Risk and Mentally Disordered Offenders

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Research summary
Vol. 18 No. 4
July 2013


Are the risk factors for mentally disordered offenders different than for non-disordered offenders?


In recent years, correctional systems have seen a dramatic rise in the number of mentally disordered offenders, in Canada, 38% of new admissions to the Correctional Service of Canada reported a history and current high levels of psychological dysfunction. In the United States, the percentage of state inmates with a mental health issue rose from 16% in 1998 to 56% in 2005. A similar picture emerges in community corrections as seen in custodial populations and the findings are not limited to Canada and the United States. Outside of Canada and the United States, the proportion of offenders under community supervision (i.e., probation and parole) who have a mental disorder has been estimated to be as high as 53%.

The increasing numbers of mentally disordered offenders present a number of challenges for correctional staff. Decisions on security and supervision levels need to be made as well as placements into the appropriate treatment programs. Many of these decisions are facilitated with the administration of structured risk assessment instruments (see Research Summary, Vol. 2, No. 2). However, most risk assessment instruments used by correctional agencies were developed on non-mentally disordered, general offenders. Therefore, it is uncertain as to how appropriate these assessment instruments and the risk factors measured by the instruments are for mentally disordered offenders.


 A review of the research literature on risk factors among mentally disordered offenders was conducted. The review identified 126 studies completed between 1959 and 2011 and included both published studies in academic journals and more difficult to find studies (e.g., government reports, student dissertations). All of the studies had to meet certain methodological criteria that allowed for an evaluation of the various risk factors in the prediction of criminal recidivism.

The risk factors from the studies were grouped into two general domains. The first comprised the eight risk/need factors that have been shown to be important for general offenders (e.g., substance abuse, procriminal thinking, employment problems). The second domain consisted of mental health factors as possible predictors of recidivism. Examples are variables such as psychiatric diagnosis and prior psychiatric hospitalizations.

Both domains of risk factors were evaluated as to how well they predicted general and violent recidivism.


Nearly half of the studies in the review came from the United States with 23% from the United Kingdom and 15% from Canada. Schizophrenia was the most common diagnosis reported (47%) followed by a bipolar disorder (13%). The general recidivism rate was 39% and 23% for violent recidivism (average follow-up was 4.9 years).

There were sufficient studies to test only six of the eight risk/need categories for the prediction of general recidivism and five categories for violent recidivism. However, all of the risk categories found important for general offenders were also predictive for the mentally disordered offenders. This was true for both the prediction of general and violent recidivism.

Mental health variables were poor predictors of general and violent recidivism. For example, a diagnosis of schizophrenia and length of hospitalization did not predict recidivism outcome. Only a diagnosis of a personality disorder and antisocial personality disorder/ psychopathy predicted general and violent recidivism. This may not be surprising as antisocial personality contributes to one of the eight risk/need factors for general offenders (i.e., antisocial personality pattern).

Policy implications

  1. Risk assessments that are commonly applied to general offenders are likely relevant to mentally disordered offenders when the goals are to facilitate decisions around safety and security.
  2. Although mental health factors were not predictive of recidivism among mentally disordered offenders this does not mean that they do not play a role in correctional management. Mental health issues need to be addressed to alleviate personal psychological suffering experienced by many correctional clients.
  3. Correctional agencies need to integrate what the risk assessment research says about general offenders to inform their approach to assessing and managing mentally disordered offenders.  


For further information

James Bonta, Ph. D.
Corrections Research
Public Safety Canada
340 Laurier Avenue West
Ottawa, Ontario K1A 0P8
Phone: 613-991-2821 | Fax: 613-990-8295
E-mail: Jim.Bonta@ps-sp.gc.ca


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