Systematic clinical methodology for validating bipolar-II disorder: data in mid-stream from a French national multi-site study (EPIDEP)

Background: This paper presents the methodology and clinical data in mid-st ream from a French multi-center study (EPIDEP) in progress on a national sa mple of patients with DSM-IV major depressive episode (MDE). The aim of EPI DEP is to show the feasibility of validating the spectrum of soft bipolar d isorders by practising clinicians. In this report, we focus on bipolar II ( BP-II). Method: EPIDEP involves training 48 French psychiatrists in 15 site s; construction of a common protocol based on the criteria of DSM-IV and Ak iskal (Soft Bipolarity), as well as criteria modified from the work of Angs t (Hypomania Checklist), the Ahearn-Carroll Bipolarity Scale, HAM-D and Ros enthal Atypical Depression Scale; Semi-Structured Interview for Evaluation of Affective Temperaments (based on Akiskal-Mallya), self-rated Cyclothymia Scale (Akiskal), family history (Research Diagnostic Criteria); and prospe ctive follow-up. Results: Results are presented on 250 (of the 537) MDE pat ients studied thus far during the acute phase. The rate of BP-II disorder w hich was 22% at initial evaluation, nearly doubled (40%) by systematic eval uation. As expected from the selection of MDE by uniform criteria, inter-gr oup comparison between BP-II vs unipolar showed no differences on the major ity of socio-demographic parameters, clinical presentation and global inten sity of depression. Despite such uniformity, key characteristics significan tly differentiated BP-II from unipolar: younger age at onset of first depre ssion, higher frequency of suicidal thoughts and hypersomnia during index e pisode, higher scores on Hypomania Checklist and cyclothymic and irritable temperaments, and higher switching rate under current treatment. Eighty-eig ht percent of cases assigned to cyclothymic temperament by clinicians (with a cut-off of 10/21 items on self-rated cyclothymia) were recognized as BP- II. Evaluation of this temperament by clinician and patient correlated at a highly significant level (r = 0.73; p <0.0001). Cyclothymia and hypomania were also correlated significantly (r = 0.51; p < 0.001). Limitation: In a study conducted in diverse clinical settings, it was not possible to assure that clinicians making affective diagnoses were blind to the various tempe ramental measures. However, bias was minimized by the systematic and/or sem i-structured nature of all evaluations. Conclusion: With a systematic searc h for hypomania, 40% of major depressive episodes were classified as BP-II, of which only half were known to the clinicians at study entry. Cyclothymi c temperamental dysregulation emerged as a robust clinical marker of BP-II disorder. These data indicate that clinicians in diverse practice settings can be trained to recognize soft bipolarity, leading to changes in diagnost ic practice at a national level. (C) 1998 Elsevier Science B.V. All rights reserved.