Most of the studies have indicated that there have been neurocognitive impairments especially in the domains of executive functions, attention, verbal and working memory among euthymic patients with bipolar disorder type I (BD-I). However, there has been limited research investigating neurocognitive functioning in euthymic patients with BD- II.

Aim of this study was to investigate neurocognitive functions in euthymic BD-II patients. Our hypothesis was that euthymic BD-II patients would have neurocognitive impairments in the domains of executive functions, attention, verbal and working memory.

Euthymic BD-II patients (n = 37) and healthy controls (HC) (n = 35) were compared in terms of their neurocognitive functioning in the domains of executive functions assesed by the number of perseverative errors, non-perseverative errors and category completed on the Wisconsin Cart Sorting Test (WCST); working memory assessed by Auditory Consonant Trigrams (ACT); immediate verbal memory assessed by the Logical Memory subscale of the Wechsler Memory Scale I (WMS I) and attention assesed by Stroop Colour-Word Interference Test (SCWIT). Euthymic state was confirmed by the low scores both on Hamilton Depression Rating Scale, Young Mania Rating Scale.

Significant differences were found between two groups in terms of WCST non-perseverative errors (Z = 3.8, P < 0.01) and category completed subtests (Z = 3.8, P < 0.01), ACT (t = 2.97, P < 0.01) WMSI (Z = 2.4, P = 0.01), SCWIT (t = 3.52, P < 0.01) performances.

Our study indicated that euthymic BD-II patients had poorer performance on the domains of executive functions, attention, working memory and verbal memory than the HC group. But future studies with large samples are needed to support our results.

The authors have not supplied their declaration of competing interest.