Although many nosologists advocate the autonomy of borderline personality disorder (BPD), its heterogeneity led to demands that it be absorbed into the affective disorder spectrum. This study attempted to determine if (a) BPD and affective disorders overlapped and (b) if BPD characteristics were differentially associated with specific Axis I, DSM-III diagnoses. Forty-three BPD inpatients were rated retrospectively on 29 variables, including BPD characteristics from Gunderson’s diagnostic interview for borderlines (DIB). χ2 analyses were performed for each of 28 variables in 56 contingency tables whose independent variables were dysthymia/other Axis I diagnoses or depression/no depression. BPD inpatients with dysthymia had more impaired occupational functioning and greater use of splitting. Also, depressed BPDs were in general more dependent, empty and bored, and suicidal.