Functional impairment and cognition in bipolar disorder.

Bipolar disorder is a common, chronic and severe mental disorder, affecting approximately 2% of the adult population. Bipolar disorder causes substantial psychosocial morbidity that frequently affects the patient's marriage, children, occupation, and other aspects of the patient's life. Few studies have examined the functional impairment in patients with affective illness. Earlier outcome studies of mania reported favorable long-term outcomes. However, modern outcome studies have found that a majority of bipolar patients evidence high rates of functional impairment. These low reports of functional recovery rates are particularly surprising. The basis for such limited functional recovery is not entirely clear. Factors associated with functional dysfunction include presence of inter-episode symptoms, neuroleptic treatment, lower social economic class, and lower premorbid function. Cognitive dysfunction, a symptom domain of schizophrenia, has been identified as an important measure of outcome in the treatment of schizophrenia. Recently, there has been some suggestion that there may be impaired neuropsychological performance in euthymic patients with recurring mood disorders. Whether impaired neuropsychological performance in associated with the functional impairment in bipolar patients who have achieved syndromal recovery is an intriguing question. The literature on functional impairment and cognition in bipolar disorder is reviewed.