1
|
Byrne A, Martin D, Jones C, Galbraith N, Mercer T. Conspiracy theory beliefs in the adolescent population: A systematic review. J Adolesc 2024. [PMID: 38477391 DOI: 10.1002/jad.12316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024]
Abstract
INTRODUCTION While the study of conspiracy theory beliefs is a relatively new research area, there has been a rise in academic interest in recent years. The literature provides evidence of relationships between conspiracy theory beliefs and a range of factors, but the vast majority of studies are limited to adult samples, and it is unclear how such beliefs present in adolescence. METHODS The systematic review was conducted according to the PRISMA-S format. Relevant databases were searched up to February 23, 2023, for quantitative studies related to adolescent conspiracy theory beliefs. RESULTS The six included articles show that conspiracy theory beliefs are present from the start of adolescence, and stable from age 14 upwards, with correlations reported for mistrust and paranoid thinking. Negative relationships were reported for cognitive factors such as ontological confusion, cognitive ability, and actively open-minded thinking. Health-related beliefs correlated with adverse childhood experiences, peer problems, conduct, and sociodemographic factors. Right-wing authoritarianism and anxiety positively correlated with intergroup conspiracy theory beliefs. CONCLUSION While some factors from adult studies are replicated in the review, there are differences between age groups. The age at which conspiracy theory beliefs begin to form indicate developmental aspects of adolescence, and possibly childhood, that require further examination. Cognitive factors show promise for interventions and should be explored further. However, the lack of studies using adolescent populations is an issue that must be resolved for a greater understanding of conspiracy theory beliefs and a move toward effective interventions.
Collapse
Affiliation(s)
- Anthony Byrne
- School of Psychology, Faculty of Education, Health, and Wellbeing, University of Wolverhampton, Wolverhampton, UK
| | - David Martin
- School of Psychology, Faculty of Education, Health, and Wellbeing, University of Wolverhampton, Wolverhampton, UK
| | - Claire Jones
- School of Psychology, Faculty of Education, Health, and Wellbeing, University of Wolverhampton, Wolverhampton, UK
| | - Niall Galbraith
- School of Psychology, Faculty of Education, Health, and Wellbeing, University of Wolverhampton, Wolverhampton, UK
| | - Tom Mercer
- School of Psychology, Faculty of Education, Health, and Wellbeing, University of Wolverhampton, Wolverhampton, UK
| |
Collapse
|
2
|
Karamaouna P, Zouraraki C, Economou E, Kafetsios K, Bitsios P, Giakoumaki SG. Cold executive function processes and their hot analogs in schizotypy. J Int Neuropsychol Soc 2024; 30:285-294. [PMID: 37750805 DOI: 10.1017/s1355617723000590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
OBJECTIVE To examine cold (based on logical reasoning) versus hot (having emotional components) executive function processes in groups with high individual schizotypal traits. METHOD Two-hundred and forty-seven participants were administered the Schizotypal Personality Questionnaire and were allocated into schizotypal (cognitive-perceptual, paranoid, negative, disorganized) or control groups according to pre-specified criteria. Participants were also administered a battery of tasks examining working memory, complex selective attention, response inhibition, decision-making and fluid intelligence and their affective counterparts. The outcome measures of each task were reduced to one composite variable thus formulating five cold and five hot cognitive domains. Between-group differences in the cognitive domains were examined with repeated measures analyses of covariance. RESULTS For working memory, the control and the cognitive-perceptual groups outperformed negative schizotypes, while for affective working memory controls outperformed the disorganized group. Controls also scored higher compared with the disorganized group in complex selective attention, while both the control and the cognitive-perceptual groups outperformed negative schizotypes in complex affective selective attention. Negative schizotypes also had striking difficulties in response inhibition, as they scored lower compared with all other groups. Despite the lack of differences in fluid intelligence, controls scored higher compared with all schizotypal groups (except from cognitive-perceptual schizotypes) in emotional intelligence; the latter group reported higher emotional intelligence compared with negative schizotypes. CONCLUSION Results indicate that there is no categorical association between the different schizotypal dimensions with solely cold or hot executive function processes and support impoverished emotional intelligence as a core feature of schizotypy.
Collapse
Affiliation(s)
- Penny Karamaouna
- Laboratory of Neuropsychology, Department of Psychology, School of Social Sciences, University of Crete, Rethymno, Crete, Greece
- University of Crete Research Center for the Humanities, the Social and Education Sciences (UCRC), University of Crete, Rethymno, Crete, Greece
| | - Chrysoula Zouraraki
- Laboratory of Neuropsychology, Department of Psychology, School of Social Sciences, University of Crete, Rethymno, Crete, Greece
- University of Crete Research Center for the Humanities, the Social and Education Sciences (UCRC), University of Crete, Rethymno, Crete, Greece
| | - Elias Economou
- Laboratory of Experimental Psychology, Department of Psychology, School of Social Sciences, University of Crete, Rethymno, Crete, Greece
| | | | - Panos Bitsios
- Department of Psychiatry and Behavioural Sciences, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Stella G Giakoumaki
- Laboratory of Neuropsychology, Department of Psychology, School of Social Sciences, University of Crete, Rethymno, Crete, Greece
- University of Crete Research Center for the Humanities, the Social and Education Sciences (UCRC), University of Crete, Rethymno, Crete, Greece
| |
Collapse
|
3
|
Diao M, Demchenko I, Asare G, Chen Y, Debruille JB. Quantifying the effects of practicing a semantic task according to subclinical schizotypy. Sci Rep 2024; 14:2900. [PMID: 38316943 PMCID: PMC10844607 DOI: 10.1038/s41598-024-53468-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 01/31/2024] [Indexed: 02/07/2024] Open
Abstract
The learning ability of individuals within the schizophrenia spectrum is crucial for their psychosocial rehabilitation. When selecting a treatment, it is thus essential to consider the impact of medications on practice effects, an important type of learning ability. To achieve this end goal, a pre-treatment test has to be developed and tested in healthy participants first. This is the aim of the current work, which takes advantage of the schizotypal traits present in these participants to preliminary assess the test's validity for use among patients. In this study, 47 healthy participants completed the Schizotypal Personality Questionnaire (SPQ) and performed a semantic categorization task twice, with a 1.5-hour gap between sessions. Practice was found to reduce reaction times (RTs) in both low- and high-SPQ scorers. Additionally, practice decreased the amplitudes of the N400 event-related brain potentials elicited by semantically matching words in low SPQ scorers only, which shows the sensitivity of the task to schizotypy. Across the two sessions, both RTs and N400 amplitudes had good test-retest reliability. This task could thus be a valuable tool. Ongoing studies are currently evaluating the impact of fully deceptive placebos and of real antipsychotic medications on these practice effects. This round of research should subsequently assist psychiatrists in making informed decisions about selecting the most suitable medication for the psychosocial rehabilitation of a patient.
Collapse
Affiliation(s)
- Mingyi Diao
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Neurosciences, McGill University, Montreal, QC, Canada
| | - Ilya Demchenko
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Neurosciences, McGill University, Montreal, QC, Canada
| | - Gifty Asare
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Yelin Chen
- Douglas Mental Health University Institute, Montreal, QC, Canada
- Department of Psychology, McGill University, Montreal, QC, Canada
| | - J Bruno Debruille
- Douglas Mental Health University Institute, Montreal, QC, Canada.
- Department of Neurosciences, McGill University, Montreal, QC, Canada.
- Department of Psychiatry, McGill University, Montreal, QC, Canada.
- Department of Psychology, McGill University, Montreal, QC, Canada.
| |
Collapse
|
4
|
Kassim FM, Lim JHM, Slawik SV, Gaus K, Peters B, Lee JWY, Hepple EK, Rodger J, Albrecht MA, Martin-Iverson MT. The effects of caffeine and d-amphetamine on spatial span task in healthy participants. PLoS One 2023; 18:e0287538. [PMID: 37440493 PMCID: PMC10343048 DOI: 10.1371/journal.pone.0287538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 06/06/2023] [Indexed: 07/15/2023] Open
Abstract
Studies that examined the effect of amphetamine or caffeine on spatial working memory (SWM) and verbal working memory (VWM) have used various tasks. However, there are no studies that have used spatial span tasks (SSTs) to assess the SWM effect of amphetamine and caffeine, although some studies have used digit span tasks (DST) to assess VWM. Previous reports also showed that increasing dopamine increases psychosis-like experiences (PLE, or schizotypy) scores which are in turn negatively associated with WM performance in people with high schizotypy and people with schizophrenia. Therefore, the present study aimed to examine the influence of d-amphetamine (0.45 mg/kg, PO), a dopamine releasing stimulant, on SST, DST, and on PLE in healthy volunteers. In a separate study, we examined the effect of caffeine, a nonspecific adenosine receptor antagonist with stimulant properties, on similar tasks. METHODS Healthy participants (N = 40) took part in two randomized, double-blind, counter-balanced placebo-controlled cross-over pilot studies: The first group (N = 20) with d-amphetamine (0.45 mg/kg, PO) and the second group (N = 20) with caffeine (200 mg, PO). Spatial span and digit span were examined under four delay conditions (0, 2, 4, 8 s). PLE were assessed using several scales measuring various aspects of psychosis and schizotypy. RESULTS We failed to find an effect of d-amphetamine or caffeine on SWM or VWM, relative to placebo. However, d-amphetamine increased a composite score of psychosis-like experiences (p = 0.0005), specifically: Scores on Brief Psychiatric Rating Scale, Perceptual Aberrations Scale, and Magical Ideation Scale were increased following d-amphetamine. The degree of change in PLE following d-amphetamine negatively and significantly correlated with changes in SWM, mainly at the longest delay condition of 8 s (r = -0.58, p = 0.006). CONCLUSION The present results showed that moderate-high dose of d-amphetamine and moderate dose of caffeine do not directly affect performances on DST or SST. However, the results indicate that d-amphetamine indirectly influences SWM, through its effect on psychosis-like experiences. TRIAL REGISTRATION CLINICAL TRIAL REGISTRATION NUMBER CT-2018-CTN-02561 (Therapeutic Goods Administration Clinical Trial Registry) and ACTRN12618001292268 (The Australian New Zealand Clinical Trials Registry) for caffeine study, and ACTRN12608000610336 for d-amphetamine study.
Collapse
Affiliation(s)
- Faiz M. Kassim
- Psychopharmacology Research Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
- Department of Psychiatry, St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia
| | - J. H. Mark Lim
- Psychopharmacology Research Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Sophie V. Slawik
- Faculty of Human and Health Sciences, Psychology, University of Bremen, Bremen, Germany
| | - Katharina Gaus
- Faculty of Human and Health Sciences, Psychology, University of Bremen, Bremen, Germany
| | - Benjamin Peters
- Department of Psychiatry, St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia
| | - Joseph W. Y. Lee
- Psychiatry, Medical School, University of Western Australia, Perth, WA, Australia
| | - Emily K. Hepple
- Mental Health, North Metropolitan Health Services, Perth, WA, Australia
| | - Jennifer Rodger
- Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, WA, Australia
- Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
| | - Matthew A. Albrecht
- Western Australian Centre for Road Safety Research, School of Psychological Science, University of Western Australa, Crawley, WA, Australia
| | - Mathew T. Martin-Iverson
- Psychopharmacology Research Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| |
Collapse
|
5
|
Zouraraki C, Karamaouna P, Giakoumaki SG. Cognitive Processes and Resting-State Functional Neuroimaging Findings in High Schizotypal Individuals and Schizotypal Personality Disorder Patients: A Systematic Review. Brain Sci 2023; 13:brainsci13040615. [PMID: 37190580 DOI: 10.3390/brainsci13040615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/29/2023] [Accepted: 04/02/2023] [Indexed: 04/07/2023] Open
Abstract
Ample research findings indicate that there is altered brain functioning in the schizophrenia spectrum. Nevertheless, functional neuroimaging findings remain ambiguous for healthy individuals expressing high schizotypal traits and patients with schizotypal personality disorder (SPD). The purpose of this systematic review was to identify patterns of task-related and resting-state neural abnormalities across these conditions. MEDLINE-PubMed and PsycINFO were systematically searched and forty-eight studies were selected. Forty studies assessed healthy individuals with high schizotypal traits and eight studies examined SPD patients with functional neuroimaging techniques (fNIRS; fMRI; Resting-state fMRI). Functional alterations in striatal, frontal and temporal regions were found in healthy individuals with high schizotypal traits. Schizotypal personality disorder was associated with default mode network abnormalities but further research is required in order to better conceive its neural correlates. There was also evidence for functional compensatory mechanisms associated with both conditions. To conclude, the findings suggest that brain dysfunctions are evident in individuals who lie along the subclinical part of the spectrum, further supporting the continuum model for schizophrenia susceptibility. Additional research is required in order to delineate the counterbalancing processes implicated in the schizophrenia spectrum, as this approach will provide promising insights for both conversion and protection from conversion into schizophrenia.
Collapse
Affiliation(s)
- Chrysoula Zouraraki
- Laboratory of Neuropsychology, Department of Psychology, University of Crete, 74100 Rethymno, Greece
- University of Crete Research Center for the Humanities, The Social and Education Sciences (UCRC), University of Crete, Gallos University Campus, 74100 Rethymno, Greece
| | - Penny Karamaouna
- Laboratory of Neuropsychology, Department of Psychology, University of Crete, 74100 Rethymno, Greece
- University of Crete Research Center for the Humanities, The Social and Education Sciences (UCRC), University of Crete, Gallos University Campus, 74100 Rethymno, Greece
| | - Stella G. Giakoumaki
- Laboratory of Neuropsychology, Department of Psychology, University of Crete, 74100 Rethymno, Greece
- University of Crete Research Center for the Humanities, The Social and Education Sciences (UCRC), University of Crete, Gallos University Campus, 74100 Rethymno, Greece
| |
Collapse
|
6
|
Kassim FM, Lahooti SK, Keay EA, Iyyalol R, Rodger J, Albrecht MA, Martin-Iverson MT. Dexamphetamine widens temporal and spatial binding windows in healthy participants. J Psychiatry Neurosci 2023; 48:E90-E98. [PMID: 36918195 PMCID: PMC10019325 DOI: 10.1503/jpn.220149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/28/2022] [Accepted: 11/11/2022] [Indexed: 03/16/2023] Open
Abstract
BACKGROUND The pathophysiology of psychosis is complex, but a better understanding of stimulus binding windows (BWs) could help to improve our knowledge base. Previous studies have shown that dopamine release is associated with psychosis and widened BWs. We can probe BW mechanisms using drugs of specific interest to psychosis. Therefore, we were interested in understanding how manipulation of the dopamine or catecholamine systems affect psychosis and BWs. We aimed to investigate the effect of dexamphetamine, as a dopamine-releasing stimulant, on the BWs in a unimodal illusion: the tactile funneling illusion (TFI). METHODS We conducted a randomized, double-blind, counterbalanced placebo-controlled crossover study to investigate funnelling and errors of localization. We administered dexamphetamine (0.45 mg/kg) to 46 participants. We manipulated 5 spatial (5-1 cm) and 3 temporal (0, 500 and 750 ms) conditions in the TFI. RESULTS We found that dexamphetamine increased funnelling illusion (p = 0.009) and increased the error of localization in a delay-dependent manner (p = 0.03). We also found that dexamphetamine significantly increased the error of localization at 500 ms temporal separation and 4 cm spatial separation (p interaction = 0.009; p 500ms|4cm v. baseline = 0.01). LIMITATIONS Although amphetamine-induced models of psychosis are a useful approach to understanding the physiology of psychosis related to dopamine hyperactivity, dexamphetamine is equally effective at releasing noradrenaline and dopamine, and, therefore, we were unable to tease apart the effects of the 2 systems on BWs in our study. CONCLUSION We found that dexamphetamine increases illusory perception on the unimodal TFI in healthy participants, which suggests that dopamine or other catecholamines have a role in increasing tactile spatial and temporal BWs.
Collapse
Affiliation(s)
- Faiz M Kassim
- From the Department of Psychiatry, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia (Kassim); the Psychopharmacology Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia (Kassim, Lahooti, Keay, Martin-Iverson); the Psychiatry, Graylands Hospital, Mt Claremont, Perth, WA, Australia (Iyyalol); the Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, WA, Australia (Rodger); the Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia (Rodger); the Western Australian Centre for Road Safety Research, School of Psychological Science, University of Western Australia, Perth, WA, Australia (Albrecht)
| | - Samra Krakonja Lahooti
- From the Department of Psychiatry, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia (Kassim); the Psychopharmacology Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia (Kassim, Lahooti, Keay, Martin-Iverson); the Psychiatry, Graylands Hospital, Mt Claremont, Perth, WA, Australia (Iyyalol); the Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, WA, Australia (Rodger); the Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia (Rodger); the Western Australian Centre for Road Safety Research, School of Psychological Science, University of Western Australia, Perth, WA, Australia (Albrecht)
| | - Elizabeth Ann Keay
- From the Department of Psychiatry, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia (Kassim); the Psychopharmacology Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia (Kassim, Lahooti, Keay, Martin-Iverson); the Psychiatry, Graylands Hospital, Mt Claremont, Perth, WA, Australia (Iyyalol); the Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, WA, Australia (Rodger); the Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia (Rodger); the Western Australian Centre for Road Safety Research, School of Psychological Science, University of Western Australia, Perth, WA, Australia (Albrecht)
| | - Rajan Iyyalol
- From the Department of Psychiatry, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia (Kassim); the Psychopharmacology Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia (Kassim, Lahooti, Keay, Martin-Iverson); the Psychiatry, Graylands Hospital, Mt Claremont, Perth, WA, Australia (Iyyalol); the Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, WA, Australia (Rodger); the Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia (Rodger); the Western Australian Centre for Road Safety Research, School of Psychological Science, University of Western Australia, Perth, WA, Australia (Albrecht)
| | - Jennifer Rodger
- From the Department of Psychiatry, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia (Kassim); the Psychopharmacology Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia (Kassim, Lahooti, Keay, Martin-Iverson); the Psychiatry, Graylands Hospital, Mt Claremont, Perth, WA, Australia (Iyyalol); the Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, WA, Australia (Rodger); the Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia (Rodger); the Western Australian Centre for Road Safety Research, School of Psychological Science, University of Western Australia, Perth, WA, Australia (Albrecht)
| | - Matthew A Albrecht
- From the Department of Psychiatry, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia (Kassim); the Psychopharmacology Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia (Kassim, Lahooti, Keay, Martin-Iverson); the Psychiatry, Graylands Hospital, Mt Claremont, Perth, WA, Australia (Iyyalol); the Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, WA, Australia (Rodger); the Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia (Rodger); the Western Australian Centre for Road Safety Research, School of Psychological Science, University of Western Australia, Perth, WA, Australia (Albrecht)
| | - Mathew T Martin-Iverson
- From the Department of Psychiatry, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia (Kassim); the Psychopharmacology Unit, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia (Kassim, Lahooti, Keay, Martin-Iverson); the Psychiatry, Graylands Hospital, Mt Claremont, Perth, WA, Australia (Iyyalol); the Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Crawley, WA, Australia (Rodger); the Brain Plasticity Group, Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia (Rodger); the Western Australian Centre for Road Safety Research, School of Psychological Science, University of Western Australia, Perth, WA, Australia (Albrecht)
| |
Collapse
|
7
|
Kassim FM, Mark Lim JH, Albrecht MA, Martin-Iverson MT. Dexamphetamine influences funneling illusion based on psychometric score. Hum Psychopharmacol 2023; 38:e2862. [PMID: 36799101 DOI: 10.1002/hup.2862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/18/2023]
Abstract
OBJECTIVES Our team previously showed that like the experience of the rubber hand illusion (RHI) in people with schizophrenia and their offspring¸ dexamphetamine administration to healthy volunteers increases the stimulus binding windows (BWs) in RHI. It is not clear if similar expansions of BWs are present for unimodal illusions. Studies have also shown that subjective or objective effects of amphetamine would be linked to between-person variations in personality measures. Therefore, we aimed to examine the effect of dexamphetamine (DEX), a dopamine-releasing stimulant, on illusory perception using unimodal sensory stimuli (Tactile Funneling Illusion [TFI]) across both temporal and spatial variables. We further examined the relationship between changes in psychometric scores and changes in illusion perception induced by dexamphetamine. METHODS Healthy subjects (N = 20) participated in a randomized, double-blind, counter-balanced, placebo-controlled, cross-over study. The effects of dexamphetamine (0.45 mg/kg, PO, q.d.) on funneling and error of spatial localization (EL) were examined using TFI. Psychotomimetic effects were assessed using a battery of psychological measures. RESULTS Dexamphetamine did not significantly increased the funneling illusion (p = 0.88) or EL (p = 0.5), relative to placebo. However, the degree of change in psychometric scores following dexamphetamine positively correlated with changes in funneling (ρ = 0.48, p = 0.03, n = 20), mainly at 0 ms delay condition (ρ = 0.6, p = 0.004, n = 20). CONCLUSION Unlike multimodal illusions, alteration of BWs does not occur for unimodal illusions after administration of a dopamine-releasing agent. However, our findings indicate that moderate release of dopamine, through its psychotomimetic effect, indirectly influences unimodal illusion.
Collapse
Affiliation(s)
- Faiz M Kassim
- Neuropsychopharmacology Research Unit, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - J H Mark Lim
- Neuropsychopharmacology Research Unit, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Matthew A Albrecht
- Western Australian Centre for Road Safety Research, School of Psychological Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - Mathew T Martin-Iverson
- Neuropsychopharmacology Research Unit, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia
| |
Collapse
|
8
|
Kassim FM. Systematic reviews of the acute effects of amphetamine on working memory and other cognitive performances in healthy individuals, with a focus on the potential influence of personality traits. Hum Psychopharmacol 2023; 38:e2856. [PMID: 36251504 PMCID: PMC10078276 DOI: 10.1002/hup.2856] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 02/06/2023]
Abstract
OBJECTIVES This research aimed to systematically review the acute effects of amphetamine (AMP), a dopamine-releasing agent, on working memory (WM) and other cognitive performances. The investigation also aimed to review the impact of personality traits on the subjective and objective effects of AMP and possible links between personality traits and effects of AMP. METHODS Previous double-blind controlled studies assessing the main effects of AMP on WM and other cognitive performances in healthy volunteers were systematically reviewed. An electronic search was performed in the PUBMED and SCOPUS databases. Narrative reviews of the influence of personality traits on the subjective and objective effects of AMP were included. RESULTS Nineteen WM studies were included in the current review. Seven studies found effects of AMP on spatial WM, but only one study found the effect of AMP on verbal WM. Thirty-seven independent studies on other aspects of cognitive performance were identified. Twenty-two reported effects of AMP on cognitive functions. Studies also showed that personality traits are associated with the subjective effects of AMP. However, few studies reported the impacts of personality traits on the objective (such as WM) effects of AMP. CONCLUSION Overall, findings indicate that AMP has mixed-effects on spatial WM and other cognitive functions, but it lacks effects on verbal WM. Although there are insufficient studies on objective measures, studies also indicated that the subjective effects of AMP administration are linked to between-person variations in personality traits.
Collapse
Affiliation(s)
- Faiz M Kassim
- Pharmacology, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, Australia.,Department of Psychiatry, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia
| |
Collapse
|
9
|
Dourron HM, Strauss C, Hendricks PS. Self-Entropic Broadening Theory: Toward a New Understanding of Self and Behavior Change Informed by Psychedelics and Psychosis. Pharmacol Rev 2022; 74:982-1027. [DOI: 10.1124/pharmrev.121.000514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 11/22/2022] Open
|
10
|
Bègue I, Brakowski J, Seifritz E, Dagher A, Tobler PN, Kirschner M, Kaiser S. Cerebellar and cortico-striatal-midbrain contributions to reward-cognition processes and apathy within the psychosis continuum. Schizophr Res 2022; 246:85-94. [PMID: 35728420 DOI: 10.1016/j.schres.2022.06.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/30/2022] [Accepted: 06/11/2022] [Indexed: 11/29/2022]
Abstract
Negative symptoms in the psychosis continuum are linked to impairments in reward processing and cognitive function. Processes at the interface of reward processing and cognition and their relation to negative symptoms remain little studied, despite evidence suggestive of integration in mechanisms and neural circuitry. Here, we investigated brain activation during reward-dependent modulation of working memory (WM) and their relationship to negative symptoms in subclinical and early stages of the psychosis continuum. We included 27 persons with high schizotypal personality traits and 23 patients with first episode psychosis as well as 27 healthy controls. Participants underwent functional magnetic resonance imaging while performing an established 2-back WM task with two reward levels (5 CHF vs. no reward), which allowed us to assess common reward-cognition regions through whole-brain conjunction analyses and to investigate relations with clinical scores of negative symptoms. As expected for behavior, reward facilitated performance while cognitive load diminished it. At the neural level, the conjunction of high reward and high cognitive load contrasts across the psychosis continuum showed increased hemodynamic activity in the thalamus and the cerebellar vermis. During high cognitive load, more severe apathy but not diminished expression in the psychosis continuum was associated with reduced activity in right lateral orbitofrontal cortex, midbrain, posterior vermal cerebellum, caudate and lateral parietal cortex. Our results suggest that hypoactivity in the cerebellar vermis and the cortical-striatal-midbrain-circuitry in the psychosis continuum relates to apathy possibly via impaired flexible cognitive resource allocation for effective goal pursuit.
Collapse
Affiliation(s)
- Indrit Bègue
- Division of Adult Psychiatry, Department of Psychiatry, Geneva University Hospitals, Switzerland.
| | - Janis Brakowski
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland
| | - Erich Seifritz
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland
| | - Alain Dagher
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Philippe N Tobler
- Laboratory for Social and Neural Systems Research, Department of Economics, University of Zurich, Switzerland
| | - Matthias Kirschner
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada; Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland
| | - Stefan Kaiser
- Division of Adult Psychiatry, Department of Psychiatry, Geneva University Hospitals, Switzerland
| |
Collapse
|
11
|
Kállai J, Páll T, Herold R, Tényi T, Zsidó AN. Ambiguous handedness and visuospatial pseudoneglect in schizotypy in physical and computer-generated virtual environments. Sci Rep 2022; 12:12169. [PMID: 35842454 PMCID: PMC9288449 DOI: 10.1038/s41598-022-16454-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/11/2022] [Indexed: 12/04/2022] Open
Abstract
Virtual reality (VR) technology has increased clinical attention in the health care of schizophrenia spectrum disorders in both diagnoses of the symptoms and assessment of schizotypal traits. However, the exact nature of VR-induced positive treatment effect in schizotypy is still unknown. In this study, VR technology was used as a non-invasive neurocognitive trigger to test the asymmetric visuospatial representational instability found in individuals with high schizotypy. The study aimed to reveal the brain functional hemispheric laterality in physical and virtual realities in individuals with schizotypal traits. Fifty-one healthy, right-handed participants (24 males and 27 females) were enrolled through public advertisements. Hemispheric functional asymmetry was measured by the Line Bisection Task (LBT). The results revealed that (a) LBT bias in the physical reality showed a handedness-related leftward pseudoneglect, however, similar handedness-related pseudoneglect in VR has not been found. (b) Comparing LBT bias in physically real and VR environments showed rightward drift in VR environments independently to the degree of handedness. (c) The schizotypy has no association with handedness, however, the cognitive schizotypy is related to the LBT bias. Higher cognitive schizotypy in VR associated with left hemispatial pseudoneglect. In conclusion, schizotypy is associated with ambiguous behavioral and cognitive functional laterality. In individuals with high cognitive schizotypy, the VR environment enhanced the representational articulation of the left hemispace. This effect may be originated from the enhancement of the right hemisphere overactivation and is followed by a lower mental control of the overt behavior.
Collapse
Affiliation(s)
- János Kállai
- Institute of Behavioral Sciences, Medical Faculty University of Pécs, Pécs, Hungary. .,Institute of Behavioral Sciences, Medical School, University of Pécs, 7624 Szigeti Street 12, Pécs, Hungary.
| | - Tamás Páll
- Artistic Research at the University of Applied Arts Vienna, Vienna, Austria
| | - Róbert Herold
- Department of Psychiatry and Psychotherapy, Medical School, University of Pécs, Pécs, Hungary
| | - Tamás Tényi
- Department of Psychiatry and Psychotherapy, Medical School, University of Pécs, Pécs, Hungary
| | - András Norbert Zsidó
- Institute of Psychology, Arts and Sciences Faculty, University of Pécs, Pécs, Hungary
| |
Collapse
|
12
|
Positive schizotypy is associated with amplified mnemonic discrimination and attenuated generalization. Eur Arch Psychiatry Clin Neurosci 2022; 273:447-458. [PMID: 35624200 PMCID: PMC10070292 DOI: 10.1007/s00406-022-01430-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 05/09/2022] [Indexed: 11/03/2022]
Abstract
Tendency to experience inaccurate beliefs alongside perceptual anomalies constitutes positive schizotypal traits in the general population and shows continuity with the positive symptoms of schizophrenia. It has been hypothesized that the positive symptomatology of schizophrenia, and by extension, the odd beliefs and unusual perceptual experiences in the general population, are associated with specific alterations in memory functions. An imbalance between memory generalization and episodic memory specificity has been proposed on several counts; however, the direction of the imbalance is currently unclear. Here, we evaluated the association between positive schizotypy, and memory alterations related to hippocampal computations in a general population sample enriched for positive schizotypy. We found that memory generalization is attenuated while memory specificity is elevated in participants with more pronounced positive schizotypal traits. Our findings show that people who are prone to irrational beliefs and unusual experiences also show measurable alterations in memory and likely have difficulty grasping the global picture and rather be overpowered by fragments of information.
Collapse
|
13
|
Razzak AR, Jahrami H, Husni M, Ali ME, Bagust J. Symptom severity is associated with leftward lateralization upon contextual modulation of visual vertical in patients with schizophrenia. Front Psychiatry 2022; 13:948114. [PMID: 35923447 PMCID: PMC9339704 DOI: 10.3389/fpsyt.2022.948114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/27/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Contextual processing dysfunction in patients with schizophrenia (SCZ) is not uniform and task-dependent. In SCZ, studies on the rod and frame test (RFT), which evaluates contextual modulation of verticality perception, are sparse. A main study that utilized a two-alternative forced choice design for judging rod verticality reported equivalent strength of RFT contextual modulation in healthy controls and SCZ. The current study aims to uncover any potential differences in contextual modulation between controls and SCZ with an adjustment method on a computerized RFT. MATERIALS AND METHODS A total of 17 healthy controls and 15 SCZ aligned an oriented rod to their perceived vertical with a computer mouse under four randomized frame presentations: absent frame, non-tilted (Frame0°), or tilted by 18 degrees leftward (Frame-18°) or rightward (Frame+18°). Rod deviation error was assigned a negative or positive value when aligned leftward or rightward, respectively, of 0°. Signed and absolute errors, the rod and frame effect (RFE), and intra-individual variability (inconsistency) were used for analysis. RESULTS There was no group difference in rod alignment errors or derived measures, except that SCZ displayed greater inconsistency in rod alignment, compared to controls. The negative symptom scale (PANSS-N) scores correlated positively with the variability measure and with unsigned Frame-18° error. CONCLUSIONS Only the variability measure was sensitive enough to distinguish between controls and SCZ. SCZ with more severe negative symptoms had larger variability in rod alignment, probably reflecting a state of indifference. The larger deviation errors only with a leftward tilted frame, as PANSS-N scores increased, may indicate a lateralized attentional abnormality that is correlated with severity of symptoms in SCZ.
Collapse
Affiliation(s)
- Abdul Rima Razzak
- Department of Physiology, College of Medicine and Medical Sciences (CMMS), Arabian Gulf University (AGU), Manama, Bahrain
| | - Haitham Jahrami
- Ministry of Health (MOH), Manama, Bahrain.,Department of Psychiatry, College of Medicine and Medical Sciences (CMMS), Arabian Gulf University (AGU), Manama, Bahrain
| | - Mariwan Husni
- Department of Psychiatry, College of Medicine and Medical Sciences (CMMS), Arabian Gulf University (AGU), Manama, Bahrain.,Northern Ontario School of Medicine University, Ontario, ON, Canada
| | | | - Jeff Bagust
- Faculty of Health and Social Sciences, Bournemouth University, Poole, United Kingdom
| |
Collapse
|
14
|
|
15
|
Alfimova MV, Lezheiko T, Plakunova V, Golimbet V. Relationships between schizotypal features, trait anticipatory and consummatory pleasure, and naturalistic hedonic States. MOTIVATION AND EMOTION 2021. [DOI: 10.1007/s11031-021-09896-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
16
|
Walter EE, Fernandez F, Barkus E. Not all stress is created equal: Acute, not ambient stress, impairs learning in high schizotypes. Psych J 2021; 11:179-193. [PMID: 33915603 DOI: 10.1002/pchj.452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 11/08/2022]
Abstract
Learning from feedback is essential for daily functioning, with factors that impact learning having implications for healthy and clinical populations. Reinforcement learning appears impaired across the psychosis continuum, with deficits reported in patients with psychotic disorders as well as high schizotypes from the general population. Stress can impair learning, and sensitivity to stress is present along the psychosis continuum. The aim of the present study was to understand if stress impairs reinforcement learning in those at the lower end of the psychosis continuum. We investigated both naturalistic stress in everyday life using daily hassles (Study 1: n = 70; 31% male, M age = 22.67 years) and acute psychosocial stress using the Trier Social Stress Test (Study 2: n = 57; 32% male, M age = 22.43 years). In the presence of naturalistic stress, learning did not differ across schizotypes. However, under acute psychosocial stress, high schizotypes experienced impaired learning. Our results suggest trail-and-error learning is robust to the ebbs and flows of everyday stress for high schizotypes; however, acute stress is associated with decrements in learning. This indicates that the magnitude of stressors should be considered when designing cognitive and functional interventions for those along the psychosis continuum.
Collapse
Affiliation(s)
- Emma E Walter
- School of Psychology, University of Wollongong, Wollongong, New South Wales, Australia
| | - Francesca Fernandez
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Emma Barkus
- School of Psychology, University of Wollongong, Wollongong, New South Wales, Australia
| |
Collapse
|
17
|
Schizotypy in Parkinson's disease predicts dopamine-associated psychosis. Sci Rep 2021; 11:759. [PMID: 33437004 PMCID: PMC7804198 DOI: 10.1038/s41598-020-80765-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 12/22/2020] [Indexed: 11/08/2022] Open
Abstract
Psychosis is the most common neuropsychiatric side-effect of dopaminergic therapy in Parkinson’s disease (PD). It is still unknown which factors determine individual proneness to psychotic symptoms. Schizotypy is a multifaceted personality trait related to psychosis-proneness and dopaminergic neurotransmission in healthy subjects. We investigated whether (1) PD patients exhibit lower schizotypy than controls and (2) dopamine-related neuropsychiatric side-effects can be predicted by higher schizotypy. In this cross-sectional study, we used the Oxford-Liverpool Inventory of Feelings and Experiences in 56 PD patients (12 women, mean ± sd age: 61 ± 11 years) receiving their usual dopaminergic medication and 32 age-matched healthy controls (n = 32; 18 women, mean ± sd age: 57 ± 6 years). We further compared schizotypy scores of patients with (n = 18, 32.1%) and without previously experienced psychosis. We found that patients exhibited lower schizotypy than controls. Further, patients with a history of psychosis exhibited higher schizotypy than patients without these symptoms. Using an information theoretic measure and a machine learning approach, we show that schizotypy yields the greatest predictive value for dopamine-associated hallucinations compared to other patient characteristics and disease related factors. Our results indicate an overlap between neural networks associated with schizotypy and the pathophysiology of PD and a relationship between schizotypy and psychotic side-effects of dopaminergic medication.
Collapse
|
18
|
Giakoumaki SG, Karamaouna P, Karagiannopoulou L, Zouraraki C. Self-perceived cognitive lapses and psychological well-being in schizotypy: Generalized and domain-specific associations. Scand J Psychol 2020; 62:134-140. [PMID: 33373062 DOI: 10.1111/sjop.12704] [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: 07/25/2020] [Revised: 11/01/2020] [Accepted: 11/07/2020] [Indexed: 01/22/2023]
Abstract
A critical link between schizotypy and schizophrenia is impoverished cognitive functioning. In the majority of studies, though: (1) cognition is examined with standard neuropsychological tasks; and (2) high-schizotypal individuals are defined according to criteria applied in the respective study sample. Taking these considerations into account, the aims of the present study were to examine: (1) differences between four pre-defined, according to normative criteria, schizotypal (paranoid, negative, disorganized and cognitive-perceptual) and one control groups in self-perceived cognitive lapses; and (2) associations between schizotypal dimensions, self-perceived cognitive lapses and psychological well-being. Two hundred and sixty-one participants were administered the Schizotypal Personality Questionnaire, the Cognitive Failures Questionnaire (CFQ) and the Flourishing Scale, which assesses psychological well-being. Negative schizotypals reported higher scores in almost all CFQ measures compared with the control group (all p values < 0.01) along with poorer psychological well-being compared with the control and the cognitive-perceptual groups (both p values < 0.001). The disorganized group had higher scores in distractibility, blunders and total CFQ scores compared with the control group (all p values < 0.001). High psychological well-being was significantly associated with low negative schizotypy and CFQ blunders along with high cognitive-perceptual schizotypy (all p values < 0.05). To summarize, negative schizotypy is associated with a profile of "generalized" self-perceived cognitive lapses while disorganized schizotypy is characterized by self-perceived cognitive slips that have previously been shown to be mediated by a fronto-parietal network. Although psychological well-being is negatively associated with social-context specific cognitive failures and negative schizotypy, it is positively associated with cognitive-perceptual schizotypy.
Collapse
Affiliation(s)
- Stella G Giakoumaki
- Department of Psychology, Faculty of Social Sciences, University of Crete, Gallos University campus, Rethymno 74100, Crete, Greece
| | - Penny Karamaouna
- Department of Psychology, Faculty of Social Sciences, University of Crete, Gallos University campus, Rethymno 74100, Crete, Greece
| | - Leda Karagiannopoulou
- Department of Psychology, Faculty of Social Sciences, University of Crete, Gallos University campus, Rethymno 74100, Crete, Greece
| | - Chrysoula Zouraraki
- Department of Psychology, Faculty of Social Sciences, University of Crete, Gallos University campus, Rethymno 74100, Crete, Greece
| |
Collapse
|
19
|
Meller T, Ettinger U, Grant P, Nenadić I. The association of striatal volume and positive schizotypy in healthy subjects: intelligence as a moderating factor. Psychol Med 2020; 50:2355-2363. [PMID: 31530329 DOI: 10.1017/s0033291719002459] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Schizotypy, a putative schizophrenia endophenotype, has been associated with brain-structural variations partly overlapping with those in psychotic disorders. Variations in precuneus structure have been repeatedly reported, whereas the involvement of fronto-striatal networks - as in schizophrenia - is less clear. While shared genetic architecture is thought to increase vulnerability to environmental insults, beneficial factors like general intelligence might buffer their effect. METHODS To further investigate the role of fronto-striatal networks in schizotypy, we examined the relationship of voxel- and surface-based brain morphometry and a measure of schizotypal traits (Schizotypal Personality Questionnaire, with subscores Cognitive-Perceptual, Interpersonal, Disorganised) in 115 healthy participants [54 female, mean age (s.d.) = 27.57(8.02)]. We tested intelligence (MWT-B) as a potential moderator. RESULTS We found a positive association of SPQ Cognitive-Perceptual with putamen volume (p = 0.040, FWE peak level-corrected), moderated by intelligence: with increasing IQ, the correlation of SPQ Cognitive-Perceptual and striatal volume decreased (p = 0.022). SPQ Disorganised was positively correlated with precentral volume (p = 0.013, FWE peak level-corrected). In an exploratory analysis (p < 0.001, uncorrected), SPQ total score was positively associated with gyrification in the precuneus and postcentral gyrus, and SPQ Disorganised was negatively associated with gyrification in the inferior frontal gyrus. CONCLUSIONS Our findings support the role of fronto-striatal networks for schizotypal features in healthy individuals, and suggest that these are influenced by buffering factors like intelligence. We conclude that protective factors, like general cognitive capacity, might attenuate the psychosis risk associated with schizotypy. These results endorse the idea of a continuous nature of schizotypy, mirroring similar findings in schizophrenia.
Collapse
Affiliation(s)
- Tina Meller
- Cognitive Neuropsychiatry lab, Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg, Rudolf-Bultmann-Str. 8, 35039Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032Marburg, Germany
| | - Ulrich Ettinger
- Department of Psychology, University of Bonn, Kaiser-Karl-Ring 9, 53111Bonn, Germany
| | - Phillip Grant
- Psychology School, Fresenius University of Applied Sciences, Marienburgstr. 6, 60528Frankfurt am Main, Germany
- Faculty of Life Science Engineering, Technische Hochschule Mittelhessen University of Applied Sciences, Giessen, Germany
| | - Igor Nenadić
- Cognitive Neuropsychiatry lab, Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg, Rudolf-Bultmann-Str. 8, 35039Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032Marburg, Germany
- Marburg University Hospital - UKGM, Rudolf-Bultmann-Str. 8, 35039Marburg, Germany
| |
Collapse
|
20
|
Le TP, Lucas HD, Schwartz EK, Mitchell KR, Cohen AS. Frontal alpha asymmetry in schizotypy: electrophysiological evidence for motivational dysfunction. Cogn Neuropsychiatry 2020; 25:371-386. [PMID: 32873177 DOI: 10.1080/13546805.2020.1813096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Introduction: Schizotypy is defined as personality traits reflecting an underlying risk for schizophrenia-spectrum disorders. As yet, there is a dearth of suitable objective markers for measuring schizotypy. Frontal alpha asymmetry, characterised by reduced left versus right frontal region activity, reflects trait-like diminished approach-related systems and has been found in schizophrenia. Methods: The present study used electroencephalography (EEG) recorded on a consumer-grade mobile headset to examine asymmetric resting-state frontal alpha, beta, and gamma power within the multidimensional schizotypy (e.g. positive, negative, disorganised) during a three-minute "eyes closed" resting period in college undergraduates (n=49). Results: Findings suggest that schizotypy was exclusively related to reduced left versus right-lateralised power in the alpha frequency (8.1-12.9 Hz., R2= .16). Follow-up analysis suggested that positive schizotypy was uniquely associated with increased right alpha activity, indicating increased withdrawal motivation. Conclusions: Frontal asymmetry is a possible ecologically valid objective marker for schizotypy that may be detectable using easily accessible, consumer-grade technology.
Collapse
Affiliation(s)
- Thanh P Le
- Department of Psychology, Louisiana State University, Baton Rouge, LA, USA
| | - Heather D Lucas
- Department of Psychology, Louisiana State University, Baton Rouge, LA, USA
| | - Elana K Schwartz
- Department of Psychology, Louisiana State University, Baton Rouge, LA, USA
| | - Kyle R Mitchell
- Desert Pacific Mental Illness Research, Education, and Clinical Center (MIRECC), La Jolla, CA, USA
| | - Alex S Cohen
- Department of Psychology, Louisiana State University, Baton Rouge, LA, USA
| |
Collapse
|
21
|
Giakoumaki SG, Karagiannopoulou L, Karamaouna P, Zouraraki C, Bitsios P. The association of schizotypal traits with Prepulse Inhibition: a double approach exploration. Cogn Neuropsychiatry 2020; 25:281-293. [PMID: 32539604 DOI: 10.1080/13546805.2020.1779679] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Introduction: According to the fully-dimensional approach, schizotypy is a personality trait present in the population in a continuous manner while the quasi-dimensional approach emphasises its extreme presentations. In this study we examined the relationship between sensorimotor gating, a core risk-index of the schizophrenia-spectrum, and four schizotypal factors in a dimensional-wise and a dichotomising-wise approach. Methods: Two-hundred and eighty-three participants were assessed with the Schizotypal Personality Questionnaire and were tested for Prepulse Inhibition (PPI). Associations between the schizotypal factors and startle measures were examined with stepwise regressions (dimensional-wise approach). Individuals in the lower 20% or the upper 20% for each schizotypal factor were identified and between-group comparisons were conducted (dichotomising-wise approach). Results: We found that with both approaches, only high paranoid or negative schizotypy were associated with reduced PPI. The low negative schizotypy group had prolonged onset and peak latencies, indicating that prolonged stimulus detection accompanies superior sensorimotor gating in this group. Conclusions: The findings suggest that although differentiating the effects of the various schizotypal factors is primary, the approach employed is secondary. The study also adds evidence in the literature supporting PPI as a useful endophenotypic marker of the schizophrenia-spectrum and highlights the contribution of specific aspects of schizotypy.
Collapse
Affiliation(s)
- Stella G Giakoumaki
- Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno, Crete, Greece
| | - Leda Karagiannopoulou
- Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno, Crete, Greece
| | - Penny Karamaouna
- Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno, Crete, Greece
| | - Chrysoula Zouraraki
- Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno, Crete, Greece
| | - Panos Bitsios
- Department of Psychiatry and Behavioural Sciences, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece
| |
Collapse
|
22
|
Le TP, Cowan T, Schwartz EK, Elvevåg B, Holmlund TB, Foltz PW, Barkus E, Cohen AS. The importance of loneliness in psychotic-like symptoms: Data from three studies. Psychiatry Res 2019; 282:112625. [PMID: 31662188 DOI: 10.1016/j.psychres.2019.112625] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/18/2019] [Accepted: 10/18/2019] [Indexed: 12/26/2022]
Abstract
Poor social connection or loneliness is a prominent feature of schizotypy and may exacerbate psychosis risk. Previous studies have examined the inter-relationships between loneliness and psychosis risk, but critically, they have largely been conducted in non-clinical samples or exclusively used laboratory questionnaires with limited consideration of the heterogeneity within schizotypy (i.e., positive, negative, disorganized factors). The present study examined links between loneliness and psychotic-like symptoms across the dimensions of schizotypy through cross-sectional, laboratory-based questionnaires (Study 1; N = 160), ambulatory assessment (Study 2; N = 118) in undergraduates, and ambulatory assessment in inpatients in a substance abuse treatment program (Study 3; N = 48). Trait positive schizotypy consistently predicted cross-sectional and state psychotic-like symptoms. Loneliness, assessed via cross-sectional and ambulatory means, was largely linked with psychotic-like symptoms. Importantly, psychotic-like symptoms were dynamic: psychotic-like symptoms largely increased with loneliness in individuals with elevated positive and disorganized schizotypal traits, though there were some inconsistency related to disorganized schizotypy and state psychotic-like symptoms. Negative schizotypy and loneliness did not significantly interact to predict psychotic-like symptoms, suggesting specificity to positive schizotypy. Ambulatory approaches provide the opportunity for ecologically valid identification of risk states across psychopathology, thus informing early intervention.
Collapse
Affiliation(s)
- Thanh P Le
- Department of Psychology, Louisiana State University, United States.
| | - Tovah Cowan
- Department of Psychology, Louisiana State University, United States
| | - Elana K Schwartz
- Department of Psychology, Louisiana State University, United States
| | - Brita Elvevåg
- Department of Clinical Medicine, University of Tromsø - the Arctic University of Norway, Norway; The Norwegian Centre for eHealth Research, University Hospital of North Norway, Norway
| | - Terje B Holmlund
- Department of Clinical Medicine, University of Tromsø - the Arctic University of Norway, Norway
| | - Peter W Foltz
- Institute of Cognitive Science, University of Colorado, United States
| | - Emma Barkus
- School of Psychology, University of Wollongong, United States
| | - Alex S Cohen
- Department of Psychology, Louisiana State University, United States
| |
Collapse
|
23
|
Rominger C, Fink A, Weiss EM, Schulter G, Perchtold CM, Papousek I. The propensity to perceive meaningful coincidences is associated with increased posterior alpha power during retention of information in a modified Sternberg paradigm. Conscious Cogn 2019; 76:102832. [DOI: 10.1016/j.concog.2019.102832] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 08/23/2019] [Accepted: 09/28/2019] [Indexed: 02/08/2023]
|
24
|
Meller T, Schmitt S, Stein F, Brosch K, Mosebach J, Yüksel D, Zaremba D, Grotegerd D, Dohm K, Meinert S, Förster K, Redlich R, Opel N, Repple J, Hahn T, Jansen A, Andlauer TFM, Forstner AJ, Heilmann-Heimbach S, Streit F, Witt SH, Rietschel M, Müller-Myhsok B, Nöthen MM, Dannlowski U, Krug A, Kircher T, Nenadić I. Associations of schizophrenia risk genes ZNF804A and CACNA1C with schizotypy and modulation of attention in healthy subjects. Schizophr Res 2019; 208:67-75. [PMID: 31076262 DOI: 10.1016/j.schres.2019.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 03/05/2019] [Accepted: 04/20/2019] [Indexed: 12/30/2022]
Abstract
Schizotypy is a multidimensional risk phenotype distributed in the general population, constituting of subclinical, psychotic-like symptoms. It is associated with psychosis proneness, and several risk genes for psychosis are associated with schizotypy in non-clinical populations. Schizotypy might also modulate cognitive abilities as it is associated with attentional deficits in healthy subjects. In this study, we tested the hypothesis that established genetic risk variants ZNF804A rs1344706 and CACNA1C rs1006737 are associated with psychometric schizotypy and that schizotypy mediates their effect on attention or vice versa. In 615 healthy subjects from the FOR2107 cohort study, we analysed the genetic risk variants ZNF804A rs1344706 and CACNA1C rs1006737, psychometric schizotypy (schizotypal personality questionnaire-brief SPQB), and a neuropsychological measure of sustained and selective attention (d2 test). ZNF804A rs1344706 C (non-risk) alleles were significantly associated with higher SPQ-B Cognitive-Perceptual subscores in women and with attention deficits in both sexes. This schizotypy dimension also mediated the effect of ZNF804A on attention in women, but not in men. CACNA1C rs1006737-A showed a significant sex-modulated negative association with Interpersonal schizotypy only in men, and no effect on attention. Our multivariate model demonstrates differential genetic contributions of two psychosis risk genes to dimensions of schizotypy and, partly, to attention. This supports a model of shared genetic influence between schizotypy and cognitive functions impaired in schizophrenia.
Collapse
Affiliation(s)
- Tina Meller
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032 Marburg, Germany.
| | - Simon Schmitt
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032 Marburg, Germany
| | - Frederike Stein
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032 Marburg, Germany
| | - Katharina Brosch
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032 Marburg, Germany
| | - Johannes Mosebach
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany
| | - Dilara Yüksel
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; SRI International, Center for Health Sciences, Bioscience Division, 333 Ravenswood Avenue, 94025 Menlo Park, CA, USA
| | - Dario Zaremba
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Dominik Grotegerd
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Katharina Dohm
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Susanne Meinert
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Katharina Förster
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Ronny Redlich
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Nils Opel
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Jonathan Repple
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Tim Hahn
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Andreas Jansen
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032 Marburg, Germany; Core-Facility BrainImaging, Faculty of Medicine, Philipps-Universität Marburg, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany
| | - Till F M Andlauer
- Max-Planck-Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany; Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Straße 22, 81675 Munich, Germany
| | - Andreas J Forstner
- Institute of Human Genetics, University of Bonn School of Medicine & University Hospital Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany; Institute of Human Genetics, Philipps-Universität Marburg, Baldingerstraße, 35033 Marburg, Germany; Department of Biomedicine, University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland; Institute of Medical Genetics and Pathology, University Hospital Basel, Schönbeinstr. 40, 4056 Basel, Switzerland
| | - Stefanie Heilmann-Heimbach
- Institute of Human Genetics, University of Bonn School of Medicine & University Hospital Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany
| | - Fabian Streit
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany
| | - Stephanie H Witt
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany
| | - Marcella Rietschel
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany
| | - Bertram Müller-Myhsok
- Max-Planck-Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Str. 17, 81377 Munich, Germany; Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK
| | - Markus M Nöthen
- Institute of Human Genetics, University of Bonn School of Medicine & University Hospital Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany
| | - Udo Dannlowski
- Department of Psychiatry and Psychotherapy, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A9, 48149 Münster, Germany
| | - Axel Krug
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032 Marburg, Germany
| | - Tilo Kircher
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032 Marburg, Germany
| | - Igor Nenadić
- Department of Psychiatry and Psychotherapy, Philipps-Universität Marburg and University Hospital Marburg, UKGM, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), Hans-Meerwein-Str. 6, 35032 Marburg, Germany
| |
Collapse
|
25
|
Rössler J, Unterassner L, Wyss T, Haker H, Brugger P, Rössler W, Wotruba D. Schizotypal Traits are Linked to Dopamine-Induced Striato-Cortical Decoupling: A Randomized Double-Blind Placebo-Controlled Study. Schizophr Bull 2019; 45:680-688. [PMID: 29878280 PMCID: PMC6483584 DOI: 10.1093/schbul/sby079] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The dopamine hypothesis of schizophrenia implies that alterations in the dopamine system cause functional abnormalities in the brain that may converge to aberrant salience attribution and eventually lead to psychosis. Indeed, widespread brain disconnectivity across the psychotic spectrum has been revealed by resting-state functional magnetic resonance imaging (rs-fMRI). However, the dopaminergic involvement in intrinsic functional connectivity (iFC) and its putative relationship to the development of psychotic spectrum disorders remains partly unclear-in particular at the low-end of the psychosis continuum. Therefore, we investigated dopamine-induced changes in striatal iFC and their modulation by psychometrically assessed schizotypy. Our randomized, double-blind placebo-controlled study design included 54 healthy, right-handed male participants. Each participant was assessed with the Schizotypal Personality Questionnaire (SPQ) and underwent 10 minutes of rs-fMRI scanning. Participants then received either a placebo or 200 mg of L-DOPA, a dopamine precursor. We analyzed iFC of 6 striatal seeds that are known to evoke modulation of dopamine-related networks. The main effect of L-DOPA was a significant functional decoupling from the right ventral caudate to both occipital fusiform gyri. This dopamine-induced decoupling emerged primarily in participants with low SPQ scores, while participants with high positive SPQ scores showed decoupling indifferently of the L-DOPA challenge. Taken together, these findings demonstrate that schizotypal traits may be the result of dopamine-induced striato-occipital decoupling.
Collapse
Affiliation(s)
- Julian Rössler
- Collegium Helveticum, University of Zurich; and ETH Zurich, Zurich, Switzerland,To whom correspondence should be addressed; Julian Rössler, Institute of Anaesthesiology, University Hospital Zurich, Raemistrasse 100, Zurich 8091, Switzerland; tel: +41 442551111; fax: +41 442554409; e-mail:
| | - Lui Unterassner
- Collegium Helveticum, University of Zurich; and ETH Zurich, Zurich, Switzerland
| | - Thomas Wyss
- Collegium Helveticum, University of Zurich; and ETH Zurich, Zurich, Switzerland
| | - Helene Haker
- Translational Neuromodeling Unit (TNU), Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Peter Brugger
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Wulf Rössler
- Collegium Helveticum, University of Zurich; and ETH Zurich, Zurich, Switzerland,Psychiatric University Hospital, Zürich University, Zürich, Switzerland,Laboratory of Neuroscience (LIM 27), Institute of Psychiatry, University of Sao Paulo, Sao Paulo, Brazil,Department of Psychiatry and Psychotherapy, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany
| | - Diana Wotruba
- Collegium Helveticum, University of Zurich; and ETH Zurich, Zurich, Switzerland
| |
Collapse
|
26
|
Kim HK, Park HY, Seo E, Bang M, Song YY, Lee SY, Kim KR, Park JY, Kang JI, Lee E, An SK. Factors Associated With Psychosocial Functioning and Outcome of Individuals With Recent-Onset Schizophrenia and at Ultra-High Risk for Psychosis. Front Psychiatry 2019; 10:459. [PMID: 31293463 PMCID: PMC6606785 DOI: 10.3389/fpsyt.2019.00459] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 06/11/2019] [Indexed: 01/31/2023] Open
Abstract
Background: Patients with schizophrenia have impairments in social functioning and are readmitted to healthcare institutions frequently. Individuals at ultra-high risk (UHR) for psychosis already present poor social functioning; among those individuals, the conversion rate from the putative prodromal phase to overt psychosis is 20%-30% within 1-2 years. Here, we analyzed the factor structure of self-related variables and neuro- and socio-cognitive function, and investigated whether these factors were associated with psychosocial function and prognostic outcome in individuals with recent-onset schizophrenia (ROSPR) or at UHR for psychosis. Methods: We evaluated 60 individuals at UHR for psychosis, 47 individuals with ROSPR, and 71 healthy controls using a comprehensive neurocognitive test battery and self-reported attribution scales, self-esteem, resilience, aberrant subjective experiences of schizotypy (physical anhedonia, social anhedonia, magical ideation, and perceptual aberration), and basic symptoms. We assessed psychosocial function with the Quality of Life Scale (QLS). Results: Factor analysis of all subjects revealed a four-factor structure comprising social-cognitive bias, reflective self, neurocognition, and pre-reflective self factors. Multiple regression analysis at baseline revealed that the factor structure predicted QLS. In the UHR group, social-cognitive bias, reflective self, neurocognition, and negative symptoms were significant determinants, explaining 38.0% of total QLS score variance. In the ROSPR group, reflective self and negative symptoms were significant determinants, explaining 54.4% of total QLS score variance. During follow-up, 13 individuals at UHR for psychosis developed psychosis (cumulative prevalence: 31.2% ± 7.6% at 6 years), with neurocognition score at baseline remaining a significant predictor of conversion [χ2(1) = 4.009, p = 0.045; hazard ratio 0.56, 95% confidence interval 0.31-0.99, p = 0.048]. Five patients with schizophrenia were (re)admitted during follow-up (cumulative prevalence: 16.1% ± 7.1% at 6 years); no factor was found to predict (re)admission. Conclusion: Factor analysis revealed an intrinsic four-factor structure of social-cognitive bias, reflective self, neurocognition, and pre-reflective self. The four factors were associated with social functioning at baseline and prodrome-to-psychosis conversion during follow-up, indicating the clinical significance of the four-factor structure. These findings provide a framework for understanding schizophrenia.
Collapse
Affiliation(s)
- Hyun Kyu Kim
- Department of Psychiatry, Yonsei University College of Medicine, Severance Hospital, Seoul, South Korea.,Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Hye Yoon Park
- Department of Psychiatry, Yonsei University College of Medicine, Severance Hospital, Seoul, South Korea.,Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Eunchong Seo
- Department of Psychiatry, Yonsei University College of Medicine, Severance Hospital, Seoul, South Korea.,Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Minji Bang
- Department of Psychiatry, CHA Bundang Medical Center, CHA University, Seongnam, South Korea
| | - Yun Young Song
- Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Su Young Lee
- Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Department of Psychiatry, Myongji Hospital, Hanyang University College of Medicine, Goyang, South Korea
| | - Kyung Ran Kim
- Department of Psychiatry, Yonsei University College of Medicine, Severance Hospital, Seoul, South Korea.,Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Jin Young Park
- Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Department of Psychiatry, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, South Korea
| | - Jee In Kang
- Department of Psychiatry, Yonsei University College of Medicine, Severance Hospital, Seoul, South Korea.,Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Eun Lee
- Department of Psychiatry, Yonsei University College of Medicine, Severance Hospital, Seoul, South Korea.,Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Suk Kyoon An
- Department of Psychiatry, Yonsei University College of Medicine, Severance Hospital, Seoul, South Korea.,Section of Self, Affect and Neuroscience, Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Graduate Program in Cognitive Science, Yonsei University, Seoul, South Korea
| |
Collapse
|
27
|
Steiner GZ, Fernandez FM, Coles M, Karamacoska D, Barkus E, Broyd SJ, Solowij N, Watson OT, Chiu CL, Lind JM, Barry RJ. Interrogating the Relationship Between Schizotypy, the Catechol-O-Methyltransferase (COMT) Val158Met Polymorphism, and Neuronal Oscillatory Activity. Cereb Cortex 2018; 29:3048-3058. [DOI: 10.1093/cercor/bhy171] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 06/24/2018] [Indexed: 02/07/2023] Open
Abstract
Abstract
The COMT Val158Met polymorphism affects the availability of synaptic dopamine in the prefrontal cortex and has been widely studied as a genetic risk factor for psychosis. Schizotypy is associated with an increased risk of psychosis, with some studies implicating similar neurobiological mechanisms to schizophrenia. The present study sought to interrogate the link between the COMT Val158Met polymorphism and schizotypy using electroencephalogram (EEG) to identify neurophysiological mechanisms underpinning psychosis risk. Neurotypical (N = 91) adults were genotyped for the COMT Val158Met polymorphism, completed the Schizotypal Personality Questionnaire (SPQ), and had eyes open resting-state EEG recorded for 4 min. SPQ suspiciousness subscale scores were higher for individuals homozygous for Val/Val and Met/Met versus Val/Met genotypes. Delta, theta, alpha-2, beta-1, and beta-2 amplitudes were lower for Val/Val than Met/Met individuals. Lower theta amplitudes were correlated with higher total SPQ scores (P = 0.050), and multiple regression revealed that higher delta, and lower theta and beta-2 amplitudes (but not COMT genotype) best predicted total SPQ scores (P = 0.014). This study demonstrates the importance of COMT genotype in determining trait suspiciousness and EEG oscillatory activity. It also highlights relationships between dopaminergic alterations, EEG and schizotypy that are dissimilar to those observed in schizophrenia.
Collapse
Affiliation(s)
- Genevieve Z Steiner
- NICM Health Research Institute and Translational Health Research Institute (THRI), Western Sydney University, Penrith NSW, Australia
- Brain & Behavior Research Institute and School of Psychology, University of Wollongong, Wollongong NSW, Australia
| | - Francesca M Fernandez
- Faculty of Science, Medicine and Health, University of Wollongong, Wollongong NSW, Australia
- School of Science, Australian Catholic University, Brisbane QLD, Australia
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong NSW, Australia
| | - Madilyn Coles
- NICM Health Research Institute and Translational Health Research Institute (THRI), Western Sydney University, Penrith NSW, Australia
| | - Diana Karamacoska
- NICM Health Research Institute and Translational Health Research Institute (THRI), Western Sydney University, Penrith NSW, Australia
- Brain & Behavior Research Institute and School of Psychology, University of Wollongong, Wollongong NSW, Australia
| | - Emma Barkus
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong NSW, Australia
| | - Samantha J Broyd
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong NSW, Australia
| | - Nadia Solowij
- School of Psychology and Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong NSW, Australia
| | - Owen T Watson
- Faculty of Medicine and Health Sciences, Macquarie University, Macquarie Park NSW, Australia
| | - Christine L Chiu
- Faculty of Medicine and Health Sciences, Macquarie University, Macquarie Park NSW, Australia
| | - Joanne M Lind
- Faculty of Medicine and Health Sciences, Macquarie University, Macquarie Park NSW, Australia
- School of Medicine,Western Sydney University, Penrith NSW, Australia
| | - Robert J Barry
- Brain & Behavior Research Institute and School of Psychology, University of Wollongong, Wollongong NSW, Australia
| |
Collapse
|
28
|
Modinos G, Egerton A, McMullen K, McLaughlin A, Kumari V, Barker GJ, Williams SCR, Zelaya F. Increased resting perfusion of the hippocampus in high positive schizotypy: A pseudocontinuous arterial spin labeling study. Hum Brain Mapp 2018; 39:4055-4064. [PMID: 29885018 PMCID: PMC6174983 DOI: 10.1002/hbm.24231] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/08/2018] [Accepted: 05/15/2018] [Indexed: 12/16/2022] Open
Abstract
Arterial spin labeling (ASL) provides absolute quantification of resting tissue cerebral blood flow (CBF) as an entirely noninvasive approach with good reproducibility. As a result of neurovascular coupling, ASL provides a useful marker of resting neuronal activity. Recent ASL studies in individuals at clinical high risk of psychosis (CHR) have reported increased resting hippocampal perfusion compared with healthy controls. Schizotypy refers to the presence of subclinical psychotic-like experiences in healthy individuals and represents a robust framework to study neurobiological mechanisms involved in the extended psychosis phenotype while avoiding potentially confounding effects of antipsychotic medications or disease comorbidity. Here we applied pseudo-continuous ASL to examine differences in resting CBF in 21 subjects with high positive schizotypy (HS) relative to 22 subjects with low positive schizotypy (LS), as determined by the Oxford and Liverpool Inventory of Feelings and Experiences. Based on preclinical evidence that hippocampal hyperactivity leads to increased activity in mesostriatal dopamine projections, CBF in hippocampus, midbrain, and striatum was assessed. Participants with HS showed higher CBF of the right hippocampus compared to those with LS (p = .031, family-wise error corrected). No differences were detected in the striatum or midbrain. The association between increased hippocampal CBF and HS supports the notion that hippocampal hyperactivity might be a central characteristic of the extended psychosis phenotype, while hyperactivity in subcortical dopamine pathways may only emerge at a higher intensity of psychotic experiences.
Collapse
Affiliation(s)
- Gemma Modinos
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.,Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Alice Egerton
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Katrina McMullen
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Anna McLaughlin
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Veena Kumari
- Department of Psychology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.,Centre for Cognitive Neuroscience, College of Health and Life Sciences, Brunel University London, London, United Kingdom
| | - Gareth J Barker
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Steve C R Williams
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Fernando Zelaya
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| |
Collapse
|
29
|
Atbasoglu EC, Gumus-Akay G, Guloksuz S, Saka MC, Ucok A, Alptekin K, Gullu S, van Os J. Higher schizotypy predicts better metabolic profile in unaffected siblings of patients with schizophrenia. Psychopharmacology (Berl) 2018; 235:1029-1039. [PMID: 29306964 DOI: 10.1007/s00213-017-4818-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/20/2017] [Indexed: 12/19/2022]
Abstract
RATIONALE Type 2 diabetes (T2D) is more frequent in schizophrenia (Sz) than in the general population. This association is partly accounted for by shared susceptibility genetic variants. OBJECTIVE We tested the hypotheses that a genetic predisposition to Sz would be associated with higher likelihood of insulin resistance (IR), and that IR would be predicted by subthreshold psychosis phenotypes. METHODS Unaffected siblings of Sz patients (n = 101) were compared with a nonclinical sample (n = 305) in terms of IR, schizotypy (SzTy), and a behavioural experiment of "jumping to conclusions". The measures, respectively, were the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Structured Interview for Schizotypy-Revised (SIS-R), and the Beads Task (BT). The likelihood of IR was examined in multiple regression models that included sociodemographic, metabolic, and cognitive parameters alongside group status, SIS-R scores, and BT performance. RESULTS Insulin resistance was less frequent in siblings (31.7%) compared to controls (43.3%) (p < 0.05), and negatively associated with SzTy, as compared among the tertile groups for the latter (p < 0.001). The regression model that examined all relevant parameters included the tSzTy tertiles, TG and HDL-C levels, and BMI, as significant predictors of IR. Lack of IR was predicted by the highest as compared to the lowest SzTy tertile [OR (95%CI): 0.43 (0.21-0.85), p = 0.015]. CONCLUSION Higher dopaminergic activity may contribute to both schizotypal features and a favourable metabolic profile in the same individual. This is compatible with dopamine's regulatory role in glucose metabolism via indirect central actions and a direct action on pancreatic insulin secretion. The relationship between dopaminergic activity and metabolic profile in Sz must be examined in longitudinal studies with younger unaffected siblings.
Collapse
Affiliation(s)
- E Cem Atbasoglu
- Faculty of Medicine, Department of Psychiatry, Ankara University, Ankara, Turkey.
| | | | - Sinan Guloksuz
- Maastricht University Medical Centre, Maastricht, Netherlands
| | - Meram Can Saka
- Faculty of Medicine, Department of Psychiatry, Ankara University, Ankara, Turkey
| | - Alp Ucok
- Istanbul Faculty of Medicine, Department of Psychiatry, Istanbul University, Istanbul, Turkey
| | - Koksal Alptekin
- Faculty of Medicine, Department of Psychiatry, Dokuz Eylul University, İzmir, Turkey
| | - Sevim Gullu
- Faculty of Medicine, Department of Endocrinology and Metabolic Diseases, Ankara University, Ankara, Turkey
| | - Jim van Os
- Maastricht University Medical Centre, Maastricht, Netherlands.,Brain Centre Rudolf Magnus, Utrecht University Medical Centre, Utrecht, Netherlands.,King's College London, Department of Psychosis Studies, Institute of Psychiatry, London, UK
| |
Collapse
|
30
|
Paparelli A, Iwata K, Wakuda T, Iyegbe C, Murray RM, Takei N. Perinatal Asphyxia in Rat Alters Expression of Novel Schizophrenia Risk Genes. Front Mol Neurosci 2017; 10:341. [PMID: 29163023 PMCID: PMC5663725 DOI: 10.3389/fnmol.2017.00341] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/06/2017] [Indexed: 11/17/2022] Open
Abstract
Epidemiological studies suggest that obstetric complications, particularly those related to hypoxia during labor and delivery, are a risk factor for development of schizophrenia. The impact of perinatal asphyxia on postnatal life has been studied in a rodent model of global hypoxia, which is accompanied by cesarean section birth. This asphyxia model shows several behavioral, pharmacological, neurochemical, and neuroanatomical abnormalities in adulthood that have relevance to schizophrenia. Further, it is suggested that schizophrenia has a strong genetic component, and indeed novel candidate genes were recently identified by a genome-wide association study. Here, we examined alteration in the novel schizophrenia risk genes, CNNM2, CSMD1, and MMP16 in the brains of rats undergoing cesarean section with or without global hypoxia. The brain regions studied were the prefrontal cortex, striatum, and hippocampus, which are all relevant to schizophrenia. Risk gene expression was measured at three time periods: neonatal, adolescence, and adulthood. We also performed an in vitro analysis to determine involvement of these genes in CNS maturation during differentiation of human neuronal and glial cell lines. Cnnm2 expression was altered in the brains of asphyxia model rats. However, Csmd1 and Mmp16 showed altered expression by exposure to cesarean section only. These findings suggest that altered expression of these risk genes via asphyxia and cesarean section may be associated, albeit through distinct pathways, with the pathobiology of schizophrenia.
Collapse
Affiliation(s)
- Alessandra Paparelli
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, United Kingdom
| | - Keiko Iwata
- Research Center for Child Mental Development, University of Fukui, Fukui, Japan.,Department of Biology, University of Padova, Padova, Italy
| | - Tomoyasu Wakuda
- Department of Psychiatry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Conrad Iyegbe
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, United Kingdom
| | - Robin M Murray
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, United Kingdom
| | - Nori Takei
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, United Kingdom.,Division of Neuropsychological Development and Health Sciences, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Hamamatsu, Japan.,Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu, Japan
| |
Collapse
|
31
|
Wang Y, Ettinger U, Meindl T, Chan RCK. Association of schizotypy with striatocortical functional connectivity and its asymmetry in healthy adults. Hum Brain Mapp 2017; 39:288-299. [PMID: 29024192 DOI: 10.1002/hbm.23842] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 09/10/2017] [Accepted: 10/02/2017] [Indexed: 01/22/2023] Open
Abstract
Altered striatocortical functional connectivity has been suggested to be a trait marker of schizophrenia spectrum disorders, including schizotypal personality. In the present study, we examined the association between schizotypal personality traits and striatocortical functional connectivity in a sample of healthy adults. The German version of the Schizotypal Personality Questionnaire was obtained from N = 111 participants recruited from the general public. Resting-state functional magnetic resonance imaging scans were acquired at 3T. Six striatal seed regions in each hemisphere were defined and striatocortical resting-state functional connectivity (rsFC) as well as its lateralization indices was calculated. Regression analysis showed that schizotypy scores, especially from the positive dimension, were positively correlated with rsFC between ventral striatum and frontal cortex and negatively associated with rsFC between dorsal striatum and posterior cingulate. No significant associations were found between negative dimension schizotypy and striatocortical rsFC. We also found positive correlations between schizotypy total scores and lateralization index of right dorsal caudate and right rostral putamen. In conclusion, the present study extends previous evidence of altered striatocortical rsFC in the schizophrenia spectrum. The observed associations resemble in part the alterations observed in psychotic patients and their relatives, providing support for dimensionality from schizotypal personality to the clinical disorder. Hum Brain Mapp 39:288-299, 2018. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yi Wang
- Neuropsychology and Applied Cognitive Neuroscience (NACN) Lab, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China
| | | | - Thomas Meindl
- Institute of Clinical Radiology, University of Munich, Munich, Germany
| | - Raymond C K Chan
- Neuropsychology and Applied Cognitive Neuroscience (NACN) Lab, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
32
|
Kapfhammer HP. [The concept of schizoidia in psychiatry : From schizoidia to schizotypy and cluster A personality disorders]. NEUROPSYCHIATRIE : KLINIK, DIAGNOSTIK, THERAPIE UND REHABILITATION : ORGAN DER GESELLSCHAFT ÖSTERREICHISCHER NERVENÄRZTE UND PSYCHIATER 2017; 31:155-171. [PMID: 28699102 DOI: 10.1007/s40211-017-0237-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 06/26/2017] [Indexed: 10/19/2022]
Abstract
From a perspective of conceptual evolution schizoidia was initially considered to describe features both of the premorbid personality of schizophrenic patients and of the personalities of non-psychotic family members (Bleuler, Kahlbaum, Kraepelin). On a psychopatholocial level a close link to the complex basic symptom of autism was stressed. From the very beginnings of modern psychiatry schizoidia was discussed within a conceptual frame of schizophrenia spectrum disorders (Kretschmer, Hoch, Polatin). Approaches to operationalize these conceptual works laid the basis for the cluster A personalities in DSM-III. Due to the prominent concept of schizotypy (Kety, Rado, Meehl) three split up diagnostic categories of schizotypal, schizoid and paranoid personality disorders resulted. Cluster A personality disorders are frequent in community-based epidemiological studies. Health-care seeking behaviour due to primary personality-related problems, however, seems to be less paramount compared to cluster B and C personality disorders. Many family- and twin-based genetic studies convincingly stress a close link between schizotypal personality disorder and schizophrenia. This link is less pronounced for paranoid personality disorder, and even vanishingly low for schizoid personality disorder. From a perspective of schizophrenia spectrum disorders a vast amount of data from molecular genetic, neurobiological, neuropsychological and psychosocial research has impressingly confirmed this link for schizotypal personality disorder. Major research deficits, however, have to be noticed for paranoid and schizoid personality disorder.
Collapse
Affiliation(s)
- Hans-Peter Kapfhammer
- Klinik für Psychiatrie und Psychotherapeutische Medizin, Medizinische Universität Graz, Auenbruggerplatz 31, 8036, Graz, Österreich.
| |
Collapse
|
33
|
Eren F, Dilbaz N, Önder Sönmez E, Turan Ö, Gündüz N, Turan H. Evaluation of the effect of schizotypy on cannabis use predictors. PSYCHIAT CLIN PSYCH 2017. [DOI: 10.1080/24750573.2017.1343224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Fatma Eren
- Araklı State Hospital/Psychiatry Clinic, Trabzon, Turkey
| | - Nesrin Dilbaz
- Üsküdar University Human and Society Sciences Faculty, İstanbul, Turkey
| | | | - Ömer Turan
- Haydarpaşa Numune Training and Research Hospital, İstanbul, Turkey
| | - Nermin Gündüz
- Erzurum Region Training and Research Hospital, Erzurum, Turkey
| | - Hatice Turan
- Moodist Psychiatry and Neurology Hospital, İstanbul, Turkey
| |
Collapse
|
34
|
The Role of Dopamine in Anticipatory Pursuit Eye Movements: Insights from Genetic Polymorphisms in Healthy Adults. eNeuro 2017; 3:eN-NWR-0190-16. [PMID: 28101524 PMCID: PMC5223055 DOI: 10.1523/eneuro.0190-16.2016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 12/12/2022] Open
Abstract
There is a long history of eye movement research in patients with psychiatric diseases for which dysfunctions of neurotransmission are considered to be the major pathologic mechanism. However, neuromodulation of oculomotor control is still hardly understood. We aimed to investigate in particular the impact of dopamine on smooth pursuit eye movements. Systematic variability in dopaminergic transmission due to genetic polymorphisms in healthy subjects offers a noninvasive opportunity to determine functional associations. We measured smooth pursuit in 110 healthy subjects genotyped for two well-documented polymorphisms, the COMT Val158Met polymorphism and the SLC6A3 3′-UTR-VNTR polymorphism. Pursuit paradigms were chosen to particularly assess the ability of the pursuit system to initiate tracking when target motion onset is blanked, reflecting the impact of extraretinal signals. In contrast, when following a fully visible target sensory, retinal signals are available. Our results highlight the crucial functional role of dopamine for anticipatory, but not for sensory-driven, pursuit processes. We found the COMT Val158Met polymorphism specifically associated with anticipatory pursuit parameters, emphasizing the dominant impact of prefrontal dopamine activity on complex oculomotor control. In contrast, modulation of striatal dopamine activity by the SLC6A3 3′-UTR-VNTR polymorphism had no significant functional effect. Though often neglected so far, individual differences in healthy subjects provide a promising approach to uncovering functional mechanisms and can be used as a bridge to understanding deficits in patients.
Collapse
|
35
|
Rabella M, Grasa E, Corripio I, Romero S, Mañanas MÀ, Antonijoan RM, Münte TF, Pérez V, Riba J. Neurophysiological evidence of impaired self-monitoring in schizotypal personality disorder and its reversal by dopaminergic antagonism. NEUROIMAGE-CLINICAL 2016; 11:770-779. [PMID: 27330977 PMCID: PMC4909819 DOI: 10.1016/j.nicl.2016.05.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/26/2016] [Accepted: 05/31/2016] [Indexed: 12/27/2022]
Abstract
Background Schizotypal personality disorder (SPD) is a schizophrenia-spectrum disorder characterized by odd or bizarre behavior, strange speech, magical thinking, unusual perceptual experiences, and social anhedonia. Schizophrenia proper has been associated with anomalies in dopaminergic neurotransmission and deficits in neurophysiological markers of self-monitoring, such as low amplitude in cognitive event-related brain potentials (ERPs) like the error-related negativity (ERN), and the error positivity (Pe). These components occur after performance errors, rely on adequate fronto-striatal function, and are sensitive to dopaminergic modulation. Here we postulated that analogous to observations in schizophrenia, SPD individuals would show deficits in self-monitoring, as measured by the ERN and the Pe. We also assessed the capacity of dopaminergic antagonists to reverse these postulated deficits. Methods We recorded the electroencephalogram (EEG) from 9 SPD individuals and 12 healthy controls in two separate experimental sessions while they performed the Eriksen Flanker Task, a classical task recruiting behavioral monitoring. Participants received a placebo or 1 mg risperidone according to a double-blind randomized design. Results After placebo, SPD individuals showed slower reaction times to hits, longer correction times following errors and reduced ERN and Pe amplitudes. While risperidone impaired performance and decreased ERN and Pe in the control group, it led to behavioral improvements and ERN amplitude increases in the SPD individuals. Conclusions These results indicate that SPD individuals show deficits in self-monitoring analogous to those in schizophrenia. These deficits can be evidenced by neurophysiological measures, suggest a dopaminergic imbalance, and can be reverted by dopaminergic antagonists.
Collapse
Affiliation(s)
- Mireia Rabella
- Servei de Psiquiatria, Hospital de la Santa Creu i Sant Pau, C/SantAntoniMaría Claret, 167, 08025 Barcelona, Spain; Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona 167, 08025 Barcelona, Spain
| | - Eva Grasa
- Servei de Psiquiatria, Hospital de la Santa Creu i Sant Pau, C/SantAntoniMaría Claret, 167, 08025 Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain
| | - Iluminada Corripio
- Servei de Psiquiatria, Hospital de la Santa Creu i Sant Pau, C/SantAntoniMaría Claret, 167, 08025 Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain
| | - Sergio Romero
- Biomedical Engineering Research Centre (CREB), Department of Automatic Control (ESAII), UniversitatPolitècnica de Catalunya (UPC), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain
| | - Miquel Àngel Mañanas
- Biomedical Engineering Research Centre (CREB), Department of Automatic Control (ESAII), UniversitatPolitècnica de Catalunya (UPC), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain; Barcelona College of Industrial Engineering (EUETIB), Universitat Politècnica de Catalunya (UPC), Barcelona 08028, Spain
| | - Rosa Mª Antonijoan
- Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain; Centre d'Investigació de Medicaments, Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona 167, 08025 Barcelona, Spain
| | - Thomas F Münte
- Dept. of Neurology, University of Lübeck, Germany; Institute of Psychology II, University of Lübeck, Germany
| | - Víctor Pérez
- Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain; Institut de Neuropsiquiatria i Addiccions, Hospital del Mar, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; Departament de Psiquiatria, Univ Autonoma de Barcelona, Spain
| | - Jordi Riba
- Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Spain; Centre d'Investigació de Medicaments, Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona 167, 08025 Barcelona, Spain; Human Neuropsychopharmacology Research Group. Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Sant Antoni María Claret, 167, 08025 Barcelona, Spain.
| |
Collapse
|
36
|
Delvecchio G, Bellani M, Altamura AC, Brambilla P. The association between the serotonin and dopamine neurotransmitters and personality traits. Epidemiol Psychiatr Sci 2016; 25:109-12. [PMID: 26750396 PMCID: PMC6998595 DOI: 10.1017/s2045796015001146] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/12/2015] [Indexed: 12/27/2022] Open
Abstract
Evidence from previous studies has reported that complex traits, including psychiatric disorders, are moderately to highly heritable. Moreover, it has also been shown that specific personality traits may increase the risk to develop mental illnesses. Therefore the focus of the research shifted towards the identification of the biological mechanisms underpinning these traits by exploring the effects of a constellation of genetic polymorphisms in healthy subjects. Indeed, studying the effect of genetic variants in normal personality provides a unique means for identifying candidate genes which may increase the risk for psychiatric disorders. In this review, we discuss the impact of two of the most frequently studied genetic polymorphisms on personality in healthy subjects, the 5-HTT polymorphism of the serotonin transporter and the DRD2/DRD4 polymorphisms of the D2/D4 dopamine's receptors. The main aims are: (a) to highlight that the study of candidate genes provides a fruitful ground for the identification of the biological underpinnings of personality without, though, reaching a general consensus about the strength of this relationship; and (b) to outline that the research in personality genetics should be expanded to provide a clearer picture of the heritability of personality traits.
Collapse
Affiliation(s)
- G. Delvecchio
- IRCCS ‘E. Medea’ Scientific Institute, Bosisio Parini, Italy
| | - M. Bellani
- Department of Public Health and Community Medicine, Inter University Centre for Behavioural Neurosciences, University of Verona, Verona, Italy
| | - A. C. Altamura
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - P. Brambilla
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
- Department of Psychiatry and Behavioural Neurosciences, University of Texas at Houston, TX, USA
| |
Collapse
|
37
|
Polner B, Moustafa AA, Nagy H, Takáts A, Győrfi O, Kéri S. Dopamine improves exploration after expectancy violations and induces psychotic-like experiences in patients with Parkinson’s disease. Neurosci Lett 2016; 616:132-7. [DOI: 10.1016/j.neulet.2016.01.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/24/2015] [Accepted: 01/21/2016] [Indexed: 01/09/2023]
|
38
|
Zabelina DL, Colzato L, Beeman M, Hommel B. Dopamine and the Creative Mind: Individual Differences in Creativity Are Predicted by Interactions between Dopamine Genes DAT and COMT. PLoS One 2016; 11:e0146768. [PMID: 26783754 PMCID: PMC4718590 DOI: 10.1371/journal.pone.0146768] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 12/22/2015] [Indexed: 01/20/2023] Open
Abstract
The dopaminergic (DA) system may be involved in creativity, however results of past studies are mixed. We attempted to clarify this putative relation by considering the mediofrontal and the nigrostriatal DA pathways, uniquely and in combination, and their contribution to two different measures of creativity–an abbreviated version of the Torrance Test of Creative Thinking, assessing divergent thinking, and a real-world creative achievement index. We found that creativity can be predicted from interactions between genetic polymorphisms related to frontal (COMT) and striatal (DAT) DA pathways. Importantly, the Torrance test and the real-world creative achievement index related to different genetic patterns, suggesting that these two measures tap into different aspects of creativity, and depend on distinct, but interacting, DA sub-systems. Specifically, we report that successful performance on the Torrance test is linked with dopaminergic polymorphisms associated with good cognitive flexibility and medium top-down control, or with weak cognitive flexibility and strong top-down control. The latter is particularly true for the originality factor of divergent thinking. High real-world creative achievement, on the other hand, as assessed by the Creative Achievement Questionnaire, is linked with dopaminergic polymorphisms associated with weak cognitive flexibility and weak top-down control. Taken altogether, our findings support the idea that human creativity relies on dopamine, and on the interaction between frontal and striatal dopaminergic pathways in particular. This interaction may help clarify some apparent inconsistencies in the prior literature, especially if the genes and/or creativity measures were analyzed separately.
Collapse
Affiliation(s)
- Darya L. Zabelina
- Medical Social Sciences, Northwestern University, Chicago, IL, United States of America
- * E-mail:
| | - Lorenza Colzato
- Leiden University, Institute for Psychological Research & Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Mark Beeman
- Psychology Department, Northwestern University, Evanston, IL, United States of America
| | - Bernhard Hommel
- Leiden University, Institute for Psychological Research & Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| |
Collapse
|
39
|
Ettinger U, Merten N, Kambeitz J. Meta-analysis of the association of the SLC6A3 3'-UTR VNTR with cognition. Neurosci Biobehav Rev 2015; 60:72-81. [PMID: 26593110 DOI: 10.1016/j.neubiorev.2015.09.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/04/2015] [Accepted: 09/24/2015] [Indexed: 12/19/2022]
Abstract
The gene coding for the dopamine transporter (DAT), SLC6A3, contains a 40-base pair variable number of tandem repeats (VNTR) polymorphism (rs28363170) in its 3' untranslated region. This VNTR has been associated with attention deficit hyperactivity disorder (ADHD) and has been investigated in relation to cognition and brain function. Here, we report the results of a comprehensive meta-analysis with meta-regression examining the association of the VNTR with different domains of cognition in healthy adults. We extracted data from 28 independent studies and carried out meta-analyses for associations with working memory (k=10 samples, N=1193 subjects), inhibition (k=8 samples, N=829 subjects), executive functions including inhibition (k=10 samples, N=984 subjects), attention (k=6 samples, N=742 subjects) and declarative long-term memory (k=5 samples, N=251 subjects). None of the investigated dimensions showed significant associations with the VNTR (all p>0.26). Meta-regression including year of publication, gender, age, ethnicity and percentage of 10R-homozygotes similarly did not attain significance. We conclude that there is no evidence that rs28363170 may be a significant predictor of cognitive function in healthy adults.
Collapse
Affiliation(s)
- Ulrich Ettinger
- Department of Psychology, University of Bonn, Bonn, Germany.
| | | | - Joseph Kambeitz
- Department of Psychiatry, University of Munich, Munich, Germany
| |
Collapse
|
40
|
Schmack K, Rössler H, Sekutowicz M, Brandl EJ, Müller DJ, Petrovic P, Sterzer P. Linking unfounded beliefs to genetic dopamine availability. Front Hum Neurosci 2015; 9:521. [PMID: 26483654 PMCID: PMC4588007 DOI: 10.3389/fnhum.2015.00521] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 09/07/2015] [Indexed: 12/17/2022] Open
Abstract
Unfounded convictions involving beliefs in the paranormal, grandiosity ideas or suspicious thoughts are endorsed at varying degrees among the general population. Here, we investigated the neurobiopsychological basis of the observed inter-individual variability in the propensity toward unfounded beliefs. One hundred two healthy individuals were genotyped for four polymorphisms in the COMT gene (rs6269, rs4633, rs4818, and rs4680, also known as val158met) that define common functional haplotypes with substantial impact on synaptic dopamine degradation, completed a questionnaire measuring unfounded beliefs, and took part in a behavioral experiment assessing perceptual inference. We found that greater dopamine availability was associated with a stronger propensity toward unfounded beliefs, and that this effect was statistically mediated by an enhanced influence of expectations on perceptual inference. Our results indicate that genetic differences in dopaminergic neurotransmission account for inter-individual differences in perceptual inference linked to the formation and maintenance of unfounded beliefs. Thus, dopamine might be critically involved in the processes underlying one's interpretation of the relationship between the self and the world.
Collapse
Affiliation(s)
- Katharina Schmack
- Department of Psychiatry, Charité Campus Mitte, Charité Universitätsmedizin Berlin Berlin, Germany
| | - Hannes Rössler
- Department of Psychiatry, Charité Campus Mitte, Charité Universitätsmedizin Berlin Berlin, Germany
| | - Maria Sekutowicz
- Department of Psychiatry, Charité Campus Mitte, Charité Universitätsmedizin Berlin Berlin, Germany
| | - Eva J Brandl
- Department of Psychiatry, Charité Campus Mitte, Charité Universitätsmedizin Berlin Berlin, Germany
| | - Daniel J Müller
- Neurogenetics Section, Centre for Addiction and Mental Health Toronto, ON, Canada
| | - Predrag Petrovic
- Department of Clinical Neuroscience, Karolinska Institutet Stockholm, Sweden
| | - Philipp Sterzer
- Department of Psychiatry, Charité Campus Mitte, Charité Universitätsmedizin Berlin Berlin, Germany
| |
Collapse
|
41
|
Ettinger U, Mohr C, Gooding DC, Cohen AS, Rapp A, Haenschel C, Park S. Cognition and brain function in schizotypy: a selective review. Schizophr Bull 2015; 41 Suppl 2:S417-26. [PMID: 25810056 PMCID: PMC4373634 DOI: 10.1093/schbul/sbu190] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Schizotypy refers to a set of personality traits thought to reflect the subclinical expression of the signs and symptoms of schizophrenia. Here, we review the cognitive and brain functional profile associated with high questionnaire scores in schizotypy. We discuss empirical evidence from the domains of perception, attention, memory, imagery and representation, language, and motor control. Perceptual deficits occur early and across various modalities. While the neural mechanisms underlying visual impairments may be linked to magnocellular dysfunction, further effects may be seen downstream in higher cognitive functions. Cognitive deficits are observed in inhibitory control, selective and sustained attention, incidental learning, and memory. In concordance with the cognitive nature of many of the aberrations of schizotypy, higher levels of schizotypy are associated with enhanced vividness and better performance on tasks of mental rotation. Language deficits seem most pronounced in higher-level processes. Finally, higher levels of schizotypy are associated with reduced performance on oculomotor tasks, resembling the impairments seen in schizophrenia. Some of these deficits are accompanied by reduced brain activation, akin to the pattern of hypoactivations in schizophrenia spectrum individuals. We conclude that schizotypy is a construct with apparent phenomenological overlap with schizophrenia and stable interindividual differences that covary with performance on a wide range of perceptual, cognitive, and motor tasks known to be impaired in schizophrenia. The importance of these findings lies not only in providing a fine-grained neurocognitive characterization of a personality constellation known to be associated with real-life impairments, but also in generating hypotheses concerning the aetiology of schizophrenia.
Collapse
Affiliation(s)
- Ulrich Ettinger
- Department of Psychology, University of Bonn, Bonn, Germany;
| | - Christine Mohr
- Institute of Psychology, University of Lausanne, Lausanne, Switzerland
| | - Diane C. Gooding
- Department of Psychology and,Department of Psychiatry, University of Wisconsin-Madison, Madison, WI
| | - Alex S. Cohen
- Department of Psychology, Louisiana State University, Baton Rouge, LA
| | - Alexander Rapp
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | | | - Sohee Park
- Department of Psychology, Vanderbilt University, Nashville, TN
| |
Collapse
|
42
|
Gurvich C, Rossell SL. Editorial: Cognition Across the Psychiatric Disorder Spectrum: From Mental Health to Clinical Diagnosis. Front Psychiatry 2015; 6:110. [PMID: 26300789 PMCID: PMC4523700 DOI: 10.3389/fpsyt.2015.00110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/17/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- Caroline Gurvich
- Monash Alfred Psychiatry Research Centre (MAPrc), The Alfred Hospital, Central Clinical School, Monash University , Melbourne, VIC , Australia
| | - Susan L Rossell
- Monash Alfred Psychiatry Research Centre (MAPrc), The Alfred Hospital, Central Clinical School, Monash University , Melbourne, VIC , Australia ; Faculty of Health, Arts and Design, Brain and Psychological Sciences Research Centre, Swinburne University of Technology , Melbourne, VIC , Australia
| |
Collapse
|