Cognitive executive performance influences functional outcome in euthymic type I bipolar disorder outpatients

Background: There is a debate about the influence of executive functioning impairment in the functionality of Bipolar Disorder Type I, even when euthymic (EutBDI). The aim of this study was to explore this relationship, taking functional outcome from a multidimensional point of view. Methods: An extended neuropsychological battery of executive tests and measures of social functioning were administered to 31 EutBDI and 25 non-psychiatric patients. Percentage of patients scoring lower than -1.64 SD was calculated for each executive measure. This was compared in terms of clinical features to those with normal performance. Partial correlations and ANCOVA were applied between psychosocial and executive variables within the EutBDI-group. Results: Patients reached poorer scores in mental flexibility, plan implementing, set-shifting, and fluency (p<0.05). 76% of patients performed poorly on some of the executive tests, although only around 1/3 reached a clinical deficit (<-1.64SD). Executive functioning was related to some clinical, evolution, and treatment variables. A better use of leisure time, higher competence for independent living and holding a skilled type of profession were significantly associated with a better performance on planning, set-shifting, and fluency tasks. Conclusions: Persistent executive deficits in EutBDI may be related to their frequently reported difficulties in personaland occupational adjustment.