Affective Instability and Reactivity in Depressed Patients With and Without Borderline Pathology

The quality of depression in borderline personality disorder (BPD) was reported to differ from that in patients with major depressive disorder (MDD) only. However, little is known about affect dynamics in "borderline-depression." The authors assessed affective instability and reactivity in 20 MDD patients with BPD and in 21 MDD patients without BPD by Ambulatory Assessment. Participants reported on current affect, daily events, and attribution of affective states to events five times per day over a 7-day period. The results do not indicate higher affective instability in MDD patients with BPD comorbidity. Depressed patients with BPD reported less subjectively perceived affective reactivity, while observed associations between events and affect were not different between groups, except for one finding: In depressed patients with BPD, overall mood was lower after being alone. These findings suggest impaired attribution of mood changes and less tolerance of being alone as specific for depression in BPD.