Quality and severity of depression in borderline personality disorder: A systematic review and meta-analysis.

Depression in borderline personality disorder (BPD) is hypothesized to be distinct in quality and severity. This paper provides a systematic review of depression quality, and a meta-analysis of depression severity in BPD patients compared to those with depressive disorders (DeDs) only. Based on a systematic literature search, 26 studies were identified for systematic review and 35 studies (3425 participants) were included for meta-analysis. The review focused on different forms of depressive symptoms, affective impairment, self-evaluation, and negative interpersonal experiences. The meta-analysis examined age, gender, presence of comorbid DeDs in BPD patients, and type of depression scale as moderators of effect sizes. Findings indicate that depression quality in BPD is characterized by higher anger/hostility and self-criticism. There was no significant difference in depression severity between BPD and DeD groups, and a high level of heterogeneity. Moderator analyses revealed lower depression severity in BPD patients without comorbid DeDs, but higher severity in BPD patients with comorbid DeDs compared to depressed controls. Our results suggest high variability in depression severity across BPD patients, point toward the consideration of comorbid DeDs, and lend partial support to a BPD-specific depression quality. We discuss difficulties in research on depression in BPD, and offer directions for future studies.