A Destructive Mythology: Exploring the Link Between Mental Illness and Violence

Despite the popular belief that those who experience mental illness are at heightened risk of committing violent acts, a “definitive causal relationship between violence and mental illnesses has not been established.” Older studies claiming to have found a link between the two have often suffered from major methodological flaws, including inconsistent definitions of mental illness and inadequate control of variables contributing to violent behavior. More methodologically sound research has emerged in recent years to correct for these flaws. One such study, the MacArthur Violence Risk Assessment Study, found that:

31% of people who had both a substance abuse disorder and a psychiatric disorder (a “dual diagnosis”) committed at least one act of violence in a year, compared with 18% of people with a psychiatric disorder alone. But when the investigators probed further, comparing rates of violence in one area in Pittsburgh in order to control for environmental factors as well as substance use, they found no significant difference in the rates of violence among people with mental illness and other people living in the same neighborhood. In other words, after controlling for substance use, rates of violence reported in the study may reflect factors common to a particular neighborhood rather than the symptoms of a psychiatric disorder.

Data from the MacArthur study reveals that even specific mental health disorder symptoms commonly associated with higher risk of violence, such as delusions, in fact did not augment propensity for violent acts when other phenomena related to violent crime were accounted for.

Another major design flaw in many studies is the failure to distinguish between correlative and causative relationships between mental illness and violence, and the assumption that the presence of a mental illness has a direct relationship to the crime committed. Research that does distinguish between correlation and causation has overwhelmingly found that mental health disorders play a very small role in violent crime. For example, a study on prisoners in an Alberta detention center found “while 19% of persons charged with committing a violent crime had a mental disorder, only 3% of total charges related to violence could be attributed to the mental illness itself.” Additionally, the vast majority of crimes are committed by people who do not have a mental illness; psychiatrist Paul Applebaum found that only 3-5% of crimes in the United States are perpetrated by those with a mental health disorder and people with psychiatric illnesses are significantly less likely to commit gun crimes than the general population. According to the National Center for Health Statistics, fewer than 5% of gun-related homicides are committed by people with a mental illness, starkly contradicting popular myths.

Although no compelling evidence exists that mental health disorders are the primary or even a significant cause of violent crime, public speculation and stigmatization continue, adding to the vulnerability of people suffering from mental health disorders. Myths about the propensity of violence in those living with mental illness have very real and damaging effects, creating barriers to housing, education, employment, medical care, and meaningful interpersonal relationships as the result of both overt discrimination and internalized shame.

The cultural spectre of danger and stigma surrounding mental illness also increases the likelihood that those affected will become the victims of violent crime; as research by Vanderbilt University’s Jonathan Metzl and Ken MacLeish reveals, “the mentally ill are 60 to 120% more likely than the average person to be the victimsof violent crime rather than the perpetrators.” As a result, people may be reluctant to disclose their struggles with mental illness, increasing their isolation and disenfranchisement, impeding recovery, and compromising their ability to live a fulfilling and productive life. And this contributes to the one type of violence that is indeed associated with mental illness: “violence against oneself” in the form of both self-harm and suicide.

Simplistic and alarmist public discourse also fails to recognize the rich, multifaceted, and heterogeneous experiences of people living with mental health disorders, turning mental illness into a monstrous caricature and erasing the humanity of those affected. Media accounts often flatten “mental illness” into vague and monolithic category, despite the fact that mental illness encompasses a wide range of diagnoses with drastically divergent and variable symptomatologies. Discussions of mental health disorders that do not differentiate amongst kind and severity of illnesses or acknowledge the extraordinarily diverse range of presentations within each diagnosis ignore the unique lived experiences and needs of people living with mental health disorders. Worse still, by turning people into caricatures defined by an amorphous conceptualization of “mental illness” to which all of your actions are attributed, these discourses serve to silence and deny the agency of those with mental illness. Your thoughts, motivations, beliefs, and actions are no longer regarded as expressions of your authentic self, independent of mental illness, but merely the product of psychiatric dysfunction, rendering you an unreliable and powerless narrator of your own experience. As Arthur Chu writes in a passionate article for Salon, “When you call someone ‘mentally ill’ in this culture it’s a way to admonish people not to listen to them, to ignore anything they say about their own actions and motivations, to give yourself the authority to say you know them better than they know themselves.”