The identification of unipolar mania subtype based on anxiety comorbidity

Background: Unipolar mania is a controversial topic. Clinical research has focused on establishing specific characteristics that allow it to be distinguished from bipolar disorder (BD). Methods: Experienced and carefully trained clinicians evaluated a clinical sample of 298 patients with bipolar disorder using structured instruments to analyze the clinical and socio-demographics differences between people with manic episodes over the course of a 15-year illness compared with participants with histories of manic and depressive episodes. Results: According to adopted criteria, 16 (5.6%) participants presented unipolar mania (UM) and 282 participants presented manic and depressive (MD) phases. UM patients reported significantly more hospitalizations and medications, as well as more frequent psychosis at the first episode in the UM group than compared to the MD group. The UM group showed worse overall functioning, although differences in mood status between groups were not identified. Comorbid anxiety disorders and anxiety symptoms occurred significantly less frequently in the UM group. Limitations: Because of the cross-sectional design, determining causal relationships was not possible. Furthermore, the retrospective nature of the UM diagnosis could not exclude a future depressive episode. Conclusions: The presence of anxiety disorders can differentiate patients with unipolar mania from those with bipolar mania. (C) 2011 Elsevier B.V. All rights reserved.