Cognitive abilities and clinical variables in bipolar I depressed and euthymic patients and controls.
BACKGROUND
While studies demonstrated that bipolar patients (BP) display cognitive deficits during mood episodes and remission, little is known about the clinical influences underlying these deficits. The aim of this study was to compare the performance of euthymic and depressed BPs and non-affective/psychotic disorder controls at several cognitive tasks, exploring which clinical variables influenced the performance of these subtests. It is hypothesized that the cognitive deficits in rank order are: depressed BPs > euthymic BPs > controls.


METHODS
Sixty-five bipolar-I outpatients and thirty-four controls were assessed by the Brazilian version of the Wechsler Adult Intelligence Scale, Third Edition (WAIS-III). BPs were divided into depressed and euthymics, and these two groups were then compared to non-affective/psychotic disorder controls.


RESULTS
For 12 of 14 subtest scores, comparisons yielded statistically significant (p < 0.05) between-group differences, including three subtests of attention and working memory (Digit Span and its two subtests) with both depressed and euthymic BPs, compared to controls, displaying significantly worse performance, and six subtests of visual and working memory with depressed (but not euthymic) BPs performing worse than controls. For all subtests, comparisons of depressed and euthymic patients' scores were non-significant. Performance on several subtests was negatively predicted by the severity of the disorder in both patient groups.


CONCLUSIONS
The cross-sectional design of the study, as well as confounding effects of medications and co-morbidities.


CONCLUSIONS
The fact that the impairment of cognitive performance of both groups of patients is influenced by the severity of the illness is consistent with the literature.
Institute of Psychology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. yates_br@yahoo.com.br
Denise Balem
DB
Yates
Sandra
S
Dittmann
Flávio
F
Kapczinski
Clarissa Marceli
CM
Trentini
D000328:Adult; D001714:Bipolar Disorder / Q000150:complications* / Q000523:psychology*; D001938:Brazil / Q000453:epidemiology; D003072:Cognition Disorders / Q000209:etiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis