Bipolar disorder is a common and disabling condition; its lifetime prevalence in general population is estimated by several studies to 1-5%.

There are data that prove the fact that patients with bipolar disorder show cognitive deficits in all stages of the disorder, but also during remission phases.

within bipolar disorder, bipolar depression occurs more frequently, lasts longer and has a higher rate of relapses than mania.

Bipolar patients usually complain of cognitive deficits such as attentional or memory deficits Patients with bipolar disorder experiment during depressive episodes dysfunctions in attention (difficulties in focusing and maintaining attention), memory (deficits of declarative and nondeclarative memory, affected verbal recall and recognition), language (bradyphemia with longer moments of pause during speech), psychomotor performance (psychomotor inhibition, slowness of motor functions when the number of tasks increases), executive functions (limited ability to acquire or relearn different skills), general intellectual functioning (information processing deficits).

Recent studies have made some suggestion regarding a certain degree of cognitive impairment that is also found in euthymic patients with bipolar disorder. in order to have a more accurate assessment regarding the degree of cognitive dysfunctions both during depressive episodes and euthymic phases in bipolar disorder, diagnosis criteria for depression and for remission should be strictly respected and coexisting factors that may influence the results should not be taken in consideration.