Personality disorders in a Dutch forensic psychiatric sample: convergence of interview and self-report measures.

Convergence of PDQ-R- and SIDP-R-derived personality disorder diagnoses was studied in a sample of 85 forensic psychiatric patients. For categorical diagnoses, the mean kappa was .34, but on a dimensional level convergence was somewhat higher. Paranoid, antisocial and borderline personality disorders had prevalence rates around 40%; the other personality disorders occurred with much lower frequency. The PDQ-R yielded more diagnoses, except for antisocial, histrionic, narcissistic, and sadistic personality disorder. Because the latter disorders are among the most prevalent in forensic settings, and because they have important risk and treatment implications, the PDQ-R is not suitable as a screening device in forensic populations. Semistructured interviews that make use of collateral information are recommended for diagnosing personality disorders in forensic subjects.