Brief Communication: Criterion Validity of the Personality Diagnostic Questionnaire-4+ (PDQ-4+) in a Mixed Psychiatric Sample

Three hundred consecutively admitted in- and outpatients were administered the Personality Diagnostic Questionnaire-4+ (PDQ-4+). The Structured Clinical Interview for DSM-IV Axis II Personality Disorders, Version 2.0 (SCID-II) was used as the external diagnostic standard for personality disorder (PD) assessment. SCID-II was administered blind to PDQ-4+ scores. Low agreement between PDQ-4+ and SCID-II was observed for both dimensional and categorical PD evaluations. Receiver operating characteristic (ROC) analysis showed a definitively satisfactory discriminatory capability only for two PDQ-4+ PD scales (dependent, and antisocial). In agreement with previous studies, these results showed that PDQ-4+ was not a substitute for a structured diagnostic interview.