Detecting personality disorders in the prison population of England and Wales: comparing case identification using the SCID-II screen and the SCID-II clinical interview

The cross-instrument validity of the SCID-II screen and the SCID-II structured clinical interview was examined in a sub-sample of 496 male and female prisoners from a national survey in England and Wales. Participants completed the SCID-II screen and were interviewed two weeks later by clinicians using the SCID-II interview. The screen was adjusted on the basis of interview results. Diagnostic categories were compared before and after adjustment of the screen. Diagnostic cut-off adjustments to the screen resulted in moderate agreement between instruments for categorical and dimensional evaluations. The screen retained good internal consistency with improved discrimination between personality disorders and clinical syndromes following adjustment. The SCID-II screen is a valid self-report instrument for diagnosing personality disorders. It may be preferable for prison populations but is not a substitute for a structured clinical interview.