Cross-cultural comparisons on Wisconsin Card Sorting Test performance in euthymic patients with bipolar disorder.

We compared executive dysfunction with the Wisconsin Card Sorting Test (WCST) among distinct national and ethnic patients with bipolar disorder in euthymia. Bipolar patients, aged 16-45years, from the United States (n=25) and Taiwan (n=30) did not differ significantly on any measure. The WCST score for number Failure to Maintain Set was significantly positively correlated with residual affective symptoms in Taiwanese and US patients. Selective executive dysfunction in euthymia is inherent to bipolar disorder. Euthymic bipolar patients of various ethnic groups may exhibit similar executive dysfunction.