DSM-IV and ICD-10 personality disorders: a comparison of a self-report questionnaire (DIP-Q) with a structured interview

OBJECTIVE: Diagnosing personality disorders according to structured expert interviews is time-consuming and costly. For epidemiological studies, self-report instruments have several advantages. The DSM-IV and ICD-10 personality questionnaire (DIP-Q) is a selfreport questionnaire constructed to identify personality disorder according to DSM-IV and ICD-10. METHOD: The DIP-Q is validated vs a structured expert interview in a clinical sample of 138 individuals. In addition, prevalence rates yielded by DIP-Q among 136 healthy volunteers are assessed and compared to expected prevalence. RESULTS: For DSM-IV the agreement for any personality disorder as measured by Cohen's Kappa was 0.61 and 0.56 for ICD-10. Overall sensitivity for any personality disorder was for DSM-IV 0.84 and for ICD-10 0.85. However, specificity was lower: 0.77 and 0.70, respectively. When dimensional scores between self-report and interview for each personality disorder were compared, the intraclass correlation for the DSMIV entities was 0.37-0.87 and for the ICD-10 entities 0.33-0.73. Among healthy volunteers the base rate of personality disorders was found to be 14%. CONCLUSION: DIP-Q can be used as a screening instrument for personality disorders according to DSM-IV and ICD-10. Self-report questionnaires such as DIP-Q will probably play an increasingly important role in future epidemiological studies.