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

111 Recurrent brief depressionRecurrent brief psychiatric syndromesAlthough the relevant concepts were established a decade ago, recurrent briefpsychiatric syndromes are still not fully researched. They are characterized by aspecial course pattern, with frequently recurring (at least monthly) brief episodes,lasting between a few days and less than 2 weeks. Recurrent brief mood and anxietydisorders include recurrent brief hypomania (RBM) (Angst, 1992), RBD (Angst,1988), and recurrent brief anxiety (RBA) (Angst and Wicki, 1992). Recurrent briefpsychiatric syndromes were not conceptualized as new disorders but as elements ofthe manic, depressive, and anxiety spectra. Diagnoses of RBD and MDD are notmutually exclusive in our studies. In the same year a patient may manifest anepisode of MDD and many brief episodes of depression, qualifying for RBD. Theassociation may also be found during the course of an illness over years. Thecombination of recurrent brief psychiatric syndromes with the correspondingmajor disorders, for instance major depression, bipolar disorder, panic disorder,or generalized anxiety disorder, has great clinical relevance in terms of impairmentand treatment.Associations of RBD with MDDs were termed early on ‘‘combined depression’’ byanalogy with ‘‘double depression’’ (MDD þ dysthymia; Montgomery et al., 1989,Merikangas et al., 1990). Combined depression (CD) has been shown to be moresevere than pure MDD in the community (Angst et al., 1990) and in clinical samples(Pezawas et al., 2002b). The increased risk of suicide attempts and the severe clinicalcondition observed in CD are intriguing, since CD does not differ from either MDDor RBD with respect to the required psychopathological depression criteria. It isimportant for the understanding of the concept to bear in mind also that thehierarchy of the DSM-IV system, for example, determines that patients with either‘‘pure’’ MDD or CD are both diagnosed as MDD. We may therefore assume that thissubgroup of depressive patients may have contributed more than ‘‘pure’’ MDD toclinical impairment in DSM-IV-based studies on MDD.This chapter begins by analyzing the associations between RBD (Angst, 1988),RBM (Angst, 1992), and RBA (Angst and Wicki, 1992). All three recurrent briefpsychiatric syndromes share an ultrarapid cycling pattern of mood symptoms. Inassociation with MDEs, they clearly increase impairment and worsen treatmentoutcomes. Given this greater clinical severity of CD, it is reasonable to hypothesizethat BP-II disorders combined with RBD also represent more severe clinicalconditions than pure BP-II forms. The main goal of this chapter, then, is to testthis hypothesis by comparing diagnostic subgroups of mood disorders with andwithout RBD in a large number of validating clinical variables, including familyhistory, course, personality, and comorbidity. Cases associated with RBD willhereafter be termed ‘‘combined’’ (e.g., combined BP II disorder, combinedMDD, combined MinBP).