Is bipolar disorder specifically associated with aggression?

Objective: Several studies have suggested that bipolar disorder (BP) in adults is associated with aggressive behaviors. However, most studies have included only inpatients and have not taken into consideration possible confounding factors. The goal of the present study was to compare the prevalence of aggression in subjects with BP compared to subjects with other, non-BP psychopathology and healthy controls.
Methods: Subjects with bipolar I disorder (BP-I) and bipolar II disorder (BP-II) (n = 255), non-BP psychopathology (n = 85), and healthy controls (n = 84) were recruited. Aggression was measured using the Aggression Questionnaire (AQ). Group comparisons were adjusted for demographic and clinical differences (e.g., comorbid disorders) and multiple comparisons. The effects of the subtype of BP, current versus past episode, polarity of current episode, psychosis, the presence of irritable mania/hypomania only, and pharmacological treatment were examined.
Results: Subjects with BP showed significantly higher total and subscale AQ scores (raw and T-scores) when compared to subjects with non-BP psychopathology and healthy controls. Exclusion of subjects with current mood episodes and those with common comorbid disorders yielded similar results. There were no effects of BP subtype, polarity of the current episode, irritable manic/hypomanic episodes only, or current use of pharmacological treatments. Independent of the severity of BP and polarity of the episode, those in a current mood episode showed significantly higher AQ scores than those not in a current mood episode. Subjects with current psychosis showed significantly higher total AQ score, hostility, and anger than those without current psychosis.
Conclusions: Subjects with BP display greater rates of anger and aggressive behaviors, especially during acute and psychotic episodes. Early identification and management of these behaviors is warranted.
(© 2012 John Wiley and Sons A/S.)