Diagnosis of psychopathology with and without an interview.

This research compared independent ratings of criminal psychopathy (Hare's Psychopathy Checklist, Hare, 1991) from National Parole Board case files alone with ratings based upon file information plus a semi-structured interview. Notwithstanding high interrater reliability using National Parole Board (NPB) case files alone (n = 35), Psychopathy Checklist (PCL-R) scores had to be prorated because 30% of the items could not be scored. Comparisons between file only and independent file plus interview ratings of criminal psychopathy for a larger sample (N = 120) resulted in relatively low interrater reliability. Interrater agreement for ratings of psychopathy with and without an interview was statistically significant (p < .006), yet 40% of the cases received different diagnoses when the different procedures were used. Contrary to earlier findings (Wong, 1988), file only PCL-R ratings were not routinely an underestimate of file plus interview PCL-R ratings.