Relationship of trait impulsivity with clinical presentation in euthymic bipolar disorder patients

The purpose of this study was to examine trait impulsivity in patients with bipolar disorder and explore the possible connections between impulsivity and clinical presentation of the illness. Diagnoses were based on the Structured Clinical Interview for DSM-IV. The sociodemographic and clinical properties of 71 patients with bipolar disorder, who were euthymic according to Young Mania Rating Scale and Hamilton Depression Scale scores, were recorded. Their trait impulsivity was evaluated by using the Barratt Impulsiveness Scale (BIS) and impulsivity subscale of the Temperament and Character Inventory, and the results were compared with 50 age- and sex-matched healthy controls and among patients with different clinical properties. All BIS-11 subscale scores were higher in bipolar than in comparison subjects. There were no effects of education and age. Elevated BIS-11 scores were associated with predominant depressive polarity, longer duration of illness and a history of psychotic mood episodes and suicide attempts. These relationships persisted when age, gender, and education were taken into account. These results show that after accounting for common confounding factors, trait-like impulsivity was substantially higher in subjects with bipolar disorder than in nonbipolar comparison subjects and may vary according to different clinical presentations.