HL Deb 24 September 2002 vol 638 cc185-6WA
Lord Lucas

asked her Majesty's Government:

In the context of the draft Mental Health Bill, what evidence they are aware of as to the reliability and consistency of the diagnosis "dangerous severe personality disorder"; and whether they are aware of any studies which demonstrate biases in this diagnosis in terms of gender, social class, or (in respect of the distribution of each characteristic in the population as a whole) the "likeability" of the patient as perceived by the person making the diagnosis. [HL5312]

The Minister of State, Home Office (Lord Falconer of Thoroton)

"Dangerous severe personality disorder", or DSPD, does not exist as a clinical or legal diagnosis in its own right. There are no specific "DSPD" provisions in the draft Mental Health Bill. The term is a working definition. It is designed to cover individuals who show significant disorder of personality; present a significant risk of causing serious physical or psychological harm from which the victim would find it difficult or impossible to recover, (eg homicide, rape, arson; and in whom the risk presented appears to be functionally linked to the personality disorder.

A developmental process of assessment designed to operationalise the above criteria is currently being piloted at HMP Whitemoor. The assessment process is comprehensive and, within a 16-week period, a number of instruments for the assessment of serious re-offending and severe personality disorder are completed. Prisoners are also observed and clinical judgements are made about the functional relationship between their disorder of personality and their serious offending behaviour.

Due to the developmental nature of the assessment pilot and the fact that DSPD, as currently conceptualised, does not exist as a clinical disorder, no previous research has been conducted specifically into the reliability and consistency of its "diagnosis". However, the assessment pilot is currently being independently evaluated. The aims of the research, among others, are to evaluate the reliability of the process and to consider whether it is objective and does not discriminate against any particular group of individuals in respect of social, cultural or ethnic background. The evaluation does not consider the issue of gender because all prisoners eligible for the HMP Whitemoor pilot are male.

The assessment process for DSPD does, however, build upon an existing evidence base about the assessment of severe personality disorder and the risk assessment of dangerous offending behaviour. Research shows that the instruments that are being used as part of this process are consistent, in that different clinicians are highly likely to arrive at the same diagnosis, and the measures are also shown to be stable across time.

There is no known evidence to suggest that the tools used in the DSPD assessment process have a gender or social class bias. However, the evidence base on the assessment of dangerousness and severe personality disorder is evolving. Research is currently ongoing to consider these issues.

There is also no known research to suggest that the "likeability" of the patient, as perceived by the person making the diagnosis, influences the assessment. However, the need to guard against the possibility is well recognised. The assessment for DSPD therefore makes use of objective assessment tools in order to help eliminate, as much as possible, any subjectivity in the assessment process.