Measuring IPDE-SQ personality disorder prevalence in pre-sentence and early-stage prison populations, with sub-type estimates

Understanding the prevalence and type of personality disorder within prison systems allows for the effective targeting of resources to implement strategies to alleviate symptoms, manage behaviour and attempt to reduce re-offending. This study aimed to determine the prevalence of personality disorder (PD) traits within a local urban high-turnover adult male prison with a remand/recently sentenced population in London, UK. The International Personality Disorder Examination — Screening Questionnaire (IPDE-SQ) self-administered questionnaire (ICD-10 version) was completed by 283 prisoners (42% completion rate). 77% of respondents reached the threshold for one or more PDs. The most common PD types were Paranoid PD (44.5%), Anankastic PD (40.3%), Schizoid PD (35%) and Dissocial PD (25.8%). These results confirm and extend existing knowledge regarding the prevalence of PD in prison populations into a high-turnover, urban, remand population. The stark comparison with community samples indicates that a more equitable standard of service delivery within the criminal justice system, focussing on preventive and early intervention services, is now required.