Clinical Features and Familial Aggregation of Social Relationships in Major Depressive and Bipolar Disorders in Southern Taiwan

Objectives: To investigate the demographic features and the distribution of symptoms for major depressive disorder (MDD), bipolar disorder type I (BPI), and bipolar disorder type II (BPII) families in Southern Taiwan, and to evaluate the familial aggregation of social relationships for the three diagnoses. Methods: A total of 290 probands (127, 43.8% BPI; 84, 29.0% BPII; and 79, 27.2% MDD) and 399 relatives participated in this study. Participants were interviewed by well-trained interviewers using the Composite International Diagnostic Interview (CIDI) in order to collect data about diagnosis, demographic and clinical features. Familial aggregation of social relationships were evaluated by the use of mixed models and intraclass correlation coefficients. Results: The female to male ratio was two to one in MDD and one to one in BPD. A higher proportion of MDD patients were married than were BPD patients. About ninety percent of all mood disorder patients had low socioeconomic status. Patients with BPD had an earlier age of onset and more depressive/manic episodes than did MDD patients. Probands with more severe impairments tended to have fewer contacts with friends. A familial aggregation of social dependence was observed in our sample. Conclusions: MDD and BPD patients have different clinical characteristics and familial aggregation of social relationships.