Mental Health Center

Mental Illness and Violence: A Link?

Mental Illness & Violence: Results continued...

When he looked at those with schizophrenia, 5.15% reported violent behavior in the time period between the interviews. But when a person with schizophrenia also had substance abuse or dependence problems, 12.66% reported violent behavior in the time between the interviews.

The highest risk for violence was found in those who had mental illness, a substance abuse problem, and a history of violence. These participants had 10 times the risk of violence than those who only had mental illness.

Other factors that predicted violent behavior included a history of juvenile detention or physical abuse, having seen parental fighting, a recent divorce, unemployment, or being victimized themselves. Being younger, male, and low-income also boosted the chance of violence.

"There is a relationship [between mental illness and violence] but it's much weaker than most people think," he tells WebMD.

"I think a lot of people think mental illness is the usual cause if not the foremost cause of violence," Elbogen says, citing a survey in which 75% of respondents said they considered people with mental illness as dangerous.

But his study concludes that “the findings say mental illness is relevant and you can see that throughout the data. But it's not really one of the foremost causes of violent behavior [by itself] in our society."

Mental Illness & Violence: Second Opinions

Experts who reviewed the paper for WebMD say they hope the new research may change mistaken perceptions toward those who are mentally ill.

"Having a severe mental illness alone doesn't predict anything," as far as violence, says Philip Muskin, MD, professor of clinical psychiatry at Columbia University in New York. The new results, he says, confirm some other studies with similar results.

For those affected by the severe mental illnesses evaluated in the study, Muskin says, "You are no more at risk for committing a violent act than anyone in the population."

Paul Appelbaum, MD, former president of the American Psychiatric Association and a professor of psychiatry at Columbia University, says, "If you take the body of data as a whole, I think what everyone would agree with is, if there is an impact of mental illness on violent behavior it is not very great. And there is no question that the overall contribution of people with serious mental illness to violence in our society as a whole is quite small."