Verbal fluency dysfunction in euthymic bipolar patients: a controlled study.

Objective: To study the executive functioning in euthymic bipolar patients in comparison to healthy controls and to examine the relationship between neuropsychological deficits and clinical variables.

Methods: Twenty-five euthymic bipolar patients and 31 controls underwent a battery of executive tasks including mental flexibility, inhibitory control and verbal fluency tests.

Results: There were no significant differences between bipolar patients and controls in relation to mental flexibility and inhibitory control. However, patients performed worse than controls on verbal fluency tests. Poor performances on the Stroop Test and the Hayling and Brixton Tests--part A were associated to lifetime occurrence of psychotic symptoms, prior number of episodes, and previous hospitalizations.

Conclusions: In our study, only verbal fluency tests differentiated bipolar euthymic patients from healthy controls. Patients who showed deficits in information processing speed and inhibitory control had more episodes and hospitalizations and lifetime occurrence of psychotic symptoms.