Possible Dose-Side Effect Relationship of Antipsychotic Drugs: Relevance to Cognitive Function in Schizophrenia

Tomiki Sumiyoshi


Expert Rev Clin Pharmacol. 2008;1(6):791-802. 

In This Article

Disturbances of Cognitive Function in Schizophrenia

Several domains of cognition, such as verbal learning memory, attention and vigilance, executive function, verbal fluency and working memory, are impaired in patients with schizophrenia.[45–47] There is a large consensus that cognitive function, as specified earlier, is a major determinant of outcome in schizophrenia.[28] It should be noted that, among the cognitive domains, verbal memory is one of the best predictors of outcome in schizophrenia.[48,49]

We have reported recently that Japanese patients with schizophrenia also elicit an impaired performance on tests of various cognitive domains that is two standard deviations below the normative level on average Figure 4.[50,51] These data provide compelling evidence supporting the hypothesis that cognitive deficits in schizophrenia, reported mainly from English-speaking countries, are universal, particularly for performance on the verbal fluency tasks.[52–55]

Cognitive performance in schizophrenia as assessed by standardized neuropsychological battery. Patients with schizophrenia show a decline in cognitive function, (e.g., verbal memory, verbal fluency, attention and executive function). (A) Cognitive performance in schizophrenia as measured by the Brief Assessment of Cognition in Schizophrenia – Japanese Version (based on [50]). (B) Cognitive performance in schizophrenia as measured by the Toyama Psychopharmacological Study Battery (based on [51]).