Personality assessment

In their description of the Standardised Assessment of Personality – Abbreviated Scale (SAPAS) Moran et al (2003) write that, to the best of their knowledge, only two other interviewer-administered screens for personality disorder have been published. I would like to draw attention to a third, the Personality Structure Questionnaire (PSQ) (Pollock et al, 2001), which consists of eight bipolar items scored 1–5 and is similarly quick to administer and to score. The scores of four clinical and four non-clinical samples are reported in the paper. Two samples of patients meeting diagnostic criteria for borderline personality disorder had mean scores of over 30, whereas the non-clinical samples scored between 19.7 and 23.3. Scores on the PSQ were shown to correlate with a number of measures of multiplicity, dissociation and identity disturbance.

Most of the items on the questionnaire describe the respondent's awareness of a discontinuous sense of self. This reflects the multiple self states model of borderline personality disorder (Ryle, 1997a ), in which alternations in the operation of recognisable, discrete self states, each with a characteristic mood, sense of self and mode of relating to others, are seen to account for much of the experience and confusion of patients and of those treating them. The PSQ is similar to the SAPAS in being a screening, not a diagnostic instrument. It differs in that it focuses on the specific feature of self state instability typical of Cluster B disorders. This can be an advantage in that these patients present the greatest difficulty to clinicians. By drawing attention to this characteristic the PSQ can initiate further enquiry leading to the detailed description of an individual's self states and state switches, which can provide a basis for management and treatment directed towards personality integration (Ryle 1997b ).