Background: Previous studies have suggested that bipolar disorder may be underdiagnosed, and that antidepressants may be over-utilized in its treatment.
Methods: Consecutively admitted patients (n =48) diagnosed with DSM-IV bipolar disorder, type I, (n = 44) or schizoaffective disorder, bipolar type, (n = 4) were interviewed systematically and their charts were reviewed to confirm diagnosis before admission. They were then treated according to systematic structured interview diagnoses. These data reflect the changes in diagnoses and treatment.
Results: 40% (19/48) were identified with previously undiagnosed bipolar disorder, all previously diagnosed with unipolar major depressive disorder. A period of 7.5+/-9.8 years elapsed in this group before bipolar diagnosis was made. Antidepressant use was high on admission (38%) and was reduced with acceptable treatment response rates. The adjunctive use of risperidone appeared to be a good treatment alternative.
Limitations: While diagnoses were made prospectively, treatment response was assessed retrospectively, and was based on non-randomized, naturalistic therapy.
Conclusions: Systematic application of DSM-IV criteria identified previously undiagnosed bipolar disorder in 40% of a referred population of patients with mood disorders, all previously misdiagnosed as unipolar major depressive disorder. Antidepressants appeared overutilized and risperidone was an effective alternative adjunctive therapy agent.