How does borderline personality disorder affect management and treatment response of patients with major depressive disorder? A comprehensive review

Background: Borderline Personality Disorder (BPD) and Major Depressive Disorder (MDD) are two clinical conditions that often co-occur, sharing several neurobiological aspects and clinical features. Depressed patients with BPD frequently report marked dysphoria, anger, emptiness and fear of abandonment. All these elements make the clinical management of MDD in patients with BPD challenging. The purpose of the present manuscript is to summarize the current literature about the effect of BPD on treatment response and management of patients affected by MDD. Methods: A bibliographic research on the main databases (PubMed, Embase, PsycInfo, Isi Web of Knowledge, Medscape, The Cochrane Library) was performed selecting published papers from 1987 until 16^th April 2020 and 13 studies were finally included in this review. Results: Most of the studies focused on the response to antidepressants, psychotherapeutic treatments or their combinations in patients with both MDD and BPD. In general, the co-occurrence of BPD seems to be associated with a poorer response to MDD treatment. Limitations: The data are not often replicated and most of the studies focus on different treatments, so that it is difficult to compare them. Conclusions: The presence of BPD seems to hamper the achievement of symptom remission in MDD patients, while the combination of selective serotonin reuptake inhibitors (SSRI) and psychotherapy may represent a valid option to treat these patients. Future studies, however, will have to confirm more robustly the findings reported in the present article and to investigate other possible treatment strategies.