Research reportSystematic clinical methodology for validating bipolar-II disorder: data in mid-stream from a French national multi-site study (EPIDEP)
Introduction
Between the extremes of full-blown manic-depressive illness (BP-I disorder) and strictly defined unipolar depression (UP disorder), there exists a prevalent spectrum of `soft' bipolar conditions characterized by major depressive episodes with less than syndromal mania (Akiskal, 1983). Bipolar-II disorder (BP-II) defined by major depressive episodes with recurrent hypomanic episodes and/or cyclothymic temperament is the prototype of the soft bipolar spectrum (Akiskal, 1996). Despite its inclusion in DSM-IV, the diagnosis of BP-II is still difficult to make in practice (Dunner and Tay, 1993): clinicians trained to recognize it appear better in diagnosing it than those using structured interviewing.
Patients suffering from a BP-II disorder usually seek help when depressed and most of them are recognized as `unipolar' and treated with antidepressants without any protection against such potential negative effects as mood switching, cycling, mixed states, chronicization and associated treatment resistance (Koukopoulous et al., 1980, Akiskal and Mallya, 1987, Wehr and Goodwin, 1987, Stoll et al., 1994, Altschuler et al., 1995). European psychiatrists are in some disadvantage in this regard, because ICD-10 (in common use in Europe), tends to equate bipolarity with more or less clear-cut mania (World Health Organization, 1992). We felt that in this context, an awareness of the clinical presentations of the entire soft bipolar spectrum represents an important issue in clinical practice. The clinical and public health significance of this issue is further underscored by emerging data on the very high prevalence of this spectrum of disorders (Akiskal and Mallya, 1987, Koukopoulous et al., 1990, Goodwin and Jamison, 1990, Cassano et al., 1992, Benazzi, 1997).
Section snippets
Aim
The over-arching purpose of the EPIDEP, and its companion EPIMAN (Akiskal et al., 1998), studies is to assist practising psychiatrists, whether in private, community or university settings, to recognize bipolarity in all of its varieties: especially psychotic, mixed manic, and bipolar II forms.
Preparatory to the ambitious aim of obtaining national French data on the full spectrum of bipolar disorders, between April 1992 and December 1994, the first author (EGH) held 40 round-tables in 26
General characteristics
Sixty-two percent of patients with MDE were out-patients. Seventy-four percent were female, and mean age (±SD) was 46 (±13) years. For 74% of patients, the current episode was part of a recurrent illness, and 50% had been previously hospitalized.
Diagnostic distribution at visit I
Classification of mood disorders at the end of Visit I was as follows: 48% recurrent UP, 24% first MDE, 22% BP-II, and 6% BP-I. The mean score (±SD) on HAM-D scale was 27 (±6), and on the Rosenthal additive scale 8 (±3).
Assessment and diagnostic distribution at visit II
By this visit, the mean score
Discussion
The main finding of this study is the high prevalence of BP-II in the total cohort of major depressive in- and/or outpatients examined by 48 investigators in 15 different regions of France. Apart from the 22% of patients previously known to have BP-II disorder, a systematic search for hypomanic episodes revealed that an additional 26.5% of `unipolar'patients (20% of those with first MDE and 30% of those with recurrent MDE) could be diagnosed as BP-II. This yielded a total prevalence of 40% for
Conclusion
Many clinical investigators (Endicott et al., 1985, Akiskal, 1983, Akiskal, 1994, Coryell et al., 1995) have argued for the distinct nature of BP-II disorder, within the bipolar spectrum, culminating in the DSM-IV acceptance of BP-II two decades after its initial delineation (Dunner et al., 1976). The EPIDEP study was designed to help clinicians in their daily practice to make precise and astute subtyping of bipolar disorders. Results on the first 250 patients entered showed that
Acknowledgements
Professor H.S. Akiskal (San Diego, USA) was the international advisor in collaboration with a French scientific committee, which included Professor J.F. Allilaire (Paris), Professor J.M. Azorin (Marseille), Professor M.L. Bourgeois (Bordeaux), and Professor D. Sechter (Besançon). The study is coordinated by Doctor E.G. Hantouche (Paris) in collaboration with Drs. J.P. Fraud (now retired) and L. Châtenet-Duchêne (both from CNS Department-Sanofi), and supported by an unrestricted grant from
References (65)
- et al.
Cyclothymic temperament disorders
Psychiatr. Clin. North Am.
(1979) Subaffective disorders: dysthymic, cyclothymic and bipolar II disorders in the `borderline' realm
Psychiatr. Clin. North Am.
(1981)- et al.
Bipolar outcome in the course of depressive illness
J. Affect. Disord.
(1983) The prevalent clinical spectrum of bipolar disorders: Beyond DSM-IV
J. Clin. Psychopharmacol.
(1996)- et al.
Gender, temperament and the clinical picture in dysphoric mixed mania: Findings from a French national study
J. Affect. Disord.
(1998) Prevalence of bipolar II disorder in outpatient depression: A 203-case study in private practice
J. Affect. Disord.
(1997)- et al.
Proposed subtypes of bipolar II and related disorders: With hypomanic episodes (or cyclothymia) and with hyperthymic temperament
J. Affect. Disord.
(1992) - et al.
Diagnostic reliability of the history of hypomania in bipolar II patients with major depression
Compr. Psychiatry
(1993) Bipolarity: The iceberg of affective disorders?
Compr. Psychiatry
(1983)- et al.
Bipolar II. Combine or keep separate?
J. Affect. Disord.
(1985)