Bipolar Disorders: Mixed States, Rapid-Cycling, and Atypical Forms

113 Recurrent brief depressionbeen shown to have good diagnostic validity in depressed hospitalized and ambulatorypatients (Illes, 1981; Pfortmüller, 1983; Busslinger, 1984; Meier, 1985); aninterrater reliability study showed good specificity and sensitivity (Angst et al.,2003c) for the syndromes of depression and anxiety.DefinitionsBipolar spectrumA spectrum of bipolar disorders was defined as follows (for a detailed descriptionof the bipolar spectrum, see Angst et al. (2003a)):(1) BP-I disorder: DSM-IV criteria(2) BP-II disorders: Zurich criteria using two definitions:(a) a hard syndromal definition required the presence of hyperactive or moodsymptoms plus three of seven symptoms of mania plus personal or socialconsequences(b) a soft definition required only the presence of manic symptoms. Noepisode-length criterion was applied, as we could find no empiricalevidence for its validity(3) MinBP: the definition of MinBP required the diagnosis of dysthymia, minordepression (MinD), or RBD plus a hypomanic syndrome (a) or hypomanicsymptoms (b).(4) Cyclothymia was diagnosed in cases where dysthymia was combined withhypomania or hypomanic symptoms and where more days than not had beenspent in affective states during the 12 months prior to an interview.Depressive spectrumThe depressive spectrum was as follows:(1) MDD: DSM-IIIR(2) Dysthymia: DSM-IIIR(3) MinD: the diagnosis of MinD is often defined by any depressive symptomspresent over at least 2 weeks (Judd et al., 1994); in the Zurich study werestricted the definition to syndromes with three to four of the nine DSM-IIIR criterial symptoms, because under this threshold there was almost notreatment-seeking or impairment(4) RBD.Recurrent brief psychiatric syndromes(1) RBD required the presence of the major depressive syndrome according toDSM-IIIR symptom criteria (five of nine symptoms) with brief duration (less