Objective: To obtain a comprehensive view of the clinical epidemiology of bipolar I and II disorder in secondary-level psychiatric settings.
Methods: In the Jorvi Bipolar Study (JoBS), 1630 non-schizophrenic psychiatric in- and outpatients in three Finnish cities were screened for bipolar I and II disorders with the Mood Disorder Questionnaire. Diagnoses were made using semistructured SCID-I and -II interviews. Information collected included clinical history, current episode, symptom status, and other characteristics.
Results: A total of 191 patients with bipolar disorder (90 bipolar I and 101 bipolar II) were included in the JoBS. The majority of bipolar II (50.5%) and many bipolar I (25.6%) patients were previously undiagnosed; the remainder had a median 7.8 years delay from first episode to diagnosis. Despite several lifetime episodes, 26 and 58% of bipolar I and II patients, respectively, had never been hospitalized. A polyphasic episode was current in 51.3%, rapid cycling in 32.5%, and psychotic symptoms in 16.2% of patients. Mixed episodes occurred in 16.7% of bipolar I, and depressive mixed states in 25.7% of bipolar II patients.
Conclusion: Even in psychiatric settings, bipolar disorders usually go undetected, or recognized only after a long delay. A significant proportion of not only bipolar II, but also bipolar I patients are never hospitalized. Polyphasic episodes and rapid cycling are prevalent in both types. Depressive mixed states are at least as common among bipolar II patients as mixed episodes among bipolar I.