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

93 Bipolar I and bipolar II: a dichotomy?we analyze all these data, it is essential to consider the influence of treatmentbecause many patients, before being diagnosed as bipolar II, could have beenmisdiagnosed as personality disorders or unipolar depressive disorder, whichwould have precluded the use of mood stabilizers that facilitated treatment withtryciclic antidepressants, with a high risk of drug-induced switching (Vieta, 1999).Figure 4.1 illustrates the natural course of some bipolar I and bipolar II patientswhen antidepressant use was strictly controlled and all patients received moodstabilizers.Coryell et al. (1987, 1995) reported that bipolar II disorder seemed to bephenomenologically stable, with a relatively low percentage of patients whobecame bipolar I during follow-up. This would support the long-term validity ofthe bipolar II category and the hypothesis of a true dichotomy. Akiskal et al.(1995)performed an 11-year follow-up of a sample who presented a major depressiveepisode. The results showed that 3.9% developed a full-blown manic episode,becoming bipolar type I, and 8.6% presented with at least one episode of hypomania,confirming that they belonged to bipolar II disorder. Unipolar patientswho switched to bipolar II disorder were characterized by early age at onset,recurrent depression, high rates of divorce or separation, high rates of scholasticand/or job maladjustment, isolated antisocial acts, drug abuse, and a broadmélange of atypical depressive symptoms with borderline taint. Mood labilitywas the most specific predictor of which depressions would prospectively switchto bipolar II disorder. The study testifies to the fact that bipolar II disorder is acomplex affective disorder with biographical instability deriving from an intensetemperamental dysregulation (Akiskal, 2002a, b). Other authors have suggestedthat the depressive phase of bipolar II disorder features more atypical symptomsthan unipolar depression (Benazzi, 2000). Akiskal et al. (1983) proposed eightcriteria that are believed to be predictive of ‘‘bipolarization’’ from depression:(1) treatment-induced hypomania; (2) family history of bipolar disorder; (3) stronginheritability; (4) depression with hypersomnia and motor slowing-down;Patients inremission(%)1008060402000 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24Bipolar IBipolar IIFig. 4.1 Course of bipolar I and bipolar II disorders. Reproduced with permission from Vieta (1999).