The prevalence of mixed episodes during the course of illness in bipolar disorder

Authors


Lars Vedel Kessing, Department of Psychiatry, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, DK 2100 Copenhagen Ø, Denmark.
E-mail: lars.kessing@rh.dk

Abstract

Objective:  To investigate the prevalence of mixed episodes during the course of illness in bipolar disorder.

Method:  A total of 1620 patients with an ICD-10 diagnosis of bipolar affective disorder at the first psychiatric contact were identified in a period from 1994 to 2003 in Denmark and the prevalence of mixed, depressive and hypomanic/manic episodes were calculated at each episode.

Results:  The prevalence of mixed episodes increased from the first episode to the tenth episode, however, only for women (6.7% of the first episodes leading to psychiatric care compared with 18.2% of the tenth episodes). For men, the prevalence of mixed episodes was constantly low. At all episodes, the presence of a current mixed episode increased the risk substantially of getting a future mixed episode.

Conclusion:  Clinicians should pay more attention to mixed episodes, especially among women, as they may represent an increasing treatment challenge as the illness progress.

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