This document provides an overview of personality disorders as discussed in Chapter 18 of the textbook "The Personality Puzzle". It covers the key topics of what personality disorders are, the Diagnostic and Statistical Manual (DSM) system for diagnosis, the major personality disorder clusters and specific disorders, and issues in defining and organizing personality disorders. The objectives are to discuss personality disorders and their characteristics, bases for diagnosis including the DSM, the major disorders organized into three clusters, and the prototype model of diagnosis.