The authors of this paper do not have any commercial associations that might pose a conflict of interest in connection with this manuscript.
Polarity at illness onset in bipolar I disorder and clinical course of illness
Article first published online: 9 JAN 2009
© 2009 The Authors. Journal compilation © 2009 Blackwell Munksgaard
Volume 11, Issue 1, pages 82–88, February 2009
How to Cite
Forty, L., Jones, L., Jones, I., Smith, D. J., Caesar, S., Fraser, C., Gordon-Smith, K., Hyde, S. and Craddock, N. (2009), Polarity at illness onset in bipolar I disorder and clinical course of illness. Bipolar Disorders, 11: 82–88. doi: 10.1111/j.1399-5618.2008.00654.x
- Issue published online: 9 JAN 2009
- Article first published online: 9 JAN 2009
- Received 6 December 2007, revised and accepted for publication 2 April 2008
- affective disorder;
- bipolar disorder;
- onset polarity
Objectives: Studies have suggested that episode polarity at illness onset in bipolar disorder may be predictive of some aspects of lifetime clinical characteristics. We here examine this possibility in a large, well-characterized sample of patients with bipolar I disorder.
Methods: We assessed polarity at onset in patients with bipolar I disorder (N = 553) recruited as part of our ongoing studies of affective disorders. Lifetime clinical characteristics of illness were compared in patients who had a depressive episode at first illness onset (n = 343) and patients who had a manic episode at first illness onset (n = 210).
Results: Several lifetime clinical features differed between patients according to the polarity of their onset episode of illness. A logistic regression analysis showed that the lifetime clinical features significantly associated with a depressive episode at illness onset in our sample were: an earlier age at illness onset; a predominantly depressive polarity during the lifetime; more frequent and more severe depressive episodes; and less prominent lifetime psychotic features.
Conclusions: Knowledge of pole of onset may help the clinician in providing prognostic information and management advice to an individual with bipolar disorder.