This volume presents the latest theory and research on the diagnosis and treatment of personality disorders. The chapters describe changes in the DSM-5 and ICD-11 assessment of personality disorders, review empirical support for these changes, and provide clinical guidance for diagnosing and treating the most common personality disorders. A primary focus throughout the book is the Alternative Model for Personality Disorders (AMPD), found in Section III (Emerging Measures and Models) of the DSM-5. The AMPD is a hybrid of the earlier categorical model of personality disorders and the emerging dimensional model fully embraced in the ICD-11. It offers a middle-of-the-road approach that is supported by a growing body of research. ​With its blend of research, clinical guidance, and case studies, this volume will be an essential resource for clinicians and researchers alike.