Dexamethasone suppression test and Axis I diagnoses of inpatients with DSM-III borderline personality disorder.

To determine the relationship of Axis I diagnoses to the DSM-III diagnosis of borderline personality disorder, 100 consecutive admissions to an inpatient service were studied. Of the 27 patients labeled borderline, 14 were given an Axis I diagnosis of major depression (unipolar) compared with 8 of 73 nonborderlines; 73% (19 of 26) of all borderlines tested but only 46% (18 of 39) of nonborderlines had a positive DST (p less than .05). Few borderline patients received concomitant nonaffective diagnoses, and even fewer were given bipolar or schizoaffective diagnoses.