Convergent and Discriminant Validity of Personality Disorder Prototypic Acts

The diagnosis of personality disorders is problematic, largely because of low interrater reliability. One proposal has been to increase the behavioral specificity of the diagnostic criteria by using prototypic acts. However, the methodology by which prototypic acts have been selected has relied solely on face validity. The convergent and discriminant validity of prototypic acts for the schizoid, histrionic, and obsessive-compulsive personality disorders was assessed in this study, using a sample of patients who were diagnosed with personality disorder symptomatology after a semistructured interview. It was demonstrated that some acts might indeed be useful as either inclusion or exclusion criteria but that others lacked convergent and/or discriminant validity. The results are discussed regarding the limitations of prototypic acts and the methodology by which they are developed.