Using the SWAP-200 in a personality-disordered forensic population: is it valid, reliable and useful?

Background: Treatment and risk management of forensic patients relies heavily on diagnosing psychopathology, yet the reliability of clinical diagnoses of personality disorder has been found to be only fair to low. Structured instruments for the global assessment of personality disorder are infrequently used in clinical assessments possibly due to their limited validity and clinical utility.

Aims/methods: The Shedler-Westen Assessment Procedure-200 (SWAP-200) was developed in an effort to address these limitations. Although good reliability and validity in relation to clinicians' diagnosis of personality disorder has been reported, to date the validity of this instrument has not been assessed in relation to other standardized instruments or in a personality-disordered, forensic population. This study aims to establish the reliability and validity of the SWAP-200 against other diagnostic instruments and measures of interpersonal functioning in a personality disordered forensic population.

Results: This paper reports the results of 30 subjects from a high secure hospital in the UK who were assessed with the SWAP-200, the Structured Clinical Interview for DSM-IV Personality Disorders (SCID-II), the Adult Attachment Interview (AAI) and the Chart of Interpersonal Reactions in Closed Living Environments (CIRCLE). Preliminary results suggest that the SWAP-200 is a reliable instrument for the diagnosis of personality disorder in forensic patients.

Conclusions: Although the small sample size allows only preliminary conclusions about the validity of this instrument, early results show a reduction of the diagnosis of comorbidity compared with the SCID-II, together with an increased number of expected associations between independent measures of interpersonal functioning and categories of personality disorder.