Notes

The term “borderline” was introduced in the psychiatric literature by Stern1 and Knight2, to identify a patient group showing a level of functioning situated between neuroses and schizophrenic disorders. This patient group was not well defined. An important progress occurred with Kernberg's introduction of the concept of borderline personality organization3, 4, marked by the use of primitive defense mechanisms such as splitting or projective identification, identity diffusion (shifting between all-good and all-bad), and severely disturbed object relationships3. Reality testing was largely intact, differentiating individuals with borderline personality organization from psychotic patients3. Another early contribution was provided by Grinker et al5, who empirically identified four features of the “borderline syndrome”: anger, impaired close relationships, identity problems, and depressive loneliness.

In 1980, borderline personality disorder (BPD) was introduced in the DSM-III6, based on a study by Spitzer et al7, who drew both on research by Gunderson and colleagues8, 9 and on Kernberg's concept of borderline personality organization3, by including specific problems of identity and interpersonal relationships characterized by sudden shifts from one extreme to another (e.g., from all-good to all-bad or vice versa). This early research showed that BPD could be discriminated with sufficient accuracy from both schizophrenia and (neurotic) depression, as well as from other personality disorders10, 11.

In the following more than four decades, a plethora of research has been carried out on BPD, much more than on any other personality disorder. This research has focused on the diagnosis of BPD, its etiology (including genetics, neurobiology, and interactions between genetics/neurobiology and adverse childhood experiences), epidemiology, course and prognosis, cognition, and the effectiveness of pharmacotherapies and psychotherapies12-18.

BPD remains a challenging disorder, from both research and clinical perspectives. At present, for example, there is still controversy concerning its conceptualization as either a specific personality disorder or a level of general impairment in personality functioning19-21. The treatment of BPD remains challenging as well. As to pharmacotherapy, there is no consistent evidence showing that any psychoactive medication is efficacious for the core features of the disorder16. Indeed, no medications have been approved by regulatory agencies for treating BPD16, 22. According to the UK National Institute for Health and Care Excellence (NICE), pharmacotherapy should only be used to treat discrete and severe comorbid anxiety or depressive symptoms or psychotic-like features, or to manage acute crises, and should be administered for the shortest time possible22. Psychotherapy is the treatment of choice for BPD, with various approaches having proved to be efficacious in randomized controlled trials (RCTs)14, 17, 22. However, almost 50% of BPD patients do not respond sufficiently to psychotherapy23, so that further research in this area is clearly warranted. Whether specialized methods of psychotherapy or more generalist approaches are required for the treatment of BPD is a debated issue24-26.

This paper provides a comprehensive review of BPD diagnosis and clinical characterization, course, epidemiology, risk factors, neurobiology, social cognition and neurocognition, and management. Current controversies (e.g., categorical vs. dimensional approaches to diagnosis; specific vs. generalist psychotherapy interventions) are also discussed, and major areas in which further research is warranted are highlighted.