The clinical features of bipolar depression: A comparison with matched major depressive disorder patients

Background: Despite a resurgence of interest in the treatment of bipolar de pression, there have been few controlled studies of the clinical characteri stics of this condition. Identification of any distinctive clinical "signat ures" of bipolar depression would be helpful in determining treatment optio ns in the clinical setting. Method: From a cohort of 270 inpatients and outpatients assessed in detail during a DSM-IV major depressive episode, 39 bipolar I disorder patients wa re identified and closely matched with 39 major depressive disorder patient s for gender, age, and the presence or absence of DSM-IV melancholic subtyp e. Patients were compared on a broad range of parameters including the Hami lton Rating Scale for Depression (depression severity), 54 depressive sympt oms, the Newcastle Endogenous Depression Diagnostic Index. 3 family history items. 2 physical health items, the CORE scale (psychomotor disturbance), and 5 history items. Results: Although the bipolar patients were no more severely depressed than the major depressive disorder controls, they were more likely to demonstra te psychomoror-retarded melancholic and atypical depressive features and to have had previous episodes of psychotic depression. These findings were la rgely duplicated even when the population was confined to those with DSM-IV melancholia. Conclusion: The clinical admixture of pay chomotor-retarded melancholic sig ns and symptoms, "atypical" features, and (less frequently) psychosis may p rovide a "bipolar signature" in clinical scenarios when there is uncertaint y concerning the polarity of a depressive presentation.