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

117 Recurrent brief depressionThere was considerable stability of RBD over the years; 31% of RBD casesreceived a diagnosis of RBD again in a later interview.Three of 23 cases of RBM (11.5%) were followed by BP-II disorder, and 8% ofthe 38 cases with BP-II disorder were preceded by RBM.Of the subjects with hypomanic symptoms, seven of 122 cases (5.7%) developedBP-II disorders prospectively; in a follow-up, seven of 38 BP-II cases (18%) werefound to have manifested hypomanic symptoms in earlier interviews.Combined versus pure mood disorders (Table 5.2)GenderA marked female preponderance (88%) was only found in combined majordepression (MDD þ RBD). In most other groups with sufficiently large numbers,the female preponderance was marginal (53–60%).Diagnostic overlapRBM overlapped with pure BP-II disorder, combined BP-II, and combinedMinBP in about 20% of cases; if symptoms (RBMS) were included, that overlaprose to about 35%.The group of pure MinBP (without RBD) is small and not conclusive. The highrates of RBA (40–59%) among all subgroups of mood disorders associated withRBD are remarkable; this is compatible with the high odds ratio (OR) of 5.2 shownin Figure 5.3.Family historyFrom a genetic point of view, the results are very interesting: they demonstratethat, compared to pure BP-II and pure MinBP, the combined-disorder groupstended to have higher rates of positive family histories for mania, depression, andanxiety. It is important that, compared to the control group, none of the puredepressed groups had an elevated rate of a family history of mania.Clinical characteristicsA number of variables reflect the severity of the illness. Most demonstrate thegreater severity of illness in the combined groups: higher rates of subjective orsocial consequences of their hypomanic symptoms (therefore meeting moreoften the strict criteria for hypomania), higher rates of treatment and medicationfor depression, and higher distress scores due to depression. On the other hand,none of the subjects reported being distressed in any way by hypomanicsymptoms.