Dangerous and severe personality disorder: An investigation of the construct.

Introduction of the construct "Dangerous and Severe Personality Disorder" (DSPD) by the UK Home Office and Department of Health has provoked strong debate and opposition. Its aims and that of proposed subsequent legislation was to enhance public protection by identifying and detaining a minority of persons with severe personality disorder who pose a high risk of serious sexual/violent offending. The most serious criticism was the ethical implication of allowing indefinite detention of people without criminal convictions. More recently, policy emphasis has shifted towards treatment. 1396 male prisoners serving sentences of 2+years for sexual/violent offenses were prospectively interviewed (personality disorders, psychopathy, and risk) at a mean follow-up of 2 years. The prevalence of DSPD was 15%. Significantly more re-offended. Five DSPD offenders would need treatment to prevent one violent act. Based on an estimate of attributable risk, successful treatment of DSPD could reduce violent re-convictions among DSPD offenders by 71% and violent/sexual re-offenses in the prison population by 27%. DSPD criteria correctly identify high risk prisoners but primarily through risk-related demographic features. DSPD does not accurately identify serious sexual/violent re-offenders. The DSPD programme may reduce major violent re-offending if treatment interventions prove effective.