Personality disorders are special. Currently they have their very own axis in the text revision of the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV-TR), but now we are told they may be relegated to Axis 1 or abandoned as a diagnostic category altogether. It all depends on decisions taken by the developers of the forthcoming edition, DSM-V. So now is the time for a diagnostic re-appraisal which is what this book is about. No one is satisfied with the current nomenclature; categories are crude, have limited validity and are considered stigmatising - once a ‘borderline’ always a ‘borderline’. Is there another way? This book suggests that there is.

The contributions to this book, some of which have already appeared elsewhere, are from a star cast of authors. All attended an international conference organised to discuss the classification of personality disorders with the aim of influencing the planners of the DSM-V. It is a nice thought that scientific enquiry will influence psychiatric classification; let's hope so.

There is a lot on offer here to inform the interested reader and to help the DSM-V team make their decisions. All authors agree that a move towards a classification system based on personality dimensions is warranted but there is no agreement about the essential dimensions. So how are we to choose them? Livesley tries to bring an aetiological approach to the choice of dimensions; Paris suggests using neurobiological evidence; others suggest a broader developmental approach. Each contribution has one or more commentaries allowing the less-informed reader to understand the problems associated with each approach. Importantly, there are discussions about cultural aspects of personality disorder which is a topic neglected within the hegemony of Western values and diagnoses. Severity comes under scrutiny too, although to a surprisingly limited extent given its importance. Services are being organised to target only the most severe cases which implies having robust indicators of severity; however, these are not available for most mental health problems let alone personality disorder.

Despite a tone of uncertainty throughout the book, it is possible to discern some consensus about the dimensions to be used even though many of the authors promote their own dimensional systems. The big five - neuroticism, extraversion, openness, agreeableness and conscientiousness - emerge as the major dimensions. The trouble starts once you have to decide the traits that best define these higher-order dimensions. There is no agreement. However, perhaps it won't matter to clinicians who are unlikely to be spending time trying to define the subtleties of neuroticism and openness. They make global judgements about higher-order dimensions of an individual's personality; if they can do that accurately, then using a dimensional approach will have some clinical utility. This is a theme taken up in a refreshingly practical comment from Roel Verheul who expresses some concern about proposed dimensional models, suggesting a hybrid model would be better. He argues that some clinical decision-making requires a cut-off; clinicians understand categories and any classification system needs the vote of the clinician if it is to enter widespread use and be useful for professional communication. He is concerned that dimensions will become too complex for the ‘jobbing’ clinician and so quickly fall into disuse in clinical practice. The focus on personality, stimulated so well by placing it on a separate axis in the current system, might then be lost to psychiatry.

Overall, there is well-informed debate in this book and it is to be recommended. It is a book for experts and those interested in personality disorder rather than someone coming new to the topic who is likely to be overwhelmed by the complexity of some of the discussion.