The study of personality disorders was once thought to be a subject that should be abhorred by psychiatrists, as these disorders were not part of mainstream psychiatry. These conditions were considered untreatable and, as they were a measure of social deviance, they should occupy the attention of the legal and social service systems rather than the healthcare one. If psychiatrists were alienists (their old title) among other doctors then personality disorders were the aliens of psychiatric classification.

We are glad to say that this attitude has changed in recent years and the change in no small measure has been a consequence of opinion-formers such as Joel Paris, who has played a major part in dragging personality disorder to centre stage to be examined in the spotlights of scientific criticism, validity, reliability and utility. Professor Paris manipulates these spotlights well and shows that the psychiatric classification of personality disorders, despite several imperfections that need attention, has improved and that they can be discussed with confidence as an observable and reliable entity rather than as a pejorative prescription of someone the clinician does not like.

He also shows that personality disorders have many facets and that biological and social hypotheses need to be integrated to explain them. Genetic endowment, early and late childhood experiences, the quality of attachments to key figures, and consistency of upbringing are all influences that modify temperament into fully formed personality and Joel Paris shows how healthy processes can easily be distorted into maladaptive ones.