Today, the development of new technologies means that there are many advanced tools that can be used to improve our understanding of personality disorder, and, in turn, the treatment of personality disorder. One particularly promising tool — indeed, the focus of this chapter — is computerized language analysis. Through the exploration and analysis of verbal behavior, it is possible to empirically develop new insights into personality disorder, broadly defined. That is, by looking at patterns in the way that people with personality disorder use language — the words that they use and the way in which they use them — we can gain access into their broad constellation of thinking, feelings, and behaviors, as well as how precisely each of these features contributes to their pathology.

To date, however, there has been very little research at the intersection of verbal behavior and personality pathology. Accordingly, the goal of this chapter is to describe and discuss how personality disorder may become better understood through the application of natural language analysis, providing a rough roadmap for the development of personality disorder studies using modern methods. Specifically, in this chapter we will provide:

1. A brief background and overview of personality disorder;

2. An overview of how natural language processing (NLP) methods have advanced understanding within the wider field of psychology, focusing on personality psychology and psychopathology specifically;

3. Examples that demonstrate how NLP methods can help to resolve some of the fundamental, unanswered questions and debates in the personality disorder literature.