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

149 Atypical depression and bipolar spectrumclinician’s training, and to different study settings. Lower age of onset and morefemales in AD versus non-AD were reported (American Psychiatric Association,2000; Angst et al., 2002). More DMX in AD versus non-AD is a relatively newfinding (Benazzi, 2001g; Benazzi and Akiskal, 2001). However, more irritability (ahypomanic symptom) was also reported by Posternak and Zimmerman (2002),Akiskal (1996, 2000) reported that BP-II depression frequently had a combinationof AD and hypomanic symptoms, and DSM-IV-TR (American PsychiatricAssociation, 2000) stated that BP-II females were more likely to have mixedepisodes. Much more BP family history in AD versus non-AD is an importantfinding, as family history is an important variable, validating a diagnosis (Robinsand Guze, 1970). The review of Rabkin et al. (1996) concluded that, if AD wasrelated to BP, family history should show more BP. To test if the associations ofAD and female gender, early onset, DMX, and BP family history were specificfeatures of AD, or were instead due to its association with BP-II (which was closelyrelated to all these variables), multivariate logistic regression was used. Resultsshowed that the associations between AD and female gender, AD and early onset,and AD and DMX were specific features of AD and were not related to theassociation between AD and BP-II, but that the association between AD and BPfamily history was related to the association between AD and BP-II.It was found that the association between AD and axis I comorbidity was notspecific for AD, but could instead be related to a common early age of onset. It wasfound that the association between AD and BP-II was specific for AD and notrelated to a common age of onset. Two-way ANOVA was also used to find if thelower age of onset in AD versus non-AD was related to an interaction between ADand BP-II, showing such an interaction. Discriminant analysis of BP-II, femalegender, early onset, DMX, and BP family history for predicting AD found that ADwas significantly associated only with female gender, early onset, and DMX,supporting the previous multivariate logistic regressions, and suggesting that ADmay not be so strongly related to BP-II when compared to these predictor variables.BP-II AD, versus UP AD had a significantly lower age of onset, morerecurrences, more depression chronicity, more DMX, more BP family history,and more irritability, while AD symptoms were not significantly different. Resultssuggest that BP-II AD may be distinct from UP AD, supporting a DSM-IVclassification, where AD is not a distinct mood disorder. AD had a high specificityfor predicting BP-II, second only to BP family history, when compared to BPfamily history, early onset, many MDE recurrences, and DMX (which are typicalbipolar signs: Benazzi and Akiskal, 2001; Ghaemi et al., 2002). Discriminantanalysis of AD, BP family history, early onset, many MDE recurrences, andDMX for predicting BP-II diagnosis found that AD was a near-significant predictorof BP-II compared to the other variables.