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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.
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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
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Karabanowicz E, Tyburski E, Karasiewicz K, Sokołowski A, Mak M, Folkierska-Żukowska M, Radziwiłłowicz W. Metaphor Processing Dysfunctions in Schizophrenia Patients With and Without Substance Use Disorders. Front Psychiatry 2020; 11:331. [PMID: 32390887 PMCID: PMC7193109 DOI: 10.3389/fpsyt.2020.00331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/02/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Patients with schizophrenia have difficulties comprehending metaphors, which significantly impedes communication. However, this topic has not been thoroughly studied in people with a dual diagnosis. On this basis, we formulated two research aims: a) to compare the ability to comprehend metaphors in schizophrenia patients without (SZ) and with substance use disorder (SZ-SUD) and b) to determine the relationship between the processing of metaphorical content and the severity of psychopathological symptoms in both clinical groups. METHODS A total of 40 individuals with SZ and 40 individuals with SZ-SUD took part in the study. The control group was composed of 40 individuals without a psychiatric or neurological diagnosis. Four subtests from the Right Hemisphere Language Battery (Picture Metaphor Test, Written Metaphor Test, Picture Metaphor Explanation Test, Written Metaphor Explanation Test) were used to measure the ability to understand and explain metaphors. RESULTS Both groups of individuals with schizophrenia (SZ and SZ-SUD) scored lower than individuals from the control group on all tests of metaphor processing. However, no differences were observed between the two clinical groups. SZ-SUD patients had better results for Picture Metaphor Explanation than for Written Metaphor Explanation. Negative symptoms were found to be significant predictors of difficulties with understanding and explaining metaphors. CONCLUSION Individuals with schizophrenia, regardless of their substance use disorder (SUD) status, exhibit impaired metaphorical content processing. SUD in schizophrenia is not associated with significant impairments in understanding and explaining metaphorical content. Moreover, impairments in processing metaphorical content are associated with more severe negative symptoms of schizophrenia.
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Affiliation(s)
- Ewa Karabanowicz
- Institute of Psychology, University of Szczecin, Szczecin, Poland
| | - Ernest Tyburski
- Institute of Psychology, SWPS University of Social Sciences and Humanities, Poznan, Poland
| | | | - Andrzej Sokołowski
- Department of Neurology, Memory and Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - Monika Mak
- Independent Clinical Psychology Unit, Pomeranian Medical University, Szczecin, Poland
| | - Monika Folkierska-Żukowska
- Interdisciplinary Centre for Behavioural Genetics Research, Faculty of Psychology, University of Warsaw, Warsaw, Poland
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Power BD, Dragovic M, Badcock JC, Morgan VA, Castle D, Jablensky A, Stefanis NC. No additive effect of cannabis on cognition in schizophrenia. Schizophr Res 2015; 168:245-51. [PMID: 26235754 DOI: 10.1016/j.schres.2015.06.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 06/18/2015] [Accepted: 06/28/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND We aimed to examine the association between lifetime cannabis use and estimates of both premorbid and current cognitive function in psychotic disorders in an Australian cohort. METHODS In an Australian multicenter cohort, 1237 participants with an established ICD-10 diagnosis of psychotic disorder were categorised according to history of lifetime cannabis use (non-users, n=354; cannabis users, n=221; cannabis dependency, n=662). Groups were analyzed according to available indices of cognitive ability: the National Adult Reading Test - Revised (NART-R) for ability prior to illness onset; and the Digit Symbol Coding Test (DSCT) for current ability. Two-way analysis of variance was conducted without any covariate, followed by a two-way analysis of covariance (using age, age at onset of psychiatric illness, premorbid IQ and the Socio-Economic Index for Areas (SEIFA) rankings). RESULTS Whilst there appeared to be a significant association between cannabis use and mean DSCT (higher DSCT scores in cannabis using groups) F(2,1080)=9.478, p<0.001, η2=0.017), once covariates were used in the analysis there were no significant differences between groups in mean DSCT scores (F(2,1011)=0.929, p=0.395, η2=0.002). Similarly there were no differences between groups in mean NART scores once, age, age at illness onset and SEIFA rankings were used as covariates (F(2,1032)=1.617, p=0.199, η2=0.003). CONCLUSIONS Confounding variables underpin the association between cannabis use and cognitive function in psychotic disorders. Taken together, it would appear that cannabis use or dependence has no additive effect on cognitive dysfunction in these disorders.
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Affiliation(s)
- Brian D Power
- School of Medicine Fremantle, The University of Notre Dame Australia, Fremantle, Australia; South Metropolitan Area Health Service, Perth, Australia; Clinical Research Centre, North Metropolitan Health Service - Mental Health, Perth, Australia.
| | - Milan Dragovic
- Clinical Research Centre, North Metropolitan Health Service - Mental Health, Perth, Australia; School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia
| | - Johanna C Badcock
- School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia; Centre for Clinical Research in Neuropsychiatry, School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia
| | - Vera A Morgan
- School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia; Centre for Clinical Research in Neuropsychiatry, School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia
| | - David Castle
- St. Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - Assen Jablensky
- School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia; Centre for Clinical Research in Neuropsychiatry, School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia
| | - Nikos C Stefanis
- Clinical Research Centre, North Metropolitan Health Service - Mental Health, Perth, Australia; School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Australia
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Lee J, Green MF, Calkins ME, Greenwood TA, Gur RE, Gur RC, Lazzeroni LC, Light GA, Nuechterlein KH, Radant AD, Seidman LJ, Siever LJ, Silverman JM, Sprock J, Stone WS, Sugar CA, Swerdlow NR, Tsuang DW, Tsuang MT, Turetsky BI, Braff DL. Verbal working memory in schizophrenia from the Consortium on the Genetics of Schizophrenia (COGS) study: the moderating role of smoking status and antipsychotic medications. Schizophr Res 2015; 163:24-31. [PMID: 25248939 PMCID: PMC4368500 DOI: 10.1016/j.schres.2014.08.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 08/03/2014] [Accepted: 08/06/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Working memory impairment has been extensively studied in schizophrenia, but less is known about moderators of the impairment. Using the Consortium on the Genetics of Schizophrenia case-control study (COGS-2), we examined smoking status, types of antipsychotic medication, and history of substance as moderators for working memory impairment in schizophrenia. METHODS From 5 sites, 1377 patients with schizophrenia or schizoaffective, depressed type and 1037 healthy controls completed the letter-number span (LNS) task. The LNS uses intermixed letter and digit stimuli that increase from 2 up to 8 stimuli. In the forward condition, participants repeated the letters and numbers in the order they were presented. In the reorder condition, participants repeated the digits in ascending order followed by letters in alphabetical order. RESULTS Schizophrenia patients performed more poorly than controls, with a larger difference on reorder than forward conditions. Deficits were associated with symptoms, functional capacity, and functional outcome. Patients who smoked showed larger impairment than nonsmoking patients, primarily due to deficits on the reorder condition. The impairing association of smoking was more pronounced among patients taking first-generation than those taking second-generation antipsychotic medications. Correlations between working memory and community functioning were stronger for nonsmokers. History of substance use did not moderate working memory impairment. CONCLUSIONS Results confirm the working memory impairment in schizophrenia, and indicate smoking status as an important moderator for these deficits. The greater impairment in smokers may reflect added burden of smoking on general health or that patients with greater deficits are more likely to smoke.
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Affiliation(s)
- Junghee Lee
- Department of Psychiatry and Biobehavioral Science, Geffen School of Medicine, University of California Los Angeles, CA, United States; VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States.
| | - Michael F. Green
- Department of Psychiatry and Biobehavioral Science, Geffen School of Medicine, University of California Los Angeles, CA, United States
,VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
| | - Monica E. Calkins
- Department of Psychiatry, University of Pennsylvania, Philadelphia, United States
| | - Tiffany A. Greenwood
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States
| | - Raquel E. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, United States
| | - Ruben C. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, United States
| | - Laura C. Lazzeroni
- Department of Psychiatry and Behavioral Science, Stanford University, Stanford, CA United States
,Department of Pediatrics, Stanford University, Stanford, CA, United States
| | - Gregory A. Light
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States
,VISN22, Mental Illness Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, United States
| | - Keith H. Nuechterlein
- Department of Psychiatry and Biobehavioral Science, Geffen School of Medicine, University of California Los Angeles, CA, United States
| | - Allen D. Radant
- Department of Psychiatry and Behavioral Science, University of Washington, Seattle, WA, United States
,VA Puget Sound Healthcare System, Seattle, WA, United States
| | - Larry J. Seidman
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States
,Massachusetts Mental Health Center Public Psychiatry Devision of the Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Larry J. Siever
- Department of Psychiatry, The Mount Sinai School of Medicine, New York, NY, United States
,James J. Peters VA Medical Center, New York, NY, United States
| | - Jeremy M. Silverman
- Department of Psychiatry, The Mount Sinai School of Medicine, New York, NY, United States
,James J. Peters VA Medical Center, New York, NY, United States
| | - Joyce Sprock
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States
,VISN22, Mental Illness Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, United States
| | - William S. Stone
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States
,Massachusetts Mental Health Center Public Psychiatry Devision of the Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Catherine A. Sugar
- Department of Psychiatry and Biobehavioral Science, Geffen School of Medicine, University of California Los Angeles, CA, United States
,VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
,Department of Biostatistics, University of California Los Angeles, CA, United States
| | - Neal R. Swerdlow
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States
| | - Debby W. Tsuang
- Department of Psychiatry and Behavioral Science, University of Washington, Seattle, WA, United States
,VA Puget Sound Healthcare System, Seattle, WA, United States
| | - Ming T. Tsuang
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States
,Institute for Genomic Medicine, University of California, San Diego, CA, United States
,Harvard Institute of Psychiatry Epidemiology and Genetics, Boston, MA, United States
| | - Bruce I. Turetsky
- Department of Psychiatry, University of Pennsylvania, Philadelphia, United States
| | - David L. Braff
- Department of Psychiatry, University of California San Diego, La Jolla, CA, United States
,VISN22, Mental Illness Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, United States
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Løberg EM, Helle S, Nygård M, Berle JØ, Kroken RA, Johnsen E. The Cannabis Pathway to Non-Affective Psychosis may Reflect Less Neurobiological Vulnerability. Front Psychiatry 2014; 5:159. [PMID: 25477825 PMCID: PMC4235385 DOI: 10.3389/fpsyt.2014.00159] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 10/24/2014] [Indexed: 12/19/2022] Open
Abstract
There is a high prevalence of cannabis use reported in non-affective psychosis. Early prospective longitudinal studies conclude that cannabis use is a risk factor for psychosis, and neurochemical studies on cannabis have suggested potential mechanisms for this effect. Recent advances in the field of neuroscience and genetics may have important implications for our understanding of this relationship. Importantly, we need to better understand the vulnerability × cannabis interaction to shed light on the mediators of cannabis as a risk factor for psychosis. Thus, the present study reviews recent literature on several variables relevant for understanding the relationship between cannabis and psychosis, including age of onset, cognition, brain functioning, family history, genetics, and neurological soft signs (NSS) in non-affective psychosis. Compared with non-using non-affective psychosis, the present review shows that there seem to be fewer stable cognitive deficits in patients with cannabis use and psychosis, in addition to fewer NSS and possibly more normalized brain functioning, indicating less neurobiological vulnerability for psychosis. There are, however, some familiar and genetic vulnerabilities present in the cannabis psychosis group, which may influence the cannabis pathway to psychosis by increasing sensitivity to cannabis. Furthermore, an earlier age of onset suggests a different pathway to psychosis in the cannabis-using patients. Two alternative vulnerability models are presented to integrate these seemingly paradoxical findings.
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Affiliation(s)
- Else-Marie Løberg
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Psychology, University of Bergen, Bergen, Norway
| | - Siri Helle
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Merethe Nygård
- Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
| | - Jan Øystein Berle
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Rune A. Kroken
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Erik Johnsen
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
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Bahorik AL, Cornelius JR, Bangalore SS, Newhill CE, Keshavan MS, Eack SM. BRIEF REPORT: THE IMPACT OF ALCOHOL AND CANNABIS MISUSE ON COGNITION AMONG INDIVIDUALS WITH SCHIZOPHRENIA. Schizophr Res Cogn 2014; 1:160-163. [PMID: 25419516 PMCID: PMC4235155 DOI: 10.1016/j.scog.2014.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Amber L. Bahorik
- School of Social Work, University of Pittsburgh, 2117 Cathedral of Learning, Pittsburgh, PA, United States, 15260
| | - Jack R. Cornelius
- Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811, O’Hara St, Pittsburgh PA, United States, 15213
| | - Srihari S. Bangalore
- Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811, O’Hara St, Pittsburgh PA, United States, 15213
| | - Christina E. Newhill
- School of Social Work, University of Pittsburgh, 2117 Cathedral of Learning, Pittsburgh, PA, United States, 15260
| | - Matcheri S. Keshavan
- Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811, O’Hara St, Pittsburgh PA, United States, 15213
- Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 02215
| | - Shaun M. Eack
- School of Social Work, University of Pittsburgh, 2117 Cathedral of Learning, Pittsburgh, PA, United States, 15260
- Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811, O’Hara St, Pittsburgh PA, United States, 15213
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Wongupparaj P, Kumari V, Morris RG. Executive function processes mediate the impact of working memory impairment on intelligence in schizophrenia. Eur Psychiatry 2014; 30:1-7. [PMID: 25169445 DOI: 10.1016/j.eurpsy.2014.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/03/2014] [Accepted: 06/04/2014] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE The study investigated working memory, executive functions (conceptualized as response inhibition, updating, and shifting), and intelligence in schizophrenia, using structural equation modelling to determine the relationship between working memory and intelligence, testing whether specific executive functions act as a mediator for the association. METHOD One hundred and twenty-five individuals diagnosed with schizophrenia and 64 healthy participants were included in the study, tested using measures of working memory, intelligence and executive functioning. Structural equation modelling (SEM) was used to estimate direct and indirect associations between main measures. RESULTS The schizophrenia group had significantly lower working memory, executive function and intelligence than the healthy group. The relationship between working memory and intelligence was significantly mediated by inhibition, updating and shifting functions. CONCLUSION The study indicates a mediating role of executive functions in determining the association between working memory and intellectual function in schizophrenia. It is further proposed that in people with schizophrenia, cognitive remediation approaches targeting working memory through executive functioning may in turn improve intellectual function generally.
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Affiliation(s)
- P Wongupparaj
- Department of Psychology, P078, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK.
| | - V Kumari
- Department of Psychology, P078, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK; NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation Trust, London, UK
| | - R G Morris
- Department of Psychology, P078, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK
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Wojtalik JA, Barch DM. An FMRI study of the influence of a history of substance abuse on working memory-related brain activation in schizophrenia. Front Psychiatry 2014; 5:1. [PMID: 24478729 PMCID: PMC3896871 DOI: 10.3389/fpsyt.2014.00001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 01/03/2014] [Indexed: 11/18/2022] Open
Abstract
There has been little investigation of the effects of past substance abuse (SA) on working memory (WM) impairments in schizophrenia. This study examined the behavioral and neurobiological impact of past SA (6 months or longer abstinence period) on WM in schizophrenia. Thirty-seven schizophrenia patients (17 with past SA and 20 without) and 32 controls (12 with past SA and 20 without) completed two versions of a two-back WM task during fMRI scanning on separate days. Analyses focused on regions whose patterns of activation replicated across both n-back tasks. Schizophrenia patients were significantly less accurate than controls on both n-back tasks. No main effects or interactions with past SA on WM performance were observed. However, several fronto-parietal-thalamic regions showed an interaction between diagnostic group and past SA. These regions were significantly more active in controls with past SA compared to controls without past SA. Schizophrenia patients with or without past SA either showed no significant differences, or patients with past SA showed somewhat less activation compared to patients without past SA during WM. These results suggest robust effects of past SA on WM brain functioning in controls, but less impact of past SA in schizophrenia. This is consistent with previous literature indicating less impaired neurocognition in schizophrenia with SA.
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Affiliation(s)
- Jessica A Wojtalik
- Department of Psychiatry, Washington University School of Medicine , St. Louis, MO , USA
| | - Deanna M Barch
- Department of Psychiatry, Washington University School of Medicine , St. Louis, MO , USA ; Department of Psychology, Washington University in St. Louis , St. Louis, MO , USA ; Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine , St. Louis, MO , USA
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9
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Thoma P, Daum I. Comorbid substance use disorder in schizophrenia: a selective overview of neurobiological and cognitive underpinnings. Psychiatry Clin Neurosci 2013; 67:367-83. [PMID: 23890122 DOI: 10.1111/pcn.12072] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/21/2013] [Accepted: 05/29/2013] [Indexed: 01/06/2023]
Abstract
Although individuals with schizophrenia show a lifetime prevalence of 50% for suffering from a comorbid substance use disorder, substance abuse usually represents an exclusion criterion for studies on schizophrenia. This implies that surprisingly little is known about a large group of patients who are particularly difficult to treat. The aim of the present work is to provide a brief and non-exhaustive overview of the current knowledgebase about neurobiological and cognitive underpinnings for dual diagnosis schizophrenia patients. Studies published within the last 20 years were considered using computerized search engines. The focus was on nicotine, caffeine, alcohol, cannabis and cocaine being among the most common substances of abuse. All drugs of abuse target dopaminergic, glutamatergic and GABAergic transmission which are also involved in the pathophysiology of schizophrenia. Current literature suggests that neurocognitive function might beless disrupted in substance-abusing compared to non-abusing schizophrenia patients, but in particular the neuroimaging database on this topic is sparse. Detrimental effects on brain structure and function were shown for patients for whom alcohol is the main substance of abuse. It is as yet unclear whether this finding might be an artifact of age differences of patient subgroups with different substance abuse patterns. More research is warranted on the specific neurocognitive underpinnings of schizophrenia patients abusing distinct psychoactive substances. Treatment programs might either benefit from preserved cognitive function as a resource or specifically target cognitive impairment in different subgroups of addicted schizophrenia patients.
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Affiliation(s)
- Patrizia Thoma
- Department of Neuropsychology, Institute of Cognitive Neuroscience, Ruhr-University Bochum, Bochum, Germany.
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10
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Benaiges I, Serra-Grabulosa JM, Adan A. Neuropsychological functioning and age-related changes in schizophrenia and/or cocaine dependence. Prog Neuropsychopharmacol Biol Psychiatry 2013; 40:298-305. [PMID: 23123363 DOI: 10.1016/j.pnpbp.2012.10.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 10/09/2012] [Accepted: 10/23/2012] [Indexed: 02/07/2023]
Abstract
Although little is known about the combined effects of Schizophrenia (SZ) and Substance Use Dependence (SUD) in neurocognitive functioning, the current literature points out that performance depends on the specific cognitive domains, the age of individuals and the type of substance of abuse. Our aim is to elucidate, in a sample with SZ and/or cocaine dependent individuals in remission for more than 4 months, their performance in attention, verbal memory and speed of processing, taking into account the possible effect of both age and duration of SUD. The total sample consisted of 95 male patients, aged 20 to 60 years, divided in three groups: one group with SZ and cocaine dependence (SZ+), another group with SZ without cocaine dependence (SZ-) and a third group with cocaine dependence without psychiatric comorbidity (COC). Our results show that those SZ+ who were abstinent for more than four months did not differ from their SZ- counterparts in the neuropsychological functioning. Both SZ groups performed significantly worse than the COC group. A negative impact of age on the neuropsychological performance was found in the SZ+ group, suggesting additive later cognitive deficits in SZ+ patients due to the long-term brain damage of SUD.
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Affiliation(s)
- Irina Benaiges
- Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Spain.
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11
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Benaiges I, Serra-Grabulosa JM, Prat G, Adan A. Executive functioning in individuals with schizophrenia and/or cocaine dependence. Hum Psychopharmacol 2013; 28:29-39. [PMID: 23166052 DOI: 10.1002/hup.2279] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/28/2012] [Accepted: 10/17/2012] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Although little is known about neurocognition in Dual Diagnosis, it has been suggested that Schizophrenia (SZ) patients with comorbid substance use belong to a subgroup with lower genetic vulnerability to develop SZ and, consequently, they show better executive and social premorbid functioning. The first aim of this study was to assess the executive functioning, and the second one was to explore the effect of age of onset of substance use in neurocognition in SZ patients with cocaine dependence. METHODS The total sample consisted of 95 male patients, aged 20 to 60 years, divided in three groups: one group with SZ and cocaine dependence (SZ+; n = 30), another group with SZ without cocaine dependence (SZ-; n = 30), and a control group with cocaine dependence without psychiatric comorbidity (COC; n = 35). RESULTS We found a better executive functioning in both SZ+ and COC than SZ-. We observed a worse performance of SZ+ patients compared with COC in cognitive set-shifting regardless the age of onset of consumption. CONCLUSIONS The results agree with the hypothesis of a lower genetic vulnerability in SZ+ patients to develop psychosis compared with SZ-, who develop it without any additional trigger. However, future research is needed to clarify the current knowledge gaps.
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Affiliation(s)
- Irina Benaiges
- Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain
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Scherzer P, Leveillé E, Achim A, Boisseau E, Stip E. A study of theory of mind in paranoid schizophrenia: a theory or many theories? Front Psychol 2012; 3:432. [PMID: 23162496 PMCID: PMC3497936 DOI: 10.3389/fpsyg.2012.00432] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/01/2012] [Indexed: 11/30/2022] Open
Abstract
Social cognitive psychologists (Frith, 1992; Hardy-Baylé et al., 2003) sought to explain the social problems and clarify the clinical picture of schizophrenia by proposing a model that relates many of the symptoms to a problem of metarepresentation, i.e., theory of mind (ToM). Given the differences in clinical samples and results between studies, and considering the wide range of what is considered to constitute ToM, one must ask if there a core function, or is ToM multifaceted with dissociable facets? If, there are dissociable dimensions or facets, which are affected in patients with paranoid schizophrenia? To answer these questions, a group of 21 individuals diagnosed with paranoid schizophrenia and 29 non-clinical control subjects, were tested on a battery of five different measures of ToM. The results confirmed that there was little difference in specificity of three of the tests in distinguishing between the clinical and non-clinical group, but there were important differences in the shared variance between the tests. Further analyses hint at two dimensions although a single factor with the same variance and the same contributing weights in both groups could explain the results. The deficits related to the attribution of cognitive and affective states to others inferred from available verbal and non-verbal information. Further analyses revealed that incorrect attributions of mental states including the attribution of threatening intentions to others, non-interpretative responses and incomplete answers, depending on the test of ToM.
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Affiliation(s)
- Peter Scherzer
- Département de Psychologie, Université du Québec à MontréalMontréal, QC, Canada
- Institut des Sciences Cognitives, Université du Québec à MontréalMontréal, QC, Canada
| | - Edith Leveillé
- Département de Psychologie, Université du Québec à MontréalMontréal, QC, Canada
| | - André Achim
- Département de Psychologie, Université du Québec à MontréalMontréal, QC, Canada
- Institut des Sciences Cognitives, Université du Québec à MontréalMontréal, QC, Canada
| | | | - Emmanuel Stip
- Centre de Recherche Fernand Séguin de l’Hôpital Louis H. LafontaineMontréal, QC, Canada
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Thoma P, Hennecke M, Mandok T, Wähner A, Brüne M, Juckel G, Daum I. Proverb comprehension impairments in schizophrenia are related to executive dysfunction. Psychiatry Res 2009; 170:132-9. [PMID: 19906437 DOI: 10.1016/j.psychres.2009.01.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 01/13/2009] [Accepted: 01/21/2009] [Indexed: 10/20/2022]
Abstract
The study aimed to investigate the pattern of proverb comprehension impairment and its relationship to proverb familiarity and executive dysfunction in schizophrenia. To assess the specificity of the impairment pattern to schizophrenia, alcohol-dependent patients were included as a psychiatric comparison group, as deficits of executive function and theory of mind as well as dysfunction of the prefrontal cortex, which have been related to proverb comprehension difficulties, are common in both disorders. Twenty-four schizophrenia patients, 20 alcohol-dependent patients and 34 healthy controls were administered a multiple-choice proverb interpretation task incorporating ratings of subjective familiarity and measures of executive function. Schizophrenia patients chose the correct abstract and meaningful interpretations less frequently and instead chose the incorrect concrete (both meaningless and meaningful) proverb interpretations more often than alcohol-dependent patients and healthy controls. Relative to healthy controls, schizophrenia patients also chose more abstract-meaningless response alternatives and were impaired in all executive domains. Impaired divided attention was most consistently associated with proverb interpretation deficits in both patient groups. Taken together, schizophrenia patients showed a specific pattern of proverb comprehension impairments related to executive dysfunction and symptoms. The comparison with the alcohol-dependent subgroup suggests that a more comprehensive and severe impairment of complex higher-order cognitive functions including executive behavioural control and non-literal language comprehension might be associated with frontal dysfunction in schizophrenia as compared to alcohol use disorder.
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Affiliation(s)
- Patrizia Thoma
- Dept. of Neuropsychology, Ruhr-University of Bochum, 44780 Bochum, Germany.
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Løberg EM, Hugdahl K. Cannabis use and cognition in schizophrenia. Front Hum Neurosci 2009; 3:53. [PMID: 19956405 PMCID: PMC2786315 DOI: 10.3389/neuro.09.053.2009] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 11/04/2009] [Indexed: 12/02/2022] Open
Abstract
People with schizophrenia frequently report cannabis use, and cannabis may be a risk factor for schizophrenia, mediated through effects on brain function and biochemistry. Thus, it is conceivable that cannabis may also influence cognitive functioning in this patient group. We report data from our own laboratory on the use of cannabis by schizophrenia patients, and review the existing literature on the effects of cannabis on cognition in schizophrenia and related psychosis. Of the 23 studies that were found, 14 reported that the cannabis users had better cognitive performance than the schizophrenia non-users. Eight studies reported no or minimal differences in cognitive performance in the two groups, but only one study reported better cognitive performance in the schizophrenia non-user group. Our own results confirm the overall impression from the literature review of better cognitive performance in the cannabis user group. These paradoxical findings may have several explanations, which are discussed. We suggest that cannabis causes a transient cognitive breakdown enabling the development of psychosis, imitating the typical cognitive vulnerability seen in schizophrenia. This is further supported by an earlier age of onset and fewer neurological soft signs in the cannabis-related schizophrenia group, suggesting an alternative pathway to psychosis.
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Affiliation(s)
- Else-Marie Løberg
- Department of Biological and Medical Psychology, University of Bergen Bergen, Norway.
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