Objective: Bipolar disorder, a serious illness resulting in significant psychosocial morbidity and excess mortality, has been reported to be frequently underdiagnosed. However, during the past few years we have observed the emergence of an opposite phenomenon--the overdiagnosis of bipolar disorder. In the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, we empirically examined whether bipolar disorder is overdiagnosed.
Method: Seven hundred psychiatric outpatients were interviewed with the Structured Clinical Interview for DSM-IV (SCID) and completed a self-administered questionnaire, which asked the patients whether they had been previously diagnosed with bipolar or manic-depressive disorder by a health care professional. Family history information was obtained from the patient regarding first-degree relatives. Diagnoses were blind to the results of the self-administered scale. The study was conducted from May 2001 to March 2005.
Results: Fewer than half the patients who reported that they had been previously diagnosed with bipolar disorder received a diagnosis of bipolar disorder based on the SCID. Patients with SCID-diagnosed bipolar disorder had a significantly higher morbid risk of bipolar disorder than patients who self-reported a previous diagnosis of bipolar disorder that was not confirmed by the SCID (p < .02). Patients who self-reported a previous diagnosis of bipolar disorder that was not confirmed by the SCID did not have a significantly higher morbid risk for bipolar disorder than the patients who were negative for bipolar disorder by self-report and the SCID.
Conclusions: Not only is there a problem with underdiagnosis of bipolar disorder, but also an equal if not greater problem exists with overdiagnosis.