Borderline personality disorder may be one of the most pleomorphic disorders in medicine. Patients with this diagnosis are a complex mixture of strengths and weaknesses that confuse the diagnostician and frustrate the psychotherapist. Such patients may seem charming, composed, and psychologically intact one day and collapse into suicidal despair the next. Impulsivity, affective lability, frantic efforts to avoid abandonment, and identity diffusion are all hallmarks of borderline personality disorder (although the name of the condition does not necessarily reflect these dimensions). Patients with borderline personality disorder often raise hope in the dedicated psychiatrist only to dash that hope by demonstrating that their apparent gains are illusory. Hatred and contempt may be directed at those who attempt to help them, leading to countertransference and feelings of exasperation and impotence.Although patients with borderline personality disorder were once seen as having an untreatable and irrevocably chronic disease, specially designed psychotherapies and adjunctive pharmacotherapies have resulted in a sea change in the psychiatric attitude toward these patients. Guided by a growing body of empirical research, psychiatrists can now feel guardedly optimistic about the outcome when a carefully thought out treatment plan has been implemented. The reasons for this sea change are comprehensively discussed in this first-rate book. John Gunderson is uniquely qualified to write this overview of borderline personality disorder. He was present at the birth of the diagnosis (i.e., its entrance into the official nomenclature), and his research had much to do with the establishment of borderline personality disorder as a bona fide psychiatric condition. Having also devoted much of his professional life to the treatment of patients with borderline personality disorder, he has successfully followed that rare dual-career path of rigorous researcher and active psychotherapist.One of the most compelling features of this book is the author's breadth of knowledge and his evenhanded consideration of various diagnostic and treatment perspectives. Although Gunderson has psychoanalytic training and is an expert in psychodynamic therapy for borderline personality disorder, he is open-minded in his consideration of other forms of treatment, such as ``dialectical'' behavioral therapy, group and family approaches, and pharmacotherapy. In chapter after chapter, he evaluates the strengths and weaknesses of all treatments with an admirable levelheadedness, giving credit where it is due while also pointing out the limitations of any conclusions drawn from the empirical approaches. Moreover, Gunderson is ready to drop personal bias and preferences when the data lead him in a different direction. When research is lacking, he fills the gap with abundant clinical wisdom and marvelously illustrative case examples. He lets the reader know what he actually says to patients in particular situations so that other clinicians can evaluate the merits of his approach.Gunderson also describes the typical course of treatment to help guide the reader through the various phases, each with its own set of goals. He is a firm believer in multimodal strategies, and he repeatedly stresses the value of having multiple clinicians involved in order to dilute the intensity of the transference and countertransference. Whereas the importance of families to intensive long-term treatment of borderline personality disorder was once marginalized, Gunderson strongly advocates the use of family interventions much like those proved so effective in the treatment of schizophrenia.Despite my overall positive impression of this book, I have several reservations as well. Gunderson uses idiosyncratic terminology that is likely to confuse some readers. Although the term ``boundary violation'' is generally used to describe ethical transgressions by clinicians, Gunderson uses it to describe acting-out behavior by patients who are testing the limits of the therapeutic frame. Unlike therapists, patients have no professional code of ethics to which they must adhere. The use of the term ``boundary violation'' is thus misleading and can be construed as blaming the patient.Gunderson also draws what I consider a specious distinction between treatments and therapies: ``treatments (e.g., medication, diet, hospitalization) are given to patients; a patient passively receives (or resists) but does not initiate. Therapies require shared goals and at least intermittent collaboration.'' From my point of view, hospitalization, diet, and pharmacotherapy require just as much collaboration as psychotherapy, and separating psychotherapy from the array of psychiatric treatments merely reinforces prejudices in the society at large that psychotherapy is not a ``real'' treatment. I also think that Gunderson defines dynamic therapy too narrowly, since he emphasizes that it may be incompatible with the setting of limits and the managing of safety -- tasks he relegates to a primary clinician involved in ``case management.'' Most dynamic therapists include generous helpings of management in their psychotherapeutic approaches to borderline personality disorder.My final reservation is one of form rather than content. Throughout the book a number of excellent points are made in sidebars to the text. I found that this approach interrupted the smooth flow of the narrative.Having stated my quibbles with the author, I would still recommend this book as the best state-of-the-art writing on the subject of borderline personality disorder. The clarity of Gunderson's prose style is marvelous for teaching purposes. Experienced psychiatrists and other mental health professionals will find it equally useful because of its combination of both a scholarly and a practical approach. Even families of patients with borderline personality disorder can gain a great deal from a careful reading of the book. I have always been reluctant to recommend books to patients and their families, but this one is an exception. Gunderson has managed to write a book that bridges the gap between professional clinicians and those they treat.Glen O. Gabbard, M.D.Copyright © 2001 Massachusetts Medical Society. All rights reserved. The New England Journal of Medicine is a registered trademark of the MMS.