People with mental illness account for only 4 percent of crime overall. But, when you look at aggression and violence against family members, that percentage increases to between 10 and 12 percent. When examining violent incidents against strangers, such as mass shootings, the rate rises to 20 percent.

While people with mental illness are not inherently violent, they can become violent under certain circumstances, typically when symptoms are not being treated, or when someone is using alcohol and other drugs that inflame their symptoms.

There are many myths about violence and mental illness, which is why I recently interviewed for the Healthy Minds public television series, two experts Lloyd Sederer, M.D., Medical Director, NY State Office of Mental Health, and Jeffrey Lieberman, M.D., Professor and Chairman, Department of Psychiatry, Columbia University, to explore the relationship between mental illness and violence, and how science and public perception differ.

In part one of this series, Sederer talked about the profiles of people with mental illness who are at risk of committing violent acts and steps that can be taken by family members and loved ones. 

Here, Lieberman discusses the circumstances that can lead to acts of violence by people who are mentally ill and how we can address this public health crisis.

People with psychotic disorders that feature delusional thoughts and hallucinations sometimes feel a false sense of danger where they perceive non-existent threats. People with these disorders may think that others want to hurt them and feel they must protect themselves; in other cases, they may hear voices that tell them what to do. 

Some people who suffer from mood disorders, such as depression or bipolar disorder, may have a distorted view of the world and may believe that death—their own or someone else’s—is the only escape. In the grip of this kind of distortion in perception or judgement, people can commit tragic acts such as murder suicides.

It is important to remember that people who are mentally ill are no more violent than the general public. But, when you look at these very egregious crimes, it is true that the mentally ill are overrepresented. 

The primary reason we keep seeing acts of violence within families, and shocking acts of violence against innocent people in schools, the workplace, shopping malls and clubs, is primarily due to the lack of available mental health care.

We are seeing the manifestation of a mental health policy that has failed and led to a national emergency. In many ways, you can calculate the likelihood of these violent acts like an actuarial table for forensic purposes. If you look at the last incidents of mass criminal acts perpetrated by individuals with mental illness, they all have the same profiles: young males, who are not receiving treatment. If they had received treatment, the likelihood of these events would be have been greatly reduced or eliminated.

If we don’t provide effective mental health care, some very small number of people who go untreated—acting under the influence of symptoms—will commit a violent act that has a huge impact on our national psyche.

In many cases, family members are aware there is a problem and are concerned about an increasingly out-of-control and potentially violent child who needs to be forced into treatment. Unfortunately, when a family member calls a crisis team or the police, the threshold for imposing treatment against someone’s will is too high. There must be proof of imminent danger to one’s safety or others, and often nothing can be done until something happens. We need to empower people to do everything necessary before a tragedy occurs.

Lieberman told me about the tragic case of a young man who went to college—the first in his family to do so—on a football scholarship and dropped out after experiencing psychotic symptoms. He was delusional and thought his family was trying to poison him. When his family contacted a crisis team, they were told that they could take him to an emergency room only if he was suicidal. Since they couldn’t prove that he was, they couldn’t seek treatment. Later that afternoon, the young man stabbed his brother to death.

We see the same problems in the case of homeless people who are clearly mentally ill. Our society’s reluctance to infringe on someone’s civil liberties prevents these people from receiving the treatment they desperately need. But our society has a different standard for treating mental illness as opposed to other medical conditions; when someone is having a heart attack, we treat them even if they are unable to give consent for treatment.

Effective treatment is key. In order to reduce or eliminate the risk of violence committed by people who are at the mercy of impulses beyond their control, we must finally recognize that mental illness is a medical condition and demands treatment like any other physical ailment.

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The Myth of the Violent Mentally Ill, Part Two

Mentally ill people are not inherently violent.

The Myth of the Violent Mentally Ill, Part One

When a mass act of violence occurs, mental illness often becomes top of mind.