Objectives: Bipolar disorder (BD) is correctly diagnosed in only 40–50% of patients. No previous study has investigated the characteristics of bipolar patients in psychiatric care with or without clinical diagnoses of BD. We investigated the demographic and clinical predictors of the absence of a clinical diagnosis of BD I and II among psychiatric patients.
Methods: In the Jorvi Bipolar Study, 1,630 psychiatric in- and outpatients were screened with the Mood Disorder Questionnaire. Suspected cases were diagnosed with the Structured Clinical Interview for DSM-IV Axis I Disorders-Patient version (SCID-I/P) for BD. Patients with no preceding clinical diagnosis of BD, despite previous manic, hypomanic or mixed phases and treatment in psychiatric care, were classified as undiagnosed. The clinical characteristics of unrecognized BD I patients (23 of 90 BD I patients) and BD II patients (47 of 93 BD II patients) were compared to those of patients who had been correctly diagnosed.
Results: No previous hospitalizations [odds ratio (OR) = 10.6, p = 0.001] or psychotic symptoms (OR = 4.4, p = 0.045), and the presence of rapid cycling (OR = 11.6, p = 0.001) predicted lack of BD I diagnosis. No psychotic symptoms (OR = 3.3, p = 0.01), female gender (OR = 3.0, p = 0.03), and shorter time in treatment (OR = 1.1, p = 0.03) predicted the lack of a BD II diagnosis.
Conclusions: Correct diagnosis of BD I is related to the severe phases of illness leading to hospitalizations. In BD II, the illness factors may not be as important as time elapsed in treatment, a factor that often leads to a delay in diagnosis or none at all. Excessive reliance on typical and cross-sectional presentations of illness likely explain the non-recognition of BD. The challenge for correctly diagnosing bipolar patients is in outpatient settings.