WEIGHTING CRITERIA IN THE DIAGNOSIS OF A PERSONALITY-DISORDER - A DEMONSTRATION

This study focused on how clinicians combine symptom information about narcissistic personality disorder (NPD) to make a diagnosis. A sample of 59 psychiatrists and clinical psychologists were asked to read and diagnose 20 case histories of which 6 cases had criteria for NPD embedded as sentences. The number of criteria and the face validity of the criteria were varied across case histories. Three models of how criteria might be combined to form a diagnosis were compared: the polythetic model, the additive model, and the weighting model. The results were most consistent with the weighting model.