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

6Atypical depression and its relation tobipolar spectrumFranco BenazziHecker Psychiatry Research Center, University of California in San Diego (USA) collaborating center, Ravenna, Italy;University of Szeged (Hungary); National Health Service, Forli, ItalyIntroduction: the relationship of atypical depression to bipolar II disorderThe focus of this chapter on the relationship between atypical depression (AD)(different definitions, including Diagnostic and Statistical Manual of MentalDisorders , 4th edn (DSM-IV): (American Psychiatric Association, 1994) definition)and bipolar (BP) spectrum is the relationship between BP-II and AD,because BP-II is the most common and best-studied disorder of the BP spectrumdisorders. BP-II was recently found to be very common in the community (11.0%BP-II versus 11.4% unipolar (UP): Angst et al., 2003) and in major depressiveepisode (MDE) outpatients (up to 60%: Cassano et al., 1992; Angst, 1996;Benazzi, 1997a, 2001a; Hantouche et al., 1998; Perugi et al., 1998; Akiskal et al.,2000; Benazzi and Akiskal, 2003a). But nevertheless BP-II is still underdiagnosed(Ghaemi et al., 2000). Lumping bipolar-I (BP I) and BP-II together is notsupported by the BP-II strong diagnostic stability (Coryell et al., 1995), differentfamily history (more BP-II than BP-I in first-degree relatives of BP-II) (Goodwinand Jamison, 1990; Coryell, 1999), and by linkage studies (McMahon et al., 2001).The most recent definitions of BP spectrum come from Akiskal and Pinto(1999), Ghaemi et al.(2002), and Angst et al.(2003). Akiskal and Pinto’s definitionincludes BP-I, BP-II (hypomania and MDE cyclothymic disorder), BP-III(antidepressant and stimulant-associated hypomania), and BP-IV (depressivemixed state, that is, a MDE plus some concurrent hypomanic symptoms). Thedefinition of Angst et al. (2003) includes BP-II, minor bipolar disorders (hypomaniaand mild depressions), and single hypomania (with no depression). Thediagnostic criteria of Ghaemi et al.(2002) for bipolar spectrum disorder include aUP MDE plus signs of bipolarity, such as bipolar family history, antidepressantinducedmania/hypomania, and AD. The bipolar spectrum disorder of Ghaemiet al. (2002) links pure UP with BP. Also depressive mixed state (Benazzi and# Cambridge University Press, 2005.