title: [Neurocognitive function in clinically stable patients with schizophrenia or bipolar disorder and normal controls].
abstract: There is a substantial body of evidence suggesting that cognitive deficits in schizophrenia (SΖ) and bipolar disorder (BD) persist after the subsidence of active symptoms. However, it is unclear whether the cognitive deficits observed in patients with BD are quantitatively or qualitatively similar to those in SΖ patients. The aim of the study was to assess and compare the cognitive functioning of patients with clinically stable SZ and BD. To the best of our knowledge, this is the first study including a comparison of the Theory of Mind between patients with SZ and BD. General intelligence, attention, speed of processing, working memory, verbal memory and learning, visuospatial ability, executive functions and ToM were assessed in 21 patients with SZ in remission, 23 euthymic BD type I patients, and 27 healthy controls (HC), using WAIS-Vocabulary, Block design, and Digit span, Babcock Story Recall Test, Rey Auditory Verbal Learning Test, Stroop Word-Colour Test, Wisconsin Card Sorting Test, Trail Making Test, and Faux Pas Recognition Test. The three groups were matched for gender, age and education. The SZ and BD groups were also matched in terms of illness duration and the age of the onset of the illness. To be enrolled in the study patients should have been clinically stable for 3 months, operationalized as no change in total Brief Psychiatric Rating Scale, Hamilton Depression Rating Scale (<8), and Young Mania Rating Scale (<6). One-way ANOVA with post hoc Bonferroni corrections was used for the between groups comparisons. Both BD and SC patients were significantly impaired in general intellectual ability, verbal memory and learning, and executive functions compared to HC. Patients with SZ performed significantly worse than patients with BD on verbal memory tasks, whereas BD group did not have significant lower score than SZ in any task. SZ patients performed worse than HC group on attention, processing speed and immediate memory tests, while BD patients on visuospatial ability and working memory. Both SZ and BD groups did not differ from HC regarding Theory of Mind. Our results indicate that stable SZ and euthymic BD exhibit similar profiles of cognitive impairment, consistently with previous studies suggesting that the differences are related to the extent and degree of impairments, rather than being qualitative. Finally, our findings offer support to the hypothesis that the Theory of Mind does not represent a trait marker of schizophrenia or bipolar disorder.
authors.affiliation: 1st Department of Psychiatry, Athens University Medical School, Athens, Greece. gekonst@otenet.gr
authors.forename: G
authors.initials: G
authors.lastname: Konstantakopoulos
authors.forename: N
authors.initials: N
authors.lastname: Ioannidi
authors.forename: P
authors.initials: P
authors.lastname: Patrikelis
authors.forename: A
authors.initials: A
authors.lastname: Soumani
authors.forename: P
authors.initials: P
authors.lastname: Oulis
authors.forename: D
authors.initials: D
authors.lastname: Sakkas
authors.forename: G N
authors.initials: GN
authors.lastname: Papadimitriou
authors.forename: D
authors.initials: D
authors.lastname: Ploumpidis
mesh_terms: D001714:Bipolar Disorder / Q000175:diagnosis* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D056344:Executive Function; D006801:Humans; D007360:Intelligence; D011939:Mental Recall; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D056345:Theory of Mind; D014706:Verbal Learning