Decision making in euthymic bipolar disorders: Their relationship with suicidal behaviour

MARTINO D.J., STREJILEVICH S.A., TORRALVA T., MANES F.

Amsterdam, Holanda

Congreso; 23rd European College of Neuropsychopharmacology Congress; 2010

Background: Neurocognitive impairments have been identified as a core feature of bipolar disorder (BD). [1]. Among cognitive functions, decision making is particularly important in BD since it is included in clinical descriptions of both depressive and manic episodes (DSM-IV). Results of previous studies are controversial regarding to decision making abilities in euthymic patients [2,3]. Additionally, preliminary evidence showed an association between impairments in decision making and vulnerability to suicidal behaviour [3]. The aim of this study was to compare a large population of bipolar I and II (BD) patients strictly defined as euthymic, and healthy controls, on measures of decision-making. An additional aim was to compare performance on a decision-making task between patients with and without past history of suicide attempt. Methods: Eighty-five euthymic patients with BDI or BDII and 34 healthy controls were included. All subjects completed tests to assess verbal memory, attention, and executive functions, as well as a decision making paradigm (the Iowa Gambling Task, IGT). The three groups (BDI, BDII, and healthy controls) were compared in clinical-demographical variables using analysis of variance (ANOVA) and chi squared tests as appropriate. A Tukey post hoc comparison procedure was used followed ANOVA when significant main effects were present. In addition, we repeated these analyses to compare patients with and without history of suicide attempts. Results: No differences between groups were found on clinical-demographical variables sucha as age, gender, education, premorbid IQ, and scores in Young Mania Rating Scale and Hamilton Depression Rating Scale (all p >0.05). Both groups of patients had lower performance than healthy controls on measures of verbal memory, attention, and executive function (table 1). No significant differences were found between BD I, BD II, and healthy controls on measures of decision making (table 1). Twenty six percent of the patients sample had at least 1 suicide attempt. When we compared BD patients with and without suicide attempts, no differences were found in terms of verbal memory, attention, and executive functions measures (all p >0.05). Suicide attempt patients selected more cards from deck A [17.7 (8.2) vs. 14.3 (5.8), F=4.20, df=1, P=0.044] and lower cards from deck C [19.9 (10.8) vs. 26.2 (12.3), F=4.25, df=1, P=0.042] than non-suicide attempt patients in the IGT. Conclusions: Patients BDI and BDII with strict euthymia criteria had not impairments in a decision making paradigm, suggesting that this does not represent a reliable trait-marker of the disorder. Additionally, our results provide further evidence of an association between impairments in decision-making and vulnerability to suicidal behavior. A decreased serotonergic function has been related with both impairments in decision making and suicidal behavior. Future researches assessing measures of serotonergic function combined with functional neuroimaging techniques and a decision making paradigm would be useful to enlighten this relationship.