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

269 Comorbidity in mixed states and rapid-cycling disorderssome indication that they may (at least partially) result from an admixture of acertain personality type or a certain temperament to an affective episode – atheory that has been advocated most of all by Hagop Akiskal (Akiskal, 1996;Akiskal et al., 1998). There are now several studies supporting such a hypothesis(Dell’Osso et al., 1991; Akiskal et al., 1998; Brieger et al., 2003b), although theobserved differences between pure and mixed manic patients in respect to temperamentare not significant enough to explain the difference fully. Furthermore,methodologically, the distinction between mood ‘‘state’’ and temperament ‘‘trait’’cannot always be made satisfactorily. Concerning personality as assessed by thefive-factor model (Costa and Widiger, 1994), we found no difference betweenpatients with pure and mixed manic episode in a relatively small sample (Briegeret al., 2002b).We are not aware of any studies that have linked rapid cycling to the presence ofa personality disorder.Other psychiatric disordersThere is a large diagnostic overlap between attention-deficit hyperactivity disorder(ADHD) and bipolar disorder in children and adolescents (Geller et al., 2002b).Geller et al.(2002a, b, c) have outlined a ‘‘prepubertal and early adolescent bipolardisorder phenotype,’’ which may be superior to DSM-IV criteria in recognizingbipolar children and adolescents. Still, in their sample of 93 subjects with a‘‘prepubertal and early adolescent bipolar disorder phenotype,’’ 86.5% sufferedfrom comorbid ADHD, 87.1% showed rapid cycling (77.4% ultradian!), and54.8% presented with mixed mania. As only 16 of 93 subjects with bipolar disorderhad no ADHD, it seems futile to analyze the effect of comorbid ADHD on bipolardisorder. Rather, one has to acknowledge that (at least with the present diagnosticcriteria of ADHD), the great majority of childhood and adolescent cases of bipolardisorders present with rapid (and even ultradian) cycling and with co-occurringADHD, and that more than half of the subjects with bipolar affective disorderexhibit mixed episodes.We are not aware of any studies that have looked specifically at the relationshipbetween mixed states or rapid-cycling forms of bipolar affective disorders andeating disorders, sexual and gender-identity disorders, somatoform disorders, ordissociative disorders.Furthermore, we have not discussed the relationship between psychotic andschizophrenic disorders and ‘‘atypical’’ forms of bipolar affective disorders, as thislies outside the realm of this chapter. Where to draw the line between bipolaraffective disorders, schizophrenic disorders, and schizoaffective disorders is a