Assessing Personality Disorder
There are a number of recognised methods of formally diagnosing personality disorder, which are currently used in clinical practice. Diagnosis is most frequently completed by a suitably qualified mental health professional, in most cases this being a psychologist or a psychiatrist. In certain cases, informants other than the person being assessed may also be consulted, such as a parent or spouse. In fact, trying to obtain corroborative information becomes increasingly important when assessing an offender with antisocial or psychopathic characteristics. The most commonly used methods for assessing personality disorder are described below.
- Unstructured clinical interview:
Personality disorders may be diagnosed through the use of an unstructured clinical interview, guided by a diagnostic manual (e.g. DSM-IV). To establish a diagnosis, the person’s behaviour over time is evaluated and attempts are made by the assessor to establish the presence of the traits characteristic of the diagnosis in a range of contexts and situations.
- Psychometric Questionnaires
In order to standardise the assessment process, a number of self-report questionnaires have been developed and have demonstrated improved reliability over unstructured assessments. These include the Millon Clinical Multiaxial Inventory – 3rd Edition (MCMI-III) or the Personality Assessment Inventory (PAI). These questionnaires have the advantage of being relatively quick to administer, but they have been criticised for over diagnosing personality pathology.
- Semi Structured Interviews:
A further standardised approach to PD assessment makes use of semi structured interviews, such as the International Personality Disorder Examination (IPDE), Structured Clinical Interview for DSM Disorders (SCID-II) or the Psychopathy Checklist – revised (PCL-R). These interviews require training to administer, have a structured scoring system and direct the assessor to explore the diagnostic symptoms relevant to each disorder. Although these interviews are thought to be the most reliable way to diagnose personality disorders they often require several hours of interview time to complete. They also rely somewhat on the honesty and insight of the person being assessed (although corroborative file information is emphasized in the case of the PCL-R).
How to spot PD
There are a number of ways that personality disorder may be identified by practitioners and these are listed below. A range of sources should be consulted in considering the possible presence of personality disorder. At the very least this will require a review of the available file information, but ideally should also include an interview with the individual concerned as well as a consideration of their overall presentation.
Look out for any inconsistencies between self-report and factual file information.
• A diagnosis in the file
• Review the offence history
• Evidence of childhood difficulties
• Previous contact with mental health services.
Score the OASys PD screen
Consider interpersonal dynamics
Remember the 3 P’s.