Personality disorders have been described as "the stepchildren of psychiatry". They have only recently been recognized as categories of psychiatric illness, and still need to be better defined. So far only the category of antisocial personality disorder has been fully validated, while schizotypal and borderline categories now have reasonable acceptance. This book interprets the personality disorders as products of the interaction between social influences and other etiological factors as part of a broad biopsychosocial model, and sets out to explain how personality traits develop into personality disorders. Strongly oriented towards recent empirical findings, the author's analysis leads him to question certain common assumptions about the origins of personality disorders, and in particular the simplistic notion that they may be traced back to dramatic childhood events. He argues that although biological, psychological, and social factors are all necessary, none of them is by itself sufficient to produce personality disorder. This basic model is also a model of treatment, in which biological, experiential, and social factors should all be addressed in therapy, and his treatment recommendations focus particularly on social adjustment through the adaptive use of personality traits. Illustrated with revealing case vignettes, this balanced, humane, and rational account of a difficult and sometimes contentious area will greatly assist clinicians in the understanding and treatment of individuals with personality disorder.