Abstract
Nowadays, it is apparent that personality disorder is a common condition. Some of the concepts of personality disorder that are currently in use are flawed and need to be revised. The aim of this article is to discuss the controversy created by the uncertainties in the current classification system and to suggest ways forward. In particular, the clinician needs to be aware of the importance of assessing personality abnormality in terms of a severity dimension, and of the ways in which such an abnormality can impact on treatments for other conditions. These changes in the notion of personality disorder are needed as, for the first time, a good evidence base is being established for potential treatments and these will be maximized if we have a classification fit for therapeutic purpose.