Sean P Carruthers1, Caroline T Gurvich2, Denny Meyer1,3, Chad Bousman4,5,6, Ian P Everall4,6,7,8,9, Erica Neill1,6,7, Christos Pantelis4,6,7,9,10, Philip J Sumner1, Eric J Tan1,11, Elizabeth H X Thomas2, Tamsyn E Van Rheenen1,10, Susan L Rossell1,11. 1. Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University of Technology, Victoria 3122, Australia. 2. Monash Alfred Psychiatry Research Centre (MAPrc), Monash University Central Clinical School and The Alfred Hospital, Melbourne 3004, Australia. 3. Department of Statistics, Data Science and Epidemiology, Swinburne University of Technology, Victoria 3122, Australia. 4. Cooperative Research Centre (CRC) for Mental Health, 161 Barry Street, Carlton, Victoria 3053, Australia. 5. Departments of Medical Genetics, Psychiatry, and Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada. 6. Department of Psychiatry, The University of Melbourne, Parkville, Victoria 3052, Australia. 7. Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia. 8. Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK. 9. Centre for Neural Engineering, The University of Melbourne, Carlton, VIC, Australia. 10. Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, Victoria 3053, Australia. 11. Department of Mental Health, St Vincent's Hospital, Melbourne, Victoria 3065, Australia.
Abstract
OBJECTIVES: The Wisconsin Card Sorting Test (WCST) is a complex measure of executive function that is frequently employed to investigate the schizophrenia spectrum. The successful completion of the task requires the interaction of multiple intact executive processes, including attention, inhibition, cognitive flexibility, and concept formation. Considerable cognitive heterogeneity exists among the schizophrenia spectrum population, with substantive evidence to support the existence of distinct cognitive phenotypes. The within-group performance heterogeneity of individuals with schizophrenia spectrum disorder (SSD) on the WCST has yet to be investigated. A data-driven cluster analysis was performed to characterise WCST performance heterogeneity. METHODS: Hierarchical cluster analysis with k-means optimisation was employed to identify homogenous subgroups in a sample of 210 schizophrenia spectrum participants. Emergent clusters were then compared to each other and a group of 194 healthy controls (HC) on WCST performance and demographic/clinical variables. RESULTS: Three clusters emerged and were validated via altered design iterations. Clusters were deemed to reflect a relatively intact patient subgroup, a moderately impaired patient subgroup, and a severely impaired patient subgroup. CONCLUSIONS: Considerable within-group heterogeneity exists on the WCST. Identification of subgroups of patients who exhibit homogenous performance on measures of executive functioning may assist in optimising cognitive interventions. Previous associations found using the WCST among schizophrenia spectrum participants should be reappraised. (JINS, 2019, 25, 750-760).
OBJECTIVES: The Wisconsin Card Sorting Test (WCST) is a complex measure of executive function that is frequently employed to investigate the schizophrenia spectrum. The successful completion of the task requires the interaction of multiple intact executive processes, including attention, inhibition, cognitive flexibility, and concept formation. Considerable cognitive heterogeneity exists among the schizophrenia spectrum population, with substantive evidence to support the existence of distinct cognitive phenotypes. The within-group performance heterogeneity of individuals with schizophrenia spectrum disorder (SSD) on the WCST has yet to be investigated. A data-driven cluster analysis was performed to characterise WCST performance heterogeneity. METHODS: Hierarchical cluster analysis with k-means optimisation was employed to identify homogenous subgroups in a sample of 210 schizophrenia spectrum participants. Emergent clusters were then compared to each other and a group of 194 healthy controls (HC) on WCST performance and demographic/clinical variables. RESULTS: Three clusters emerged and were validated via altered design iterations. Clusters were deemed to reflect a relatively intact patientsubgroup, a moderately impaired patient subgroup, and a severely impaired patient subgroup. CONCLUSIONS: Considerable within-group heterogeneity exists on the WCST. Identification of subgroups of patients who exhibit homogenous performance on measures of executive functioning may assist in optimising cognitive interventions. Previous associations found using the WCST among schizophrenia spectrum participants should be reappraised. (JINS, 2019, 25, 750-760).
Entities:
Keywords:
Cognitive flexibility; Cognitive subgroup; Concept formation; Executive function; Psychosis; Schizophrenia spectrum and other psychotic disorders