Original article The Maudsley bipolar disorder project Clinical characteristics of bipolar disorder I in a Catchment area treatment sample Vanessa Raymont, David Bettany, Sophia Frangou * Section of Neurobiology of Psychosis, P066, Division of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK Received in revised form 14 September 2002; accepted 6 December 2002 Abstract The clinical characteristics of bipolar I disorder (BD1) have prognostic and therapeutic importance. The aim of this study was to examine the effect of demographic and clinical variables on the course of BD1. We reviewed the case notes of all BD1 patients (n = 63) receiving treatment in a London psychiatric service during a 1-month period. Depressive and manic onsets were equally likely without any gender difference. The earlier the age of onset, the more likely it was for patients to experience psychotic features. Only depressive onsets predicted a higher number of episodes of the same polarity. Male gender and substance abuse were associated with younger age at first presentation, while women with co-morbid substance abuse had more manic episodes. Male patients were more likely than females to be unemployed or single. © 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. Keywords: Bipolar disorder; Co-morbidity; Gender; Clinical course 1. Introduction Bipolar disorder (BD) currently affects 0.8–1.6% of the population [7]. Its course is variable and a number of course modifiers have been identified. Co-morbid substance abuse [19,33] and psychosis [33,34] have been consistently found to predict poor outcome, while the impact of gender, age of onset and polarity of the first episode remains unclear [24,27,33]. There have been several attempts to identify course modifiers in BD in the hope that this may lead to more effective therapeutic interventions. Nearly all such observa- tions were based on patient populations from advocacy groups [15,17], research projects [31] and specialist mood clinics [27]. Although these studies have offered valuable insights, their sampling bias cannot be ascertained, thus lim- iting the degree to which their findings can be generalised. Therefore, in the present study, we focused on an unselected population of BD patients attending a secondary psychiatric service. To maximise the homogeneity of the patient popula- tion, we specifically examined patients with bipolar I disor- der (BD1). Our aim was to explore the effect of potential predictors of outcome, namely, gender, age of first presenta- tion, polarity of the first episode, presence of psychosis and substance abuse on the course of a representative group of BD1 patients. 2. Subjects and methods We performed a 1-month prevalence survey (April 1999) of all patients receiving treatment in a sector of the South London and Maudsley NHS Trust. The service surveyed provides secondary psychiatric care for a population of 67,650, aged between 15 and 64 years, who live in a fairly middle ranking area in terms of social deprivation. It has a Mental Illness Needs Index score [8] of 103.5, and an under- privileged area score [10] of –1.5. The national averages for these two indices are 100 and 0, respectively. 2.1. Population identification A psychiatrist screened the case notes of all patients (n = 425) receiving treatment by the service surveyed. Only pa- tients fulfilling the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) [1] operational criteria for BD1 were included in the study based on a best estimate diagnosis. The validity of the diagnosis was later confirmed * Corresponding author. E-mail address: s.frangou@iop.kcl.ac.uk (S. Frangou). European Psychiatry 18 (2003) 13–17 www.elsevier.com/locate/eurpsy © 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. DOI: 1 0 . 1 0 1 6 / S 0 9 2 4 - 9 3 3 8 ( 0 2 ) 0 0 0 0 9 - 3