Mental Illness and Violence

Mental Illness Graphic

Does having a mental illness increase a person’s likelihood for violence?

In most cases, it does not. However, the public generally believes that individuals with mental illness are violent. Much of the stigma associated with mental illness may be due to a tendency to correlate mental illness with dangerousness.

Sensationalization in the Media

At times, this perception is further exacerbated by the media, which sensationalizes violent crimes committed by individuals who struggle with mental illness. According to an Opinion Poll in 2018 (National Stigma Studies), 60% of respondents believed that people with schizophrenia were dangerous to others.

This bias driven by society contributes to the stigma faced by those with a psychiatric diagnosis, which in turn contributes to non-disclosure of the mental illness and a reduction in seeking out mental health treatment.

Those individuals with mental illness make up a small proportion of violent offenders. Only approximately three to five percent of violence is due to mental illness.

In fact, individuals with mental illness are more likely to engage in self-injurious towards themselves than to engage in violence toward others.

What is the definition of violence?


  • The use of physical force so as to injure, abuse, damage or destroy

California Penal Code 1601 (a)

  • Any felony involving death, great bodily injury, or an act which poses a serious threat of bodily harm to another person

E.g., murder, mayhem, carjacking, certain sex offenses

The Historical Clinical Risk Management-20-Verison 3 (HCR-20-V3; Risk assessment)

  • The HCR-20-V3 is a structured professional judgement measure designed to assess risk for future violence and to inform risk management planning to prevent future violence. The HCR-20-V3 defines violence as:
  • Actual, attempted, or threatened physical harm or another person that is deliberate and nonconsenting

E.g., stalking=violence

E.g., criminal threats=violence

Mental Illness Graphic

Wide Range of Mental Health Conditions

Mental illness is a spectrum, meaning there are a wide ranges of varying mental health conditions, each with different sets of symptoms and severity levels. 

Individuals with serious mental illness generally refers to those with major depressive disorder, bipolar disorder, schizophrenia, and schizoaffective disorder.


Research regarding violence and mental illness shows wide variability; some studies show a clear link between mental illness and violence whereas other studies support the notion that mental illness is not a contribution to risk of violence. As a result, there is considerable controversy in the mental health field regarding how to best interpret the link between mental illness and violence.

A study conducted in 2016 with a community sample of 34, 653 individuals from the National Epidemiologic Survey on Alcohol and Related Conditions, 2.9% of individuals with serious mental illness had committed violent acts between 2 and 4 years following the study’s baseline, compared with 0.8% of individuals with no serious mental illness or substance use disorder.

However, 10% of individuals with both serious mental illness and substance use disorder committed such acts during that time. Another study reviewed United States empirical studies published since 1990 of the commission of violence among individuals with severe mental illness.

Results varied depending on the setting, with the lowest prevalence rates of violence were seen in outpatient settings, where 2.3 to 13% of individuals had engaged in violence in the past six months to three years, compared to the highest rate of engaging in violence which was in acute care settings and involuntarily committed individuals. 

The above research may seem to support the concept that individuals with mental illness pose a danger to society. However, a closer look reveals that the situation is more complex. In the most general sense, “there is a link between mental health and violence.” (Elbogen, 2016). Further Elbogen (2016) stated, “But at the same time, most people with severe mental illness are not violent.”

Predictors of Violent Behavior

Mental illness and violence at times can be connected thorough the accumulation of risk factors.

Some of these risk factors include, past violence, juvenile detention, physical abuse, family history of violence, substance abuse, age, sex, and contextual (recent divorce, unemployment).

One of the most prevalent risk factors is co-occurring substance use.

In fact, for those with mental illness without substance use, the relationship with violence decreased. The Triad of Violence is known as the combination of substance abuse, mental illness, and a history of violence (Fazel 2009).

Mental Illness Graphic

As noted above, there is an assortment of variables that can be assessed as risk factors for violence or put individuals at an increased risk to engage in violent behavior. Historical factors such as an individual’s behavior as a young adolescent (e.g., behavior problems), a history of arrests for violent offenses, or a general history of violence. Also, being a young male increases an individual’s likelihood of engaging in violence toward others.

The MacArthur Violence Risk Assessment Study was conducted between 1992 and 1995, this study is the seminal study on risk of violence in those with mental illness. This study had a sample of  951 psychiatric patients whose ages 18 to 40 after discharge from state and university psychiatric inpatient units in Kansas City, Pittsburgh, and Worcester, Massachusetts.

The purpose of the study was to ascertain the prevalence of community violence in a sample of people discharged from acute psychiatric facilities.

An interesting finding from this study was related to environmental risk factors. To compare the prevalence of violence attributable to the discharged patients, a random community sample was obtained in Pittsburgh, one of the study sites, of individuals living in the same sections of the city as the discharged patients.

Thus, when the study compared discharged psychiatric patients without a substance use disorder to individuals from their same neighborhoods, it was deemed their rates of violence were about the same. Thus, we can draw a conclusion that when an individual’s neighborhood is unsafe, has a lower socioeconomic status, and higher crime rates, violence is an equally likely outcome whether an individual has a mental illness or not.

Which Symptoms May Lead to Violent Behavior?

Mental Illness GraphicAt times, mental health symptoms can spur an individual to engage in aggression or violence. Below are a few examples:

Grandiosity, which is a symptom of the manic and hypomanic phases of bipolar disorder, can play a role in violence and aggression. With grandiosity, an individual has increased or exaggerated sense of self or power, which can affect their ability to empathize with others and may lead them to take advantage of others. Moreover, the high energy that is also seen in mania can lead to violence or aggression. A study conducted by Peterson et al. (2014) showed that of 429 crimes committed by 143 offenders with mental illness, 3% related directly to depression, 4% to psychosis, and 10% bipolar disorder, including impulsivity which is another key symptom in bipolar disorder.

As noted above, The MacArthur Violence Risk Assessment Study looked at the prevalence of community violence in a sample of people discharged from acute psychiatric facilities. Another interesting find in the study was that a clinical symptom of command hallucinations, or auditory hallucinations that instruct an individual to act in specific ways were associated with violent acts among the participants. Moreover, psychopathy (characterized by a lack of empathy, poor impulse control, and antisocial attitudes), also was associated with violent acts among the participants, but psychopathy is not typically considered a serious mental illness.


The relationship between mental illness and violent behavior has serious implications from a public health perspective. A diagnosis alone is never enough to tell you if an individual is likely to be violent or violent again in the future. Instead, a contextual approach is needed that considers symptoms, circumstances, and individual characteristics, among other factors to draw conclusions on an individual’s risk assessment or propensity to engage in further violence.  Overall, individuals with major mental illness are slightly more likely to commit violence than the general population, but per Swanson (2015), if we cured major mental illness, it would only reduce serious violence by 4%. The relationship between violence and mental illness only intersects “at the edges.” Moreover, we need to inquire if we are asking the wrong questions. Are individuals with mental illness more likely to be violent than those without mental illness? According to Douglas, Guy, and Hart (2009), we need to examine which specific symptoms of mental illness within specific situational circumstances, in combination with personal or situational factors are associated with increased or decreased risk of various kinds of violence.


Buchanan  A Risk of violence by psychiatric patients: beyond the “actuarial versus clinical” assessment debate.  Psychiatr Serv2008;59 (2) 184- 190

Choe JY, Teplin LA, Abram KM. Perpetration of violence, violent victimization, and severe mental illness: balancing public health outcomes. Psychiatr Serv 2008;59:153–64. doi:10.1176/ps.2008.59.2.153

Corrigan P. How stigma interferes with mental health care. Am Psychol 2004;58:614–25. doi:10.1037/0003-066X.59.7.614

Elbogen EB, Johnson SC. The intricate link between violence and mental disorder: results from the National Epidemiologic Survey on Alcohol and Related Conditions. Arch Gen Psychiatry 2009;66:152–61. doi:10.1001/archgenpsychiatry.2008.537

Elbogen, E. B., Dennis, P. A., & Johnson, S. C. (2016). Beyond mental illness: Targeting stronger and more direct pathways to violence. Clinical Psychological Science, 4(5), 747–759.

Peterson, J. K., Skeem, J., Kennealy, P., Bray, B., & Zvonkovic, A. (2014). How often and how consistently do symptoms directly precede criminal behavior among offenders with mental illness? Law and Human Behavior, 38(5), 439–449.

Torrey EF, Stanley J, Monahan J, Steadman HJ; MacArthur Study Group. The MacArthur Violence Risk Assessment Study revisited: two views ten years after its initial publication. Psychiatr Serv. 2008 Feb;59(2):147-52. doi: 10.1176/ps.2008.59.2.147. PMID: 18245156.

Van Dorn R, Volavka J, Johnson N. Mental disorder and violence: is there a relationship beyond substance use? Soc Psychiatry Psychiatry Epidemiology 2012;47:487–503. doi:10.1007/s00127-011-0356-x

Varshney M, Mahapatra A, Krishnan V, Gupta R, Deb KS. Violence and mental illness: what is the true story? J Epidemiology Community Health. 2016 Mar;70(3):223-5. doi: 10.1136/jech-2015-205546. Epub 2015 Aug 28. PMID: 26320232; PMCID: PMC4789812.

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