Unipolar mania: Identification and characterisation of cases in France and the United Kingdom.

Background: Unipolar mania is a putative subtype of bipolar disorder (BD) in which individuals experience recurrent manic but not major depressive episodes. Few studies of unipolar mania have been conducted in developed countries and none in the UK. This study aimed to identify and characterise people with unipolar mania in the UK and France.
Methods: People with unipolar mania were ascertained using a South London UK electronic case register and a French BD case series. Each unipolar mania group was compared to a matched group of people with BD who have experienced depressive episodes.
Results: 17 people with unipolar mania were identified in South London and 13 in France. The frequency of unipolar mania as a percentage of the BD clinical population was 1.2% for the South London cohort and 3.3% for the French cohort. In both cohorts, people with unipolar mania experienced more manic episodes than people with BD, and in the French cohort were more likely to experience a psychotic illness onset and more psychiatric admissions. Treatment and self-harm characteristics of people with unipolar mania were similar to people with BD.
Limitations: The relatively small number of people with unipolar mania identified by this study limits its power to detect differences in clinical variables.
Conclusions: People with unipolar mania can be identified in France and the UK, and they may experience a higher frequency of manic episodes but have similar treatment and self-harm characteristics as people with BD.
Competing Interests: Declaration of Competing Interest Dr. Stokes reports grants from the National Institute for Health Research and the Medical Research Council UK during the conduct of the study; grants and non-financial support from Corcept Therapeutics, non-financial support from Janssen Research and Development LLC, grants from H. Lundbeck A/S outside the submitted work. Dr. Yalin reports being an investigator in clinical studies conducted together with Janssen-Cilag, Corcept Therapeutics and COMPASS Pathways during the last 36 months. Mr. Mantingh has nothing to disclose. Dr. Colasanti has nothing to disclose. Dr. Patel reports grants from MRC, grants from Academy of Medical Sciences, during the conduct of the study. Prof Bellivier reports personal fees from Sanofi, outside the submitted work. Prof Kahn reports personal fees from Janssen-Cilag and other from Lundbeck, outside the submitted work. Dr. Leboyer has nothing to disclose. Dr. Henry has nothing to disclose. Prof. Etain reports grants from INSERM, grants from Assistance Publique - Hôpitaux de Paris, grants from Labex Biopsy, personal fees from Fondation Fondamental, during the conduct of the study. Prof. Young reports grants from Janssen, grants from Compass, personal fees from Livanova, personal fees from Lundbeck, personal fees from Otsuka, personal fees from Sunovion, personal fees from Bionomics, outside the submitted work.
(Copyright © 2019. Published by Elsevier B.V.)