Psychiatry Research EG

Bipolar disorder has been identified by the WHO as the sixth cause of disability among all medical illnesses [1]. Until recently, it had been widely accepted that inbetween episodes of mania and depression, patients with bipolar disorder recovered completely and that euthymia was in essence normality [2]. However, recent studies have cast serious doubt on this assumption and have shown that euthymic bipolar patients continue to have psychosocial difficulties and have reduced ability to regain premorbid levels of social and vocational functioning even after episodes of remission, suggesting that a gap exists between syndromal recovery and functional recovery; this gap might be because of cognitive impairments [3]. Some of the evidence suggests that recurring episodes of bipolar disorder are associated with greater cognitive disturbance. It has been proposed that successive episodes cause subtle damage to brain areas, leading to the neurological and cognitive impairment observed in patients with bipolar disorder. However, the evidence linking cognitive deficits with indicators of severity and progression of illness is not always consistent [4]. Furthermore, cognitive deficits, most notably in attention, verbal learning, and executive function, can be observed across multiple phases of bipolar disorder, with deficits during acute episodes that are comparable in severity to those reported in schizophrenia [5–7]. More recent research suggests that the presence of cognitive dysfunction in bipolar disorder is a core and enduring deficit of the illness. The deficit is best characterized as impairment in attention and executive control of action, and represents an important marker for future neurobiological and pharmacological research [8]. The episodic nature of bipolar disorder requires that studies account for current mood symptoms, and clinical course factors, including the number of previous episodes, age at onset, and duration of illness, exert a direct effect on cognitive functioning [6]. These cognitive impairments are associated with poorer long-term psychosocial functional outcome. Wingo et al. [9] found that neurocognitive impairment was significantly associated with impaired psychosocial functioning, even after adjusting for residual mood symptoms and relevant demographic and clinical variables; B55% of patients with bipolar disorder were unemployed [10]. The issue of persistent cognitive deficits in euthymia is very important because of its potential as a trait marker for bipolar disorder. Low-functioning patients are found have greater cognitive impairment in verbal recall and executive functions and the variable that best predicts psychosocial functioning in euthymic bipolar patients is verbal memory [11]. This indicates that cognitive rehabilitation may be an important factor for restoring quality of life to baseline levels among patients with bipolar disorder.