Comorbid anxiety in bipolar disorder: does it have an independent effect on suicidality?

OBJECTIVE Comorbid anxiety disorder is reported to increase suicidality in bipolar disorder. However, studies of the impact of anxiety disorders on suicidal behavior in mood disorders have shown mixed results. The presence of personality disorders, often comorbid with anxiety and bipolar disorders, may explain these inconsistencies. This study examined the impact of comorbid Cluster B personality disorder and anxiety disorder on suicidality in bipolar disorder. METHODS A total of 116 depressed bipolar patients with and without lifetime anxiety disorder were compared. Multiple regression analysis tested the association of comorbid anxiety disorder with past suicide attempts and severity of suicidal ideation, adjusting for the effect of Cluster B personality disorder. The specific effect of panic disorder was also explored. RESULTS Bipolar patients with and without anxiety disorders did not differ in the rate of past suicide attempt. Suicidal ideation was less severe in those with anxiety disorders. In multiple regression analysis, anxiety disorder was not associated with past suicide attempts or with the severity of suicidal ideation, whereas Cluster B personality disorder was associated with both. The results were comparable when comorbid panic disorder was examined. CONCLUSIONS Comorbid Cluster B personality disorder appears to exert a stronger influence on suicidality than comorbid anxiety disorder in persons with bipolar disorder. Assessment of suicide risk in patients with bipolar disorder should include evaluation and treatment of Cluster B psychopathology.