Mental Illness and Violence

It is a common misconception that those with mental illness are often violent. In the media, for example, violent crimes are often blamed on mental illness, and studies show that people believe those living with psychiatric disorders — like schizophrenia — are more likely to commit violent acts.1

The problem with these beliefs is that they are difficult to verify. Mental illness is often blamed for acts of violence, but this accusation ignores other issues that often lead to violent behavior, including upbringing, environment, socioeconomic status, and substance abuse. And it’s important to remember that correlation isn’t causation; even when there appears to be a relationship between mental illness and violent acts, that doesn’t mean the illness is the underlying cause of the violence.

"Mental illness" is a blanket term encompassing numerous conditions, and people tend to paint in alarmingly broad strokes when they suggest a relationship between “mental illness” and violence. It’s also challenging to define violence, as many definitions and types of it exist. In essence, we can’t conclude that having a mental health disorder makes someone more likely to commit violence. So, until researchers determine the relationship, we can look at the rates of mental illness and how they relate to violent acts to understand better what causes violence, how to respond to it, and, perhaps, how to prevent it.

This guide provides research and resources about the links between mental illness and violence. Keep reading to find out what we already know and what still needs to be determined about this fraught topic.

Just about everyone experiences mental health issues from time to time, but about 19% of adults in the United States live with a mental illness. This term is defined as a health condition that alters your mood, behavior, or ways of thinking and may affect your ability to function well in certain situations, including work or school. Mental illness is diagnosable by a medical professional and treatable, usually with a combination of medication, therapy, and lifestyle changes.2

Examples of common mental illnesses are:3 4

• Depression
• Anxiety
• Neurodevelopmental disorders (ADHD, ASD)
• Bipolar disorder
• Obsessive-compulsive disorder
• Post-traumatic stress disorder
• Psychosis
• Schizophrenia
• Eating disorders
• Substance use disorders

There are many ways to identify if you or a loved one is living with a mental illness. First, their mental health concern is not temporary but lingers and impacts their relationships and well-being. People with mental illnesses may also withdraw from everyday activities, show aggression or irritability, and have extreme changes in mood or emotions. Other signs of mental illness include:3

• Significant changes to diet or sex drive
• Hallucinations, paranoia, or delusions
• Extreme fatigue or stress
• Insomnia
• Drug or alcohol abuse
• Confusion, excessive worry, or intense guilt
• Lack of focus
• Depression
• Suicidal thoughts

Theories abound as to what causes and exacerbates mental illness. However, it’s unlikely that one single variable causes these conditions. Here are a few factors that may contribute to mental illness development:4

• Genetics
• Upbringing and environment
• Lifestyle choices
• Stress
• Trauma
• Biochemical processes
• Brain structure

While this may seem like a simple question with a simple answer, there are many definitions and designations around what is considered a violent act. The World Health Organization defines violence as “the intentional use of physical force or power, threatened or actual, against oneself, another person, or against a group or community, that either result in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment or deprivation.”5

This definition reveals a few things:

1. Violence is intentional. This discounts aggressive acts that accidentally or unintentionally cause harm.
2. Violence is physical or emotional. Something may cause bodily or psychological harm to be considered violent.
3. Threats are a form of violence. Someone doesn’t need to carry through with an action for it to be considered violent.
4. Victims of violence are diverse. You can commit violence against yourself or others, including large groups or whole communities. Anyone can be at risk.
5. Neglect is violence. This means that depriving someone of something they need, like food, water, or shelter, is a violent act.
6. Violence may result in death or injury. While this may be the common conception of the result of violence, it is not the only result.

Experts put types of violence into a few categories. Violence can be physical, sexual, or psychological and may be self-directed, interpersonal, or collective. People exposed to violence, especially at a young age, become predisposed to many physical and mental health disorders, including:6

• PTSD
• Depression
• Anxiety
• Substance use disorders
• Chronic pain
• Diabetes
• Heart disease

The connections between mental illness and violence are not well defined, and there are many contributing factors when considering how violent (or non-violent) people with mental illnesses can be. The common conception is that those with mental illnesses are more likely to be violent than those without mental illnesses, but research shows that this is only marginally true.

In a 2011 study, researchers discovered that in a representative sample of about 35,000 people, 2.9% of people with a serious mental illness committed a violent act during the course of the study compared to 0.8% of people without a mental illness. While this statistic shows that those with mental illnesses were more violent than those without them, it also reveals that 97.1% of people with mental illnesses were non-violent.7

Another example is The MacArthur Violence Risk Assessment Study — a groundbreaking study into the connections between mental illness and violence conducted between 1992-1995 and revisited by scholars in 2008 — which revealed that many factors predisposed those with mental illnesses to commit violent acts. They included:8

• Hallucinations
• Psychopathy
• History of violence
• Childhood physical abuse
• A paternal figure who abused substances
• Antisocial behavior
• Typical signs of anger (according to psychological tests)

All but two of these factors may predispose anyone to acts of violence, whether they exhibited signs of a mental illness or not. Hallucinations and psychopathy (defined as “lack of empathy, poor impulse control, and antisocial deviance”) may appear in people with mental illnesses.8 Still, the other factors in the list could impact just about anyone.

Other factors that researchers have discovered may also heighten the likelihood of violence for someone with a mental illness:8

• A co-occurring substance abuse disorder
• Unemployment
• Living in a high-crime area
• Low education level
• Stress

In essence, research shows that those with mental illness may be somewhat more likely to commit violence than people in the general population. Still, the overwhelming majority of people with mental illness are non-violent. And the same characteristics that may predispose anyone to violence may also predispose those living with mental illness to violence.

Another common conception is that instances of mass violence (such as school shootings or other forms of community gun violence) are only perpetrated by people with mental illnesses. Research reveals that this is not the case and is, instead, a red herring sometimes perpetuated by the news media. In fact, people with mental illness are responsible for less than 1% of all gun-related homicides that occur yearly in the U.S.9

Victimization

Conversely, research confirms that people with mental illness, especially those with severe mental illness, are more likely to become victims of violence than those without a mental illness. According to one study, those with mental illness were ten times more likely to be violence victims than the general population. Here are some other stats about victimization:

• One study on community violence found that, in the previous six months, 23.9% of people with mental illness had committed a violent act, while 30.9% had been victims of violence.
• During the same period, 2.3% of people living with schizophrenia had been charged with violent acts, while 34% reported being victims of violent crime.
• Another study revealed that incarcerated men and women with mental illness were 1.6 times and 1.7 times more likely, respectively, to be victims of physical violence by other incarcerated people.9

Here are some facts and statistics that can help us better understand the connections between mental illness and violence.

• In the U.S., one in 20 adults experiences serious mental illness (SMI) every year.
• Each year, one in six children and teens in the U.S. aged 6-17 experience a mental health disorder.
• One-half of life-long mental illnesses begin by age 14, and 75% start by age 24.4
• In the U.S., 20% of children experience some form of maltreatment, including sexual abuse (1%), neglect (4%), physical abuse (9%), and emotional abuse (12%).6
• According to the CDC, 49,000 people died in the U.S. by gun violence in 2021.10 Every hour, more than seven people die a violent death in the U.S.; in 2019, more than 47,500 people died by suicide.11
• A Swedish survey revealed that, out of 8,003 people with schizophrenia, 13.2% committed a violent crime, while only 5.3% of the general population did the same. Researchers attributed the increase to abuse of alcohol or drugs.
• In a 2015 summary of studies, researchers found that men with schizophrenia are 3-5 times more likely to commit a violent act than men without mental illness. For women, the likelihood increases to 4-13 times.
• Prescription medication may reduce violent tendencies, with one survey showing a 45% decrease in violent crime for patients taking antipsychotics and a 24% decrease for those taking mood stabilizers.
• A 2013 meta-analysis that included 45,533 people with schizophrenia and other forms of psychosis showed that violent behavior results more frequently when patients do not take prescribed medication or participate in therapy. Drug and alcohol use also increased the likelihood of violence.12

Common conceptions of people with mental illness link them to violent acts. This further drives the stigma attached to mental illness and can lead to people not seeking help, hiding a diagnosis, or refusing treatment. When someone reveals a diagnosis, further discrimination may occur because of this conflation of mental illness with aggression and violence.13

But where does this concept come from? Scientific research shows that those with a mental illness are not overwhelmingly more violent than those without mental illnesses, that the vast majority of people with mental illnesses are non-violent, and that the majority of people who commit violent crimes do not live with mental illness. But this perception of people with mental illness as more violent persists and is culturally reinforced.

Experts state that the mass media, particularly the depiction of those with mental illness on television, has a lasting impact on public perception. One study looked at 400 news stories about mental illness across 19 years and discovered that violence was mentioned more than any other topic, with 55% of stories discussing it.14

Another study revealed that “media representations of mental illness are so powerful that they can override people’s personal experiences concerning how they view mental illness.”15 In other words, even if you have personal experience with a person with mental illness, you may be more likely to believe what the media tells you about mental illness than you are to believe your own experiences.

In addition, some depictions of mental illness in the media lead people to believe that those living with mental illness are:15

• Separate from society
• Unemployed
• Unhoused
• Friendless
• Without family
• The “other”

These depictions can dehumanize those with mental illnesses and convince others that they are more likely to commit crimes or be violent.

Mental illness is also often blamed for incidences of violence, like mass shootings or other high-profile crimes. According to researchers, there are usually four assumptions about mental illness that pervade news stories and popular discourse after a mass shooting. They are:16

1. Mental illness leads to gun violence.
2. A diagnosis of a mental illness can predict gun crime.
3. Mass shootings tell us to be afraid of loners with mental illnesses.
4. Gun control laws won’t stop another mass shooting from happening.

While some of these assumptions may be true in specific contexts, they reveal stereotypes that pervade modern conceptions of mental illness — that it is indelibly linked to violence and should be feared. These perceptions perpetuate stigma around mental illness and point conversations about gun control to the individual instead of systemic change.

Certain factors make someone more likely to commit violence. These include life choices, history, and societal factors. Having a mental illness is not a surefire predictor of violence, but some issues that co-occur with mental illness may help us determine who is more at risk.

According to experts, here are some predictors of violent behavior:

The best way to prevent violent behavior for those living with mental illness is to provide treatment for their mental illness and any co-occurring issues, like a substance use disorder. Without treatment, those with mental illnesses are more likely to commit violence.

The most effective treatments are long-term, personalized to the patient’s needs, and include various modalities, like medication, talk therapy, and conflict management. Unfortunately, many people with mental illness do not receive the varied care they need because of cost, lack of health insurance, or a reduction in treatment-seeking due to stigma.

The CDC recommends many ways to prevent violence for the general population, including their recommendations for preventing:19

• Adverse childhood experiences (ACEs)
• Child abuse and neglect
• Child sexual abuse
• Community violence
• Elder abuse
• Firearm violence
• Intimate partner violence
• Sexual violence
• Youth violence

There have been dozens of studies performed and think pieces written about the connections between mental illness and violence. In this section, we provide some resources we believe are valuable for those living with mental illness or caring for someone with a mental illness. This is not an exhaustive list, but we hope it includes some valuable insights.

• 988 Suicide & Crisis Lifeline
• Addressing Misconceptions about Mental Health and Violence
• CDC’s Violence Prevention Homepage
• Center for the Study and Prevention of Violence
• Getting Help for Mental Illness
• Guide to Finding the Best Online Psychiatrist
• Mental Health Services: Aggression and Violence
• Overcoming the Stigma of Mental Illness
• Violence and Mental Health: Opportunities for Prevention and Early Detection
• Violence Prevention Resources