconsin Card Sorting Test (WCST). RESULTS Poor WCST performance was associated with increased hippocampal glutamate concentrations among subjects with schizophrenia, not among healthy controls. Glutamate in the DLPFC as well as NAA or glutamine in the hippocampus or the DLPFC were not related to executive functioning in schizophrenia or healthy controls. Reduced amygdalar volume was associated with impaired executive functioning in subjects with schizophrenia (p=.06) and healthy controls (p=.04). CONCLUSIONS Altered hippocampal glutamatergic neurotransmission and amygdalar volume loss may be associated with executive dysfunction in schizophrenia.
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Affiliation(s)
- Nicolas Rüsch
- Department of Psychiatry and Psychotherapy, University of Freiburg, Germany
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Sacchetti E, Galluzzo A, Panariello A, Parrinello G, Cappa SF. Self-ordered pointing and visual conditional associative learning tasks in drug-free schizophrenia spectrum disorder patients. BMC Psychiatry 2008; 8:6. [PMID: 18215296 PMCID: PMC2245938 DOI: 10.1186/1471-244x-8-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Accepted: 01/23/2008] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND There is evidence of a link between schizophrenia and a deficit of working memory, but this has been derived from tasks not specifically developed to probe working memory per se. Our aim was to investigate whether working memory deficits may be detected across different paradigms using the self-ordered pointing task (SOPT) and the visual conditional associative learning task (VCALT) in patients with schizophrenia spectrum disorders and healthy controls. The current literature suggests deficits in schizophrenia spectrum disorder patients versus healthy controls but these studies frequently involved small samples, broad diagnostic criteria, inclusion of patients on antipsychotic medications, and were not controlled for symptom domains, severity of the disorder, etc. To overcome some of these limitations, we investigated the self-monitoring and conditional associative learning abilities of a numerically representative sample of healthy controls and a group of non-deteriorated, drug-free patients hospitalized for a schizophrenia spectrum disorder with florid, mainly positive psychotic symptoms. METHODS Eighty-five patients with a schizophrenia spectrum disorder (DSM-IV-TR diagnosis of schizophrenia (n = 71) or schizophreniform disorder (n = 14)) and 80 healthy controls entered the study. The clinical picture was dominated by positive symptoms. The healthy control group had a negative personal and family history of schizophrenia or mood disorder and satisfied all the inclusion and exclusion criteria other than variables related to schizophrenia spectrum disorders. RESULTS Compared to controls, patients had worse performances on SOPT, VCALT and higher SOPT/VCALT ratios, not affected by demographic or clinical variables. ROC curves showed that SOPT, VCALT, and SOPT/VCALT ratio had good accuracy in discriminating patients from controls. The SOPT and VCALT scores were inter-correlated in controls but not in patients. CONCLUSION The selection of a clinically homogeneous group of patients, controlled for a number of potential confounding factors, and the high level of significance found in the different analyses confirm the presence of SOPT and VCALT abnormalities in a large preponderance of patients with schizophrenia spectrum disorder with positive symptoms. SOPT, VCALT, and SOPT/VCALT ratio showed good accuracy in discriminating patients from healthy controls. These conclusions cannot be extended to schizophrenia spectrum disorder patients with a different clinical profile from our patient population.
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Affiliation(s)
- Emilio Sacchetti
- Department of Psychiatry, Brescia University School of Medicine, Brescia, Italy.
| | - Alessandro Galluzzo
- University Psychiatric Unit, Brescia University School of Medicine and Brescia Spedali Civili, Brescia, Italy,Department of Mental Health, Brescia Spedali Civili, Brescia, Italy
| | - Adelaide Panariello
- University Psychiatric Unit, Brescia University School of Medicine and Brescia Spedali Civili, Brescia, Italy,Department of Mental Health, Brescia Spedali Civili, Brescia, Italy
| | - Giovanni Parrinello
- Department of Biomedical Sciences and Biotechnologies Section of Medical Statistics and Biometry, Brescia University School of Medicine, Brescia, Italy
| | - Stefano Francesco Cappa
- Departments of Psychology and Neuroscience, Vita e Salute San Raffaele University, Milan, Italy
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Abstract
The core features of schizophrenia include deficits in cognitive processes mediated by the circuitry of the dorsolateral prefrontal cortex (DLPFC). These deficits are associated with a range of molecular and morphological alterations in the DLPFC, each of which could be a cause, consequence, or compensation in relation to other changes, and thus reflect the neuroplasticity of the brain in response to the underlying disease process. In this review, we consider disturbances in excitatory, inhibitory, and modulatory connections of DLPFC circuitry from the perspective of disease- and development-related neuroplasticity and discuss their implications for the identification of novel therapeutic targets.
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Affiliation(s)
- David A Lewis
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Barrantes-Vidal N, Aguilera M, Campanera S, Fatjó-Vilas M, Guitart M, Miret S, Valero S, Fañanás L. Working memory in siblings of schizophrenia patients. Schizophr Res 2007; 95:70-5. [PMID: 17628433 DOI: 10.1016/j.schres.2007.06.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Revised: 06/19/2007] [Accepted: 06/25/2007] [Indexed: 11/21/2022]
Abstract
UNLABELLED Working memory (WM) has hardly been explored in non-psychotic relatives of schizophrenic patients despite its potential suitability as a neurocognitive endophenotype. Indeed, WM modalities, components and processes have rarely been compared in the same group of relatives. The present study examined neurocognitive performance in healthy siblings of schizophrenic patients, including both spatial and verbal WM modalities and tests tapping maintenance (Spatial Span Backwards and CPT-IP d') and manipulative (Letters and Numbers Sequencing) WM processes. METHODS 68 schizophrenia patients, 38 healthy siblings and 63 controls were assessed on IQ, attention, memory, WM, and executive functions. Cluster A symptoms were screened out in siblings and controls. RESULTS Siblings had an intermediate performance between that of schizophrenic patients and controls. They performed worse than controls on IQ, LNS, animal naming, backwards spatial span, phonemic fluency, numbers d', and forward spatial span. DISCUSSION Consistent with the WM literature in schizophrenia, both verbal and spatial WM differed significantly between siblings and controls, suggesting that WM deficits are modality independent. Our results failed to support the hypothesis that tests tapping WM manipulative processes heavily loading on DLFPC are quantitatively more impaired in relatives and, therefore, more sensitive to liability for schizophrenia. However, firm conclusions cannot be drawn until more studies assessing both maintenance and manipulative WM processes in relatives are available.
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Affiliation(s)
- Neus Barrantes-Vidal
- Departament de Biologia Animal, Unitat d'Antropologia, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal, 645, 08028-Barcelona, Spain.
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Rüsch N, Spoletini I, Wilke M, Bria P, Di Paola M, Di Iulio F, Martinotti G, Caltagirone C, Spalletta G. Prefrontal-thalamic-cerebellar gray matter networks and executive functioning in schizophrenia. Schizophr Res 2007; 93:79-89. [PMID: 17383859 DOI: 10.1016/j.schres.2007.01.029] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 01/31/2007] [Accepted: 01/31/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Poor executive functioning is a core deficit in schizophrenia and has been linked to frontal lobe alterations. We aimed to identify (1) prefrontal cerebral areas in which decreased volume is linked to executive dysfunction in schizophrenia; and (2) areas throughout the brain that are volumetrically related to the prefrontal area identified in the first analysis, thus detecting more extended volumetric networks associated with executive functioning. METHOD Fifty-three outpatients with schizophrenia and 62 healthy controls, matched for age, gender and handedness, were recruited. High-resolution images were acquired on a 1.5 tesla scanner and regional gray and white matter volumes were analyzed by voxel-based morphometry within SPM5 (statistical parametric mapping, University College London, UK). Executive functioning was assessed using the Wisconsin Card Sorting Test (WCST). RESULTS Twenty-one patients with poor executive functioning showed reduced dorsolateral prefrontal and anterior cingulate gray matter volume as compared to 30 patients with high WCST performance, with a maximum effect in the left dorsolateral prefrontal cortex. Left dorsolateral prefrontal gray matter volume predicted WCST performance after controlling for possible confounding effects of global cognitive functioning, verbal attention span, negative symptoms, illness duration and education. In this area, both patient groups had less gray matter than healthy controls. Left dorsolateral prefrontal gray matter volume was positively related to dorsal prefrontal, anterior cingulate and parietal gray matter volume; and negatively related to thalamic, cerebellar, pontine and right parahippocampal gray matter volume. CONCLUSIONS Volumetric alterations in prefrontal-thalamic-cerebellar gray matter networks may lead to executive dysfunction in schizophrenia.
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Bolton C, Gooding P, Kapur N, Barrowclough C, Tarrier N. Developing psychological perspectives of suicidal behaviour and risk in people with a diagnosis of schizophrenia: We know they kill themselves but do we understand why? Clin Psychol Rev 2007; 27:511-36. [PMID: 17229508 DOI: 10.1016/j.cpr.2006.12.001] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
People with a diagnosis of schizophrenia are at increased risk of suicidal behaviour yet little is understood of the psychological underpinnings of this vulnerability. The biopsychosocial 'Cry of Pain' model [Williams, J.M.G. (1997). Cry of pain. Harmondsworth: Penguin.] provides a broad framework from which to understand suicidal behaviour. However, the utility of the model in relation to suicide in schizophrenia has not yet been explored. This was the primary goal of this paper. Six components of the 'Cry of Pain' model were identified and evaluated with respect to whether they contributed to i. common transdiagnostic factors underlying suicide, ii. factors relating to co-morbid depression which account for suicidal behaviour, or iii. factors which are specific to schizophrenia and underlie suicide risk. The potential for applying the model to clinical management of suicide in schizophrenia is illustrated.
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Schweitzer JB, Hanford RB, Medoff DR. Working memory deficits in adults with ADHD: is there evidence for subtype differences? Behav Brain Funct 2006; 2:43. [PMID: 17173676 PMCID: PMC1762010 DOI: 10.1186/1744-9081-2-43] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Accepted: 12/15/2006] [Indexed: 05/13/2023] Open
Abstract
BACKGROUND Working memory performance is important for maintaining functioning in cognitive, academic and social activities. Previous research suggests there are prevalent working memory deficits in children with attention deficit hyperactivity disorder (ADHD). There is now a growing body of literature characterizing working memory functioning according to ADHD subtypes in children. The expression of working memory deficits in adults with ADHD and how they vary according to subtype, however, remains to be more fully documented. METHODS This study assessed differences in working memory functioning between Normal Control (NC) adults (N = 18); patients with ADHD, Combined (ADHD-CT) Type ADHD (N = 17); and ADHD, Inattentive (ADHD-IA) Type (N = 16) using subtests from the Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-III and the Paced Auditory Serial Addition Task (PASAT). RESULTS The ADHD groups displayed significant weaknesses in contrast to the NC group on working memory tests requiring rapid processing and active stimulus manipulation. This included the Letter-Number-Sequencing test of the Wechsler scales, PASAT omission errors and the longest sequence of consecutive correct answers on the PASAT. No overall ADHD group subtype differences emerged; however differences between the ADHD groups and the NC group varied depending on the measure and the gender of the participants. Gender differences in performance were evident on some measures of working memory, regardless of group, with males performing better than females. CONCLUSION In general, the data support a dimensional interpretation of working memory deficits experienced by the ADHD-CT and ADHD-IA subtypes, rather than an absolute difference between subtypes. Future studies should test the effects of processing speed and load on subtype performance and how those variables interact with gender in adults with ADHD.
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Affiliation(s)
- Julie B Schweitzer
- Division of Child Psychiatry, Department of Psychiatry, 737 W. Lombard St., Suite 442, University of Maryland School of Medicine, Baltimore, Maryland, 21201, USA
| | - Russell B Hanford
- Department of Psychology, 532 Kilgo Circle, Emory University, Atlanta, Georgia, 30322, USA
| | - Deborah R Medoff
- Division of Services Research, Department of Psychiatry, 737 W. Lombard St., University of Maryland School of Medicine, Baltimore, Maryland, 21201, USA
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Lewis DA, Gonzalez-Burgos G. Pathophysiologically based treatment interventions in schizophrenia. Nat Med 2006; 12:1016-22. [PMID: 16960576 DOI: 10.1038/nm1478] [Citation(s) in RCA: 268] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Identifying the molecular alterations that underlie the pathophysiology of critical clinical features of schizophrenia is an essential step in the rational development of new therapeutic interventions for this devastating illness. Cognitive deficits, such as the impairments in working memory that arise from dysfunction of the dorsolateral prefrontal cortex, are a major determinant of functional outcome in schizophrenia. Here we consider the contributions of disturbances in glutamate, dopamine and GABA neurotransmission to the pathophysiology of working memory impairments in schizophrenia, suggest a cascade of molecular events that might link these disturbances, and argue that the molecular alterations most proximal to the pathophysiology of prefrontal dysfunction offer the most promise as targets for new drug development.
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Affiliation(s)
- David A Lewis
- Department of Psychiatry, University of Pittsburgh, 3811 O'Hara Street, Pittsburgh, Pennsylvania 15213, USA.
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Repovs G, Baddeley A. The multi-component model of working memory: Explorations in experimental cognitive psychology. Neuroscience 2006; 139:5-21. [PMID: 16517088 DOI: 10.1016/j.neuroscience.2005.12.061] [Citation(s) in RCA: 325] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 11/28/2005] [Accepted: 12/04/2005] [Indexed: 10/24/2022]
Abstract
There are a number of ways one can hope to describe and explain cognitive abilities, each of them contributing a unique and valuable perspective. Cognitive psychology tries to develop and test functional accounts of cognitive systems that explain the capacities and properties of cognitive abilities as revealed by empirical data gathered by a range of behavioral experimental paradigms. Much of the research in the cognitive psychology of working memory has been strongly influenced by the multi-component model of working memory [Baddeley AD, Hitch GJ (1974) Working memory. In: Recent advances in learning and motivation, Vol. 8 (Bower GA, ed), pp 47-90. New York: Academic Press; Baddeley AD (1986) Working memory. Oxford, UK: Clarendon Press; Baddeley A. Working memory: Thought and action. Oxford: Oxford University Press, in press]. By expanding the notion of a passive short-term memory to an active system that provides the basis for complex cognitive abilities, the model has opened up numerous questions and new lines of research. In this paper we present the current revision of the multi-component model that encompasses a central executive, two unimodal storage systems: a phonological loop and a visuospatial sketchpad, and a further component, a multimodal store capable of integrating information into unitary episodic representations, termed episodic buffer. We review recent empirical data within experimental cognitive psychology that has shaped the development of the multicomponent model and the understanding of the capacities and properties of working memory. Research based largely on dual-task experimental designs and on neuropsychological evidence has yielded valuable information about the fractionation of working memory into independent stores and processes, the nature of representations in individual stores, the mechanisms of their maintenance and manipulation, the way the components of working memory relate to each other, and the role they play in other cognitive abilities. With many questions still open and new issues emerging, we believe that the multicomponent model will continue to stimulate research while providing a comprehensive functional description of working memory.
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Affiliation(s)
- G Repovs
- Department of Psychology, Washington University, Campus Box 1125, One Brookings Drive, St. Louis, MO 63130, USA.
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