The prevalence of severe personality disorder in perpetrators of homicide

Background Current UK evidence on the prevalence of personality disorder in homicide is lacking. The aims were to estimate the prevalence of personality disorder in homicide perpetrators from court reports and carry out a dimensional assessment in keeping with the new ICD-11 classification of the prevalence of severe personality disorder. Associations between severe personality disorder and sociodemographic, historical and offence-related characteristics were then explored. Methods Six hundred court reports from a national case series of homicide perpetrators in England and Wales were analysed using a document-derived version of the Personality Assessment Schedule (PAS-DOC), providing categorical and dimensional personality assessments. The prevalence of personality disorder and severe personality disorder was estimated. Factors associated with the diagnosis of severe personality disorder were examined. Results The prevalence of personality disorder using the PAS-DOC was 56.3% (95% confidence interval 52.3%, 60.3%), compared with 16% as diagnosed in reports. Severe personality disorder was present in 62% (n = 338) of all those with a personality disorder and was significantly associated with homicides of strangers and previous violence. Conclusions Severe personality disorder is highly prevalent among perpetrators of homicide, and the finding that it is more prevalent when strangers are the victims stresses both the need for early identification of those at risk of developing severe personality disorder and the development of appropriate early preventive interventions. There is also a need for the development of effective treatment and interventions for those with established severe personality disorder and better identification of this level of disorder by psychiatrists. The forthcoming ICD-11 classification should help in this endeavour. (c) 2021 The Authors Personality and Mental Health Published by John Wiley & Sons Ltd.