Recent UK government proposals to reduce the risks posed by people with “dangerous” severe personality disorders (DSPD) include a controversial new legal framework for indeterminate detention. In a systematic review in this week’s issue of THE LANCET, Alec Buchanan and Morven Leese from the Institute of Psychiatry, London, UK, aimed to establish the degree to which those operating the framework will be able to predict which people will act violently in the future.
The authors reviewed published reports in which the accuracy of a clinical judgment or a statistically derived rating of dangerousness was validated by its use to predict the violent behaviour of adults in the community. The sensitivity and specificity of the procedures used by every study were calculated, and applied to the purported base rates of violence in people with DSPD. Using the average positive predictive power from 21 of 23 published studies, the authors estimate that six people would have to be detained for a year to prevent one violent act within that year.
In a hardhitting Commentary (p 1926), Frank Farnham and David James from the Royal Free and University College London Medical School, UK, state: “This finding should not come as a surprise. The forecasting of dangerousness remains like that of the weather-accurate over a few days, but impotent to state longer-term outcome with any certainty.” They add: “Psychiatry has already become more coercive, with the number of compulsory admissions from the community increasing by 70% over the 10 years from 1986 to 1996. It now threatens to assume an Orwellian air, as the socially undesirable risk indefinite incarceration in psychiatric (or pseudopsychiatric) institutions… These changes are not taking place in isolation. They reflect a gradual transformation over the past two decades in criminal justice and social policy, as the “culture of welfare” is replaced by the “culture of control”. It is not difficult to see where such changes will lead: one has only to look across the Atlantic to the USA. With more than 2 million people in prisons, and dangerousness used as a criterion for execution as well as preventive detention, society is no safer, and liberty dies a little.”
Contact: Dr Alec Buchanan, Department of Forensic Psychiatry, Institute of Psychiatry, De Crespigny Park,London SE5 8AF,UK;T) +44 (0) 20 7848 0123 or 7919 2659;F) +44 (0) 20 7848 0754;E) a.buchanan@iop.kcl.ac.uk
Dr David James, Department of Psychiatry and Behavioural Science, Royal Free and University College London Medical School, Royal Free Campus, London NW3 2PF, UK; T) +44 (0)7768 123574; F)+44 (0)20 8342 0806; E) david.james5@ntlworld.com
Journal
The Lancet