(Reuters Health) - Having a mental illness makes people more vulnerable to becoming the victims of a crime, a recent analysis suggests.

Based on nationwide data from more than 2 million people in Denmark, researchers found that in the 10 years following a diagnosis with any psychiatric disorder, a man’s risk of being the victim of a crime that was reported to police rose by 50 percent. For women, the risk went up by 64 percent compared to women without mental illnesses.

The greatest increased danger was from violent crime: men’s risk of being a victim rose by 76 percent while women’s went up nearly three-fold, the study team reports in JAMA Psychiatry.

The strongest links between mental illness and crime victimization were among people diagnosed with substance abuse disorders and personality disorders, the study team found.

“We hope that the study findings will highlight the importance of the risk of being subjected to crime and violence that people with mental illnesses right across the diagnostic spectrum face,” said lead author Kimberlie Dean, associate professor and chair of forensic mental health at the University of New South Wales in Matraville, Australia.

“We also hope it will motivate more research to improve our understanding of the risk and how to combat it and (help) towards re-balancing public perceptions about mental illness,” she told Reuters Health in an email.

In the wake of recent mass shootings, the public perception has been that the perpetrators of these shootings have been people with mental illness, Dean said, and researchers hope to change that stereotype.

“This study confirms what we’ve known for a long time, which is that people with mental illness are more likely to be victims, not perpetrators of crime. Perpetrators choose victims who seem powerless and helpless,” said Dr. Renee Binder, a professor of psychiatry and director of the Psychiatry and the Law program at the University of California, San Francisco Medical School.

“I think the study rings true in the U.S., too,” Binder, who wasn’t involved in the research, said in a telephone interview.

Dean and her colleagues examined data on 2,058,083 individuals born in Denmark between 1965 and 1998. They searched Danish psychiatric registries, including hospital admissions and outpatient treatment, as well as a national police database that codes crimes into categories such as thefts, simple violence, threats, robberies and severe violence.

The researchers followed the group through the end of 2013, matching individuals with new diagnoses of a psychiatric disorder and any involvement in crime thereafter.

Overall, 234,000 people with no mental illness diagnosis were crime victims, which works out to a rate of about 12 incidents per 1,000 people per year. Among people with a diagnosed mental illness, 31,237 were crime victims, or nearly 22 per 1,000 per year.

Dean said the notable gender gap in risk for victimization among people with psychiatric disorders is consistent with previous smaller studies.

When the researchers accounted for some victims also having been involved in crimes as a perpetrator, the risk of victimization associated with having a mental illness was somewhat reduced, primarily for people with substance abuse disorders.

Some of the increased risk of victimization for people with substance abuse disorders and personality disorders might be due to these individuals’ greater willingness to take risks, Dean said. Individuals with personality disorders also often have difficulties in establishing and maintaining positive relationships with others.

Among the study’s limitations is that it is based on registry data and was not designed to prove if, or how, a mental illness might increase the risk of being a crime victim.

“(The) notion that mentally ill people pose a danger to others appears to be encrusted like a barnacle on the concept of mental illness submerged in the public mind,” writes Jeffrey Swanson, a professor of psychiatry and behavioral sciences at Duke University School of Medicine in Durham, North Carolina, in an accompanying editorial.

“If you look at a description of mass shooters you’ll get a picture of a young man who is isolated and alienated and emotionally disturbed and has access to firearms. But this description matches thousands of others who are never going to do this,” Swanson told Reuters Health in a telephone interview.

SOURCE: bit.ly/2LfDaR7 and bit.ly/2Jbs4vB JAMA Psychiatry, online May 23, 2018.