Comparison of executive functions in different phases of bipolar i disorder in patients and general population

Abstract

Background: Bipolar I disorder (BID) is a complex and chronic disorder characterized by episodes of mania and depression. Considering the possibility of neuropsychological function deficit in patients with bipolar disorder, the purpose of this study was to determine the mean scores of executive functions (cognitive flexibility and working memory) in mania, euthymia, and depression in bipolar I disorder and compare them with controls. Methods: In a causal-comparative study in 2016, 41 patients with bipolar I disorder referring to emergency rooms, psychiatric departments, and clinics of Isfahan University of Medical Sciences, Iran, with psychiatrist’s diagnosis based on Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5), Young Mania Scale, and Hamilton Depression Scale, and 18 healthy controls based on Symptom Checklist-90-Revised V.4.1 (SCl-90-R V.4.1) and Short Form Health Survey-36 (SF-36) questionnaires were selected to participate in the study through convenience sampling. The participants were compared using Computerized Wisconsin Card Sorting Test-Version 3 (WCST-V3) and Working Memory WIS Software V-4 (WMW V-4). Findings: In indices of executive functions, there were no significant differences among patients, but compared to the controls, in the Wisconsin test, patients had less number of correct categories (P = 0.004), more perseveration error (P < 0.0001), more attempts (P = 0.001), more false responses (P = 0.003), and longer test implementation time (P = 0.002). Performance of the mania group in all indices of working memory was significantly lower than controls (P < 0.05o for all). Euthymic patients had a weaker performance in comparison to controls in visual forward digit-span (P < 0.001), and total visual memory (P < 0.0001). Conclusion: Bipolar disorder is associated with cognitive deficits, and executive function deficit is more evident in the mania phase. These deficits are found even during the euthymic phase. Considering controversial findings, further studies seem to be necessary. © 2018, Isfahan University of Medical Sciences(IUMS). All rights reserved.