A disorder in executive functions crosses traditional diagnostic borders of the schizophrenia-bipolar spectrum

Abstract

Introduction Our series of studies in the spectrum of psychosis (schizophrenia, bipolar affective disorder, schizoaffective disorder) is based on the concept of the RDoC system. Objectives In this study, we were interested in knowing whether cross-diagnostic disturbances in cognitive functions can be found in the spectrum and whether they predict clinical symptoms. Methods In the study, N = 66 schizophrenic (M = 38.2 ± 9.37 years, 26 women), N = 30 bipolar (M = 47.4 ± 9.35 years, 19 women), N = 33 schizoaffective (M = 39.8 years± 11.3 years, 21 women) and N = 28 healthy subjects (M = 36.5 ± 9.9 years, 14 women) participated. All subjects underwent the Wisconsin Card Sorting Test (WCST), Raven Test, Digit Span Test, Visual Patterns Test, Letter and Semantic Fluency tests, Metaphor and Irony Comprehension, Directed Forgetting, Stop Signal Test, and Lexical Decision Task. In addition, symptom rating scales were administered (PANSS, SANS, YMRS, MADRS). Results Based on our results, the performance of the WCST-deficient group lagged behind the WCST-non-deficient group and the healthy control group in most executive control tests. Importantly, this effect was independent of diagnosis, so it appeared in all three patient groups. Members of the deficit group had a higher rate of negative symptoms. Conclusions Disruption of executive functions is a transdiagnostic feature of the schizophrenia-bipolar spectrum, which could be associated with any diagnosis. Disclosure No significant relationships.

Keywords

• Transdiagnostic
• RDoC
• Executive functions
• WCST