Cognitive deficits impair patients working and functioning status and may have negative impact on other aspects of thinking.

Assess the prevalence of cognitive dysfunction in patients with bipolar disorder in euthymic state and to explore cognitive style problems.

Case-control naturalistic study, 60 patients with bipolar I disorder in euthymic state according to DSM-IV were recruited and subdivided into two groups each contains of 30 patients; (Group BPM) euthymic patients with recent manic episode, Group BPD euthymic patients with recent depressive episode. Both groups were further compared with control group (Group C) consisted of 30 frequency matched healthy volunteers. Groups were subjected to the following: (1) clinical psychiatric examination, (2) (HAMD-17) and Bech–Rafaelsen Melancholia Scale (MES) for (BPD), (3) (YMRS) and Bech–Rafaelsen Mania Scale (MAS) for (BPM), (4) assessment of euthymic state of mood included both MAS and MES, (5) MMSE, MTS and CDT were performed to assess cognitive functions, (6) cognitive styles evaluation the Social Dysfunction and Aggression Scale SDAS-9 and Arabic Anger Scale.

Definite cognitive function impairment and different patterns of cognitive style were detected in case groups. MMSE, MTS and CDT scores were statistically significant. Fear of Failure Scale Scores were higher in BPM; 16 (53.33%) reported severe intensity compared to 16 (53.33%) of BPD Group reporting moderate intensity and 30 (100%) of the control group reporting only mild intensity of fear of failure with statistically significant differences.

Patients in euthymic state suffer from cognitive dysfunction and some aspects of cognitive styles that negatively interfere with their performance.

The authors have not supplied their declaration of competing interest.