Towards a new perspective on personality disorder classification The alternative model for personality disorders in clinical practice

The Alternative Model for Personality Disorders (AMPD) constitutes a new and radically different PD classification system. It is a shift towards dimensionality, describing underlying impairments and traits. The research base of the AMPD model has been growing extensively. Research on validity and clinical utility of the model however is still scarce. This thesis aims to address this gap in the research base and focusses on the validity and utility of the AMPD model in clinical practice. The first part of this thesis describes the evaluation of several instruments for assessing Criterion A and the impact of using the model on case-identification of PDs. The second part of this thesis focuses on implementation and clinical utility of the model. The third part of this thesis focuses on a comparison of the AMPD model to the traditional Section II PD model in terms of predictive validity and clinical utility. The present thesis provided largely favorable psychometric results for both self-report and clinician-rated interview methods for assessing the AMPD. Compared to the Section II PD assessment, the AMPD assessment, in particular the LPFS is a promising tool for detecting PD early. Furthermore, compared to the Section II PD model, the LPFS may be superior in capturing vulnerabilities of patients that are predictive of general malfunctioning. With regard to utility of assessment, the present thesis provides a first insight into what makes PD assessment useful for patients: feeling less stigmatized, providing insight, enhancing hope and motivation for treatment, collaboration, and transparency.