Violence and Mental Illness

Primer

The relationship between violence and mental illness is a challenging issue that clinicians face. The association between the two is commonly linked together in popular media and society, resulting in an exaggerated and misunderstood perception of mental illness. Clinicians are often asked to assess the risk that a patient could pose to the public, while also being asked by society/law to keep an individual's personal liberties in mind.

Are the mentally ill more violent on a population level?

Large scale meta-analyses have shown that even categorizing individuals at “high risk” of violence had very little effects of predicting violence on a population level. One study demonstrated that to prevent one homicide, 35,000 “high-risk” schizophrenia patients would need to be detained.[1]

Who is at higher risk?

Three factors are implicated in those who have a higher risk of violence compared with the general population: (1) severe mental illness, (2) substance abuse and/or dependence, and (3) a past history of violence. Individuals with all of these risk factors have a distinctly higher than average risk of violence (severe mental illness alone does not predict risk of violence).[2] These individuals should have a more structured violence risk assessment done, such as with the HCR-20. In acute psychiatric settings, young age, male sex, history of psychiatric illness, comorbid substance abuse and positive symptoms of a psychotic disorder have also been shown to be predictors of violent behaviour.[3]

Approach

See Rueve, M. E., & Welton, R. S. (2008). Violence and mental illness. Psychiatry (Edgmont), 5(5), 34. for an excellent review of approach to violence/agitation in mental illness.

DASA

The Dynamic Appraisal of Situational Aggression (DASA) is a brief, 7-item scoring instrument to aid health care professionals in identifying patients with an increased risk of violence, in order to enable focused preventative interventions to reduce risk of imminent violence.[4]

Scales

Scales for Violence Assessment

Name Rater Description Download
Historical Clinical Risk Management-20 (HCR-20) Clinician 20-item, clinician-rated scale Download HCR-20 (1 page), (2 page)
Classification of Violence Risk (COVR) Clinician/Patient An interactive software program that estimates the risk that a psychiatric inpatient will be violent to others. The software leads the clinician through a chart review and a brief interview with the patient. Not available

HCR-20

The Historical Clinical Risk Management-20 (HCR-20), is a validated violence risk assessment tool. It is the most commonly violence risk assessment instrument.[5]

Mass Violence

Resources

For Patients

For Providers

Articles
Research

References

1) Large, M. M., Ryan, C. J., Singh, S. P., Paton, M. B., & Nielssen, O. B. (2011). The predictive value of risk categorization in schizophrenia. Harvard review of psychiatry, 19(1), 25-33.
2) Elbogen, E. B., & Johnson, S. C. (2009). The intricate link between violence and mental disorder: results from the National Epidemiologic Survey on Alcohol and Related Conditions. Archives of general Psychiatry, 66(2), 152-161.
3) Varshney, M., Mahapatra, A., Krishnan, V., Gupta, R., & Deb, K. S. (2016). Violence and mental illness: what is the true story?. J Epidemiol Community Health, 70(3), 223-225.
4) Lantta, T., Kontio, R., Daffern, M., Adams, C. E., & Välimäki, M. (2016). Using the Dynamic Appraisal of situational Aggression with mental health inpatients: a feasibility study. Patient preference and adherence, 10, 691.
5) Douglas, K. S., Hart, S. D., Webster, C. D., & Belfrage, H. (2013). HCR-20V3: Assessing risk of violence – User guide. Burnaby, Canada: Mental Health, Law, and Policy Institute, Simon Fraser University.