In this paper the authors discuss the clinical diagnosis of personality disorders, using a multi-conceptual, multi-instrumental approach. This approach requires data collection from different conceptual domains with multiple assessment instruments for every domain in every patient.

The convergence of different concepts and assessment procedures was limited both at the population and the individual level. Divergent findings gave rise to new diagnostic questions, whereas convergent findings seemed to enhance treatment strategies.

In the discussion the authors advocate the development of diagnostic protocols that ensure the applications of both questionnaires and (semi)structured interviews in the diagnostic process.