In this rejoinder the author responds to the commentaries to the chapter. While the commentaries favor taxomonetric/categorical vs. dimensional approaches, the author explores various possibilities to integrate these two perspectives. Such an approach would better fit research finding and allows for preservation of the merits of each approach. Such integration has to resolve such challenges as definition of conceptually and clinically meaningful dimensions, identification of the disorder-specific concepts that are not dimensional, conceptualization of orthogonal dimensions, and integration of the dimensional and categorical approaches through identification of moderators.

This chapter reviews and summaries current knowledge about the categorical model of personality disorders. It starts with the history of the concept from Greek philosophers and moves to the description of personality disorders in DSM-5. It then summarizes key strengths of the categorical approach. First, it provides examples of the disorder-specific concepts that help understand in depth individuals with individual disorders. Second, it reviews research findings that validate the association between personality disorders and functional impairment. Third, construct validity of each personality disorder is reviewed based on the criteria of validation of psychiatric disorders. Ability to test construct validity of each disorder is a unique feature of the categorical model. Fourth, the predictive utility of the categorical model documents that the categorical diagnosis of personality disorder predicts significant clinical and psychosocial outcomes and predicts some functional outcomes independent of the dimensional model. Fifth, clinical utility research on categorical model and its limitations is reviewed. Sixth, the chapter reviews limitations of the categorical model, such as (i) excessive diagnostic co-occurrence, (ii) phenomenological heterogeneity, (iii) arbitrary diagnostic thresholds, and (iv) inadequate coverage. The chapter offers possible resolutions to these limitations. The chapter concludes with discussion of possible future directions, including combining categorical and dimensional approaches.