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

99 Bipolar I and bipolar II: a dichotomy?TreatmentThere are few studies that compare bipolar I and bipolar II patients with respect totreatment response.Tondo et al. (1998) studied lithium maintenance treatment in bipolar I and IIpatients. Their findings showed that lithium had superior benefits in type II patients,with significantly greater reduction of episodes per year and of the percentage oftime ill. Reduction of depressive morbidity was similarly strong in both bipolar I andbipolar II diagnoses. In a recent study, Tondo et al.(2001) found similar results andconcluded that long-term lithium maintenance treatment in compliant patientswithout comorbid substance use-disorder remained effective, even in subgroups ofsupposedly poor prognosis, such as patients with mixed episodes, psychotic episodes,or rapid cycling. Only about a quarter of the patients in this study experiencedcomplete remission during maintenance treatment, suggesting that full protectionwas not commonly achieved with lithium or with alternative treatments. Someclinical factors found early in the course of illness (age at illness onset, and a longerinterval between first and second lifetime episodes) or early in treatment withlithium (rapidity of recovery from the index episode at the start of lithium treatment,and a longer interval to the first subsequent recurrence) were significantlyassociated with a better long-term treatment response as indicated by the overallproportion of time ill during treatment.Other studies found evidence of beneficial effects of lithium for both mania anddepression in bipolar I patients and for mainly depressive episodes in bipolar IIpatients (Dunner et al., 1976; Fieve et al., 1976; Quitlin et al., 1978; Kane et al.,1982; Peselow et al., 1982; Tondo et al., 1997). Koukopoulos et al. (1980)found significant differences in lithium prophylaxis as a function of episodesequence: the bipolar II patients with the hypomania–depression–euthymicinterval course were the best lithium responders. A higher incidence of axis-IIdisorders among bipolar II patients could affect drug responses. Other authors havereplicated the significantly more favorable prophylactic response among themania–depression–euthymic interval course (Grof et al., 1987; Haag et al., 1987;Maj et al., 1989; Faedda et al., 1991); in contrast, in the above-mentioned study ofTondo et al. (2001), the sequence of manic and depressive episodes was notassociated with treatment response. Goodwin and Jamison (1990) suggested thatthe poor results in patients with the depression–mania–euthymic interval coursemight reflect the impact of tricyclics given to treat depression; the mania followingdepression could be drug-induced, and such manias might be relatively resistant tolithium treatment.There was a suggestion for a higher prophylactic efficacy of carbamazepineversus lithium in bipolar II patients compared to bipolar I in one study (Greil et al.,