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

121 Recurrent brief depressionTable 5.3 Mood disorder with recurrent brief depression (RBD) versus mood disorderswithout RBD: associations with clinical characteristicsDependent variable OR P CI 95%Family history of depression 1.99 0.01 1.17 3.39Family history of mania 1.52 0.36 0.62 3.70Family history of anxiety 2.56 0.00 1.49 4.38Suicide attempts 1.29 0.43 0.69 2.40Lifetime treatment depression 2.12 0.01 1.22 3.68Seasonal depression 1.37 0.24 0.81 2.30OR, odds ratio; CI, confidence interval.Onset and courseIn all groups the age of onset of first symptoms was early, occurring in 90% of casesbefore the age of 21. A chronic course was mainly observed in major depression butnot in bipolar spectrum disorders, whose course patterns tended to be characterizedby recurrent episodes and very high rapid-cycling rates (80% or more).Overall, bipolarity was associated with seasonal depression. Seasonal depressionin fall and winter was markedly present in all the mood-disorder subgroups,especially in combined BP-II and combined MDD. Rapid-cycling depression wasalso strongly associated with these two subgroups (69% and 62% respectively);rapid-cycling depression was found in about half of the pure BP-II and MDD cases.Associations with other psychiatric disordersOverall, the combined groups showed significantly elevated comorbidity with allsubgroups of anxiety disorders, with the exception of agoraphobia. However, wefound no systematic relationship between substance abuse/dependence and RBD;but significant differences were found between bipolar and depressive spectrumdisorders. Table 5.3 shows the results of a logistic regression that tested associationsbetween all three combined groups (BP-II, Min-BP, MDD with RBD) versusthe pure groups (without RBD) of mood disorders (as dependent variable), withsome of the characteristics listed in Table 5.2 as independent variables. RBD wassignificantly associated with a family history of depression (OR ¼ 2.0) and anxiety(2.6) and double the lifetime treatment rate for depression (OR 2.1).PersonalityCombined bipolar and depressive groups (with RBD) demonstrated significantlymore personality disorders and certain personality traits, such as mood lability