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

77 Rapid-cycling bipolar disorderDespite the generally positive outcomes of the previously cited studies on theuse of lamotrigine in the treatment of rapid-cycling bipolar disorder, more controlledstudies with longer courses are needed to clarify the role of this promisingagent.LithiumDespite being the oldest among the pharmacological armamentarium in thetreatment of bipolar disorder, lithium continues to draw attention to its utilityas an effective agent in the treatment of different aspects and phases of thisdisorder, and especially in the rapid-cycling course. While some researchers continueto demonstrate and advocate for lithium efficacy in the treatment of rapidcyclingbipolar disorder (Baldessarini et al., 2000, 2002; Swann et al., 2000; Vigueraet al., 2001; Tondo et al., 2001), others have argued that lithium has a poor efficacyin treating rapid-cycling bipolar disorder, even when supplemented by antidepressantsand neuroleptics (Post et al., 2000; Bowden, 2001).Baldessarini et al.(2000) concluded, in a study evaluating the factors associatedwith rapid-cycling status, that this subtype of bipolar disorder was stronglyassociated with type II diagnosis, higher average pre-lithium episode frequencyand percentage time ill, and weakly with female sex, but not with greater overallmorbidity during treatment. In 360 DSM-IV BP-I (n ¼ 218), and BP-II (n ¼ 142)disorder subjects (64% women) followed over an average of 13.3 years, researchersevaluated factors associated with rapid-cycling status with bivariate and multivariatetechniques, and response to lithium maintenance treatment (recurrencerates, time ill, survival analysis of time to recurrence on lithium). Their resultsindicated that the rapid-cycling risk (15.6% of cases) was 5.1 times greater in BP-IIversus BP-I subjects (30.3% versus 6.0%), in minor excess in women versus men(17.9% versus 11.5%), and associated with premorbid cyclothymia, depressive firstepisodes, older onset age, and being employed or married. Before lithium, rapidcyclingversus non-rapid-cycling cases had more mean total (3.9 / 1.2), manic, anddepressive episodes/year, and greater percent time ill (60% versus 38%). Duringtreatment, prior rapid-cycling status was unrelated to time to first recurrence andother measures of morbidity and improvement, including percent time ill, althoughdepressive episodes were 2.7 times more frequent, and there was 13.7% less chanceof full protection from all recurrences in rapid-cycling cases. Limitations of the studyincluded that it was naturalistic, without random assignment or blind assessment.However, its length and the number of subjects studied make its conclusionsnoteworthy.On the other hand, Swann et al. (2000) reported that at least four previousdepressive or 12 previous manic episodes are associated with reduced antimanic