Objectives: Bipolar disorder (BD) is recognized as a significant psychiatric condition worldwide, yet little is known about cross-national differences in the course of illness. This information might clarify features of the disorder that are illness versus culturally specific. Therefore, the aim of this study was to identify differential and shared outcome predictors in first-episode manic bipolar patients in Cincinnati, OH, USA and Taipei, Taiwan.
Methods: DSM-IV bipolar patients were identified at the time of their first manic or mixed episode and were prospectively followed in a naturalistic, longitudinal study for one year. Patients were recruited from a first psychiatric hospitalization at university-affiliated, urban hospitals in Taipei and Cincinnati. The primary outcome measures were remission, recovery, recurrence and percent of follow-up spent with affective symptoms and syndromes. Treatment adherence was also assessed, as were a number of possible mediator variables.
Results: The two patient groups showed a number of significant differences in index clinical presentation on characteristics previously associated with outcome in other studies (e.g., substance abuse). The patients in Taipei showed significantly better outcome on virtually all measures. Some of these findings reflected differences in index (mediator) variables, whereas others persisted after controlling for potential baseline confounds.
Conclusions: The early course of BD varies between Chinese and American patients. Some of this variance results from demographic and clinical cross-national differences in premorbid variables. Other sources of variance remain to be identified.