Cognitive impairment and functional outcome in schizophrenia and bipolar disorder.

A considerable amount of evidence supports the relationship between cognitive impairment and functional outcomes in schizophrenia. Cognitive impairment is considered a core feature of schizophrenia that includes problems in speed of processing, attention/vigilance, working memory, verbal learning, visual learning, reasoning and problem solving, and social cognition. These deficits can also serve as an endophenotype for the illness in studies of genetics. Cognition is considered a reasonable treatment target in individuals with schizophrenia, partly because cognitive deficits contribute to poor functional outcomes. Similarly, evidence is beginning to emerge that cognitive impairment may also be a core feature of bipolar disorder. In addition, cognitive deficits adversely affect functional outcomes in bipolar disorder. This evidence suggests that cognition can be considered a reasonable target for intervention in both schizophrenia and bipolar disorder.