Personality disorder affects more than 10% of the population but is widely ignored by health professionals as it is viewed as a term of stigma. The new classification of personality disorder in the ICD-11 shows that we are all on a spectrum of personality disturbance and that this can change over time. This important new book explains why all health professionals need to be aware of personality disorders in their clinical practice. Abnormal personality, at all levels of severity, should be taken into account when choosing treatment, when predicting outcomes, when anticipating relapse, and when explaining diagnosis. Authored by leading experts in this field, this book explains how the new classification of personality disorders in the ICD-11 helps to select treatment programmes, plan long-term management and avoid adverse consequences in the treatment of this patient group.