Background: To estimate the frequency of bipolar disorder (BPD) among patients with a major depressive episode (MDE) and elucidate clinically-relevant factors predictive of bipolarity.
Methods: We evaluated 306 patients undergoing a MDE at facilities throughout Egypt. Patients were given the HCL-32 R2 questionnaire to assess the presence of manic/hypomanic symptoms; those scoring >14 were considered bipolar. We also investigated how various clinical criteria for bipolarity changed the incidence of bipolar diagnosis. Finally, we examined if demographics, psychiatric history, clinical characteristics, and the incidence of co-morbid conditions differed significantly between bipolar and unipolar patients.
Results: The positive screen rate for BPD based on HCL-32 R2 scores was 62.2% (188/302). However, only 26% (80/306) of patients had been diagnosed previously as bipolar. In contrast, when DSM-IV criteria were used, only 13.7% (42/306) of patients qualified as bipolar. A number of factors were highly predictive of bipolarity including: seasonality, number of past mood episodes, history of psychiatric hospitalization, mixed state, and mood reactivity. Of the comorbidities examined, only borderline personality disorder occurred at a higher rate in bipolar than in unipolar patients.
Limitations: Participating centers were not randomly selected and there could be a bias if only psychiatrists having specific interest in BPD were included.
Conclusions: The positive HCL-32-R2-based bipolar screen rate of 62% suggests that a substantial proportion of patients with a MDE may have BPD. Further, a number of factors in the patient's psychiatric history as well as clinical aspects of the episode itself may signal an increased likelihood of bipolarity.
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