Schizotypal Traits and Neuropsychological Performance: The Role of Processing Speed

James Gilleen, Marcello Tesse, Tjasa Velikonja, Mark Weiser, Michael Davidson, Abraham Reichenberg

Research output: Contribution to journalArticlepeer-review

Abstract

Background: Cognitive deficits, particularly in processing speed, are widely recognized as a critical feature of schizophrenia, and are also present across schizophrenia spectrum disorders. A number of important confounders, however, such as hospitalization effects and antipsychotic medication, have been shown to affect processing speed, causing debate as to the core cognitive deficits of schizophrenia. The study of individuals who are not clinically psychotic but have schizotypal traits allows investigation of cognitive deficits associated with both positive and negative schizotypy dimensions while excluding potential confounds. Methods: A population-based community sample of 242 healthy adult volunteers assessed using the Structured Interview of Schizotypy – Revised (SIS-R) scale, and a neuropsychological testing battery that included measures of verbal ability, visual and verbal memory, verbal fluency, working memory, executive functions and processing speed. Participants were classified in High or Low Positive Schizotypy (H-PST or L-PST), High or Low Paranoia-like traits (H-PAR or L-PAR) and High or Low Negative Schizotypy (H-NST or L-NST) groups, respectively. Results: Individuals with H-PST performed significantly (p<0.05) worse than L-PST on measures of processing speed and executive functions. Processing speed deficits were also observed in individuals with H-PAR compared to L-PAR (p<0.05). There were no statistically significant differences in neuropsychological performance between H-NST and L-NST on any measure.Conclusions: In a population-based community sample, individuals with high positive schizotypal traits or paranoia-like traits show impairments in processing speed. Consistent with a dimensional view of psychosis, this supports the hypothesis that processing speed represents a core deficit of schizophrenia-like mental states.

© 2020, Elsevier B.V. All rights reserved. The attached document (embargoed until 04/07/2021) is an author produced version of a paper published in SCHIZOPHRENIA RESEARCH uploaded in accordance with the publisher’s self-archiving policy. The final published version (version of record) is available online at the link. Some minor differences between this version and the final published version may remain. We suggest you refer to the final published version should you wish to cite from it.

Original languageEnglish
JournalSCHIZOPHRENIA RESEARCH
Early online date4 Jul 2020
DOIs
Publication statusPublished - 4 Jul 2020

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