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Offending in psychiatric patients after discharge from medium secure units: prospective national cohort study

BMJ 2004; 328 doi: https://doi.org/10.1136/bmj.38075.467569.EE (Published 24 June 2004) Cite this as: BMJ 2004;328:1534

Rapid Response:

Violence Prediction and Management

Derek Gilligan (Forensic Psychologist)

Derek.Gilligan{at}hunter.health.nsw.gov.au

Forensic Services

Off Dora St

Morisset Hospital

Australia

NSW 2264


 


Violence Prediction and Management


The latest generation of risk assessment instruments have dispelled previous ideologies that useful predictions cannot be made about violent behaviour, however these predictions are not without error. This can be demonstrated by applying the base rate data of Maden et al’s (2004) study to the PCL-SV for violence prediction.

 

Based on the research of Douglas et al (1999), using a cut off score of 20 with a sensitivity of .7 and specificity of .6 calculates the following base rate interactions:

 


True positives

56.4%

True Negatives

4.2%

False Positives

1.6%

False Negatives

37.6%


 

Whilst Psychopathy is currently considered to be the most robust single predictor of violence (Monahan, Steadman, Silver, Appelbaum, Robbins & Mulvey, 2001), over-reliance on this factor for simply categorising individuals into groups of high and low becomes complicated as the construct is not amenable to treatment (Hare, Clark, Grann, & Thornton, 2000) and decisions regarding release are not without a reasonable degree of error.

 

It is suggested that conceptually, risk of violence is multi faceted and is not limited to over-reliance on single static factors and actuarial predictions. Rather, violence risk is best considered in the context of treatment, intervention and management and incorporates dynamic and contextual factors that are best determined by a process of structured clinical judgement.

 

Some dynamic factorsthat are amenable to intervention and linked to violence in the literature include insight, mental illness symptoms, and negative attitudes (inter alia). In addition risk of violence is inherently contextual and depends on where patients will reside, what kind of clinical services they will receive, their motivation and ability to establish a pro-social adjustment, their experience of adverse life events and so forth (Webster, Douglas, Eaves, & Hart, 1997).

 

In summary if we are to progress toward less oppressive and custodial mental health services the effective management of violence risk cannot stop at actuarial predictions but will reside in tailoring individual treatment and management strategies incorporating a multitude of factors depending on the identified needs of individuals. These factors need to be pitched within the context of services provided, and various political and legal climates.

 


References


Maden, A., Scott, F., Burnett, G., Lewis, H., & Skapinakis, P. Offending in psychiatric patients after discharge from medium secure units: prospective national cohort study. British Medical Journal. 2004:328:1534.

Douglas, K.S., Ogloff, R.P., & Grant, I. Assessing Risk for Violence Among Psychiatric Patients: The HCR-20 Violence Risk Assessment Scheme and the Psychopathy Checklist: Screening Version. Journal of Consulting and Clinical Psychology.1994.Vol 67: No6: 917-930

 

Monahan, J., Steadman, H., Silver, E., Appelbaum, P.S., Robbins, P.C& Mulvey, E.P. Rethinking risk assessment:the Macarthur study of mental disorder and violence. Oxford:Oxford University Press, 2001.

 

Hare, R.D., Clarke, D., Grann, M., & Thornton, D. Psychopathy and the predictive validity of the PCL-R: An international perspective. Behavioral Sciences and the Law.2000:18:623-645

 

Webster, C.D., Douglas, K.S., Eaves, D., & Hart, S.D. HCR-20:Assessing Risk For Violence:Version 2.Canada:British Columbia Forensic Psychiatric Services Commision, 1997.

Competing interests:
None declared

Competing interests: Kestrel (Medium Secure Unit)

30 June 2004
Derek G Gilligan
Forensic Psychologist
Kestrel (medium secure unit) Forensic Services Morisset Hospital Off Dora St Morisset NSW 2264