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An International Study of Crime and Violence Risk

Deborah Ross, MSc

Reprinted from "Criminal Justice" issue of Visions Journal, 2005, 2 (8), p. 32-33

Understanding community outcomes of people with serious mental illness

Although violence is a behaviour of concern among people with a serious mental illness, they are far more likely to be the victims of violence than they are to be violent themselves. Data collection for this study included information on victimization; further analyses will explore this topic area.

A number of large population­ based studies have shown increased rates of violent and nonviolent criminal offences among people with serious mental illness (SMI), in particular among those with schizophrenia.1 Additionally, higher rates of schizophrenia have been reported in prison populations than in the general population.2 While there is agreement that the social and economic costs of crime and violence are high, few studies have evaluated the impact of treatments and services on these outcomes.

In each of the four participating countries (Canada, Finland, Germany, Sweden), patients from civil psychiatric and forensic psychiatric hospitals were invited to participate. Participating patients from each of these hospital types were matched (on age, gender, diagnosis and ethnicity) so that individuals with similar characteristics could be compared across the different systems of care (i.e., civil vs. forensic). Baseline assessments—including chart reviews, interviews with patients and interviews with a family member or caregiver—provided information on social, demographic, clinical and risk variables. Follow-up assessments were completed every six months after discharge for a two­ year period.


Out of a total of 255 individuals participating in the international study,3 120 were from British Columbia. BC participants were mostly single (94%), Caucasian (80%), unemployed (86%), and without a high school education (53%). Most (89%) had previously been hospitalized for psychiatric reasons a number of times (5) and from a young age (24 years). Diagnoses of schizophrenia or other psychotic disorders (91%) and a recent history of substance misuse (56%) were common. About 80% had an adult history of criminal charges resulting in either a conviction or a judgement of not criminally responsible due to a mental disorder (NCRMD),4 and 30%, a history of juvenile offending.

Comparing the two groups of patients in the BC sample, the civil (RVH) participants tended to:

  • be younger

  • have been hospitalized from a younger age and more often

  • show more severe psychiatric symptoms, lower levels of functioning and fewer past criminal offences

  • have a shorter in hospital and be less likely to get released under an outpatient commitment order (conditional discharge/ extended leave)

...if those with high negative symptoms attend treatment less often, does it suggest that a lack of engagement in treatment may result in poor outcomes? Or does it instead reflect a clinical judgement by treatment providers that their clients are not in need of more services?

Community outcomes

Even though BC participants stayed in the community for most of the first year after discharge, one in two (52%) were readmitted to hospital at some point, and one in six (15%) to the hospital emergency room. About one in five participants were violent during this year. With a few exceptions, most violent incidents were not serious.

Amongst 248 males with schizophrenia in the international sample:

  • Rates of violence were low in each six ­month period—from 6% to 16% of participants. Civil participants were more likely to engage in violence than were forensic participants, but this group difference disappeared once symptoms of psychosis were statistically controlled for.

  • After taking into account diagnoses of antisocial personality disorder and past substance dependence, severe positive symptoms of psychosis (hallucinations and delusions) increased the likelihood of violence. Neither depot (i.e., injected) medications nor outpatient commitment orders (i.e., extended leave or conditional discharge)— both presumed to improve treatment compliance—dampened this relationship.

  • A past diagnosis of conduct disorder (CD) was associated with substance misuse, earlier onset of illness, and length of time spent in hospital, and, taking these into account, CD remained an important predictor of violence.

  • Amongst 98 BC males with 12 months of follow-­up, those with recent substance misuse were four times more likely to be violent in the first year than were those without recent misuse.

Despite the fact that delays in the criminal justice system have resulted in incomplete criminal history data, thus far, about 7% of the BC sample has been charged and either convicted or found NCRMD in the follow-­up period.

Service Use

In order to properly understand the factors that influence violence and crime, or indeed any human behaviour, we must look beyond the factors that lie within the individual. Amongst people who are living in the community, we must attempt to understand what in the community is contributing to these behaviours.

One important aspect of community living for people with an SMI is the use of mental health services. Recent studies have suggested that most people with a diagnosable mental illness do not seek help, and that certain features (e.g., gender, age, diagnosis) influence service use.7 This suggests that not all those who might benefit from services are actually getting them.

Among BC participants in this study, the use of mental health services was high—all were seen by a mental health professional and most (77%) attended services twice per week or more. However, there are indications of gaps in service, as suggested by the following:

  • Although both groups showed similar rates of service use generally, the forensic outpatients were more likely than the civil outpatients to attend group therapy and to use psychologists’ services.

  • Those who used services most intensely were likely to be less educated, unemployed, with high positive symptoms of psychosis (e.g., delusions) and low negative symptoms (e.g., withdrawn), suggesting the possibility that those with more education and employment, and those with higher negative symptoms, may not be obtaining needed services.

  • Those with recent substance misuse were eight times more likely to attend self­ help groups—suggesting a willingness to address their substance use—and yet they were six times more likely to visit hospital emergency rooms—suggesting poor outcomes in these individuals despite attending treatment.

About this study

The Comparative Study of the Prevention of Crime and Violence by Mentally Ill Persons is an international research project on the community management of risk for crime and violence among discharged civil and forensic psychiatric patients. It took place in Canada, Finland, Germany and Sweden between 1998 and 2005. The international project was headed by Dr. Sheilagh Hodgins, a professor and chair of Forensic Mental Health Sciences at the University of London (England), and was funded by the European Economic Community’s Biomedical II grant program. In Canada, patients were recruited from the Forensic Psychiatric Hospital (FPH) and Riverview Hospital (RVH), both provincial psychiatric hospitals in British Columbia. The BC project site was headed by Dr. Stephen Hart of Simon Fraser University. BC site funding was generously provided by Riverview Hospital, the Forensic Psychiatric Services Commission, and Simon Fraser University’s Mental Health, Law, and Policy Institute.

Next Steps

The research team aims to transfer knowledge gained from this study to mental health policy and service provision for people afflicted with an SMI. Future analyses are needed to better understand gaps in service and unmet need. For example, if those with high negative symptoms attend treatment less often, does it suggest that a lack of engagement in treatment may result in poor outcomes? Or does it instead reflect a clinical judgement by treatment providers that their clients are not in need of more services? In order to tease apart these relationships, we need to take into account outcomes (e.g., violence), as well as treatment non­compliance. A better understanding of gaps in service within certain subgroups of people will provide useful information for effective discharge planning and for community based service provision that is tailored to meet the needs of all consumers.

Finally, while it is important to establish what factors predict outcomes such as violence and crime in this population, future efforts need also to examine factors that 1) protect people from such outcomes, and 2) contribute to positive outcomes in spite the challenges of living with an SMI.

About the Author

Deborah works with BC Mental Health and Addiction Services as Manager of Research at the Riverview and Forensic Psychiatric hospitals. A mental health researcher for nearly 15 years, her interests include the influence of community factors on outcomes in people with serious mental illnesses, mental illness and violence, and substance misuse.
For further information about this project, contact Deborah at 604-524-7301 or [email protected]

  1. Brennan, A., Mednick, S. & Hodgins, S. (2000). Major mental disorders and criminal violence in a Danish birth Cohort. Archives of General Psychiatry, 57, 494-500.

  2. Teplin, L.A. (1994). Psychiatric and substance abuse disorders among male urban jail detainees. American Journal of Public Health, 84(2), 290-293.

  3. Hodgins, S., Tengstrom, A., Osterman, R. et al. (in press). A multi-site study of community treatment programs for mentally ill offenders: Design, measures, and the forensic sample. Criminal Justice and Behavior.

  4. This number is high because half of the BC sample was recruited from the Forensic Psychiatric Hospital, and all of these 60 patients were in hospital as a result of having been found NCRMD for a criminal offence. Another 36 civil patients (60% of this group) also had a criminal record.

  5. Hodgins, S., Tiihonen, J. & Ross, D. (2005). The consequences of conduct disorder for males who develop schizophrenia: Associations with criminality, aggressive behavior, substance use, and psychiatric services. Schizophrenia Research, 78(2-3), 323-335.

  6. Ross, D., Wayte, T., Vincent, G. et al. (2005, November 28-29). A comparison of treatments and services used by civil and forensic psychiatric patients following release from hospital: The BC Aftercare Project. Poster presented at the Mental Health Research Showcase, Banff, AB.

  7. Vasiliadis, H., Lesage, A., Adair, C. et al. (2005). Service use for mental health reasons: Cross-provincial differences of rates, determinants, and equity of access. Canadian Journal of Psychiatry, 50(10), 614-619.

  8. Positive symptoms are characterized by an increase or distortion in some normal function or by experiencing something unusual (e.g., hallucination or delusion). Negative symptoms are characterized by a decrease in, or loss of, some ‘normal’ function or an individual’s normal level of functioning (e.g., withdrawing socially). These terms are used most often in reference to psychosis and schizophrenia, but can also be used to describe depression or dementia. See the PANSS Institute website at for more information.

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