People With Mental Illness More Often Crime Victims

More than one-fourth of persons with severe mental illness are victims of violent crime in the course of a year, a rate 11 times higher than that of the general population, according to a study by researchers at Northwestern University.

They estimated that nearly 3 million severely mentally ill people are crime victims each year in the United States.

This is the first such study to include a large, random sample of community-living, mentally ill persons and to use the same measures of victimization used by the U.S. Bureau of Justice Statistics, said lead author Linda Teplin, Ph.D., Owen L. Coon Professor of Psychiatry and Behavioral Sciences at the Feinberg School of Medicine of Northwestern University, in the August Archives of General Psychiatry.

Victimization rates vary with the type of violent crime, said the researchers. People with mental illness were eight times more likely to be robbed, 15 times more likely to be assaulted, and 23 times more likely to be raped than was the general population. Theft of property from persons, rare in the general population at 0.2 percent, happens to 21 percent of mentally ill persons, or 140 times as often. Even theft of minor items from victims can increase their anxiety and worsen psychiatric symptoms, the researchers said.

“The direction of causality is the reverse of common belief: persons who are seriously mentally ill are far more likely to be the victims of violence than its initiators,” said Leon Eisenberg, M.D., professor emeritus of social medicine and health policy at Harvard Medical School, in an accompanying editorial. “The evidence produced by Linda Teplin et al. settles the matter beyond question.”

The Northwestern researchers randomly selected 16 sites from a list of 75 agencies in Chicago that offer outpatient, day, and residential treatment to people with mental illness. Participants were then randomly selected from these sites and stratified by sex, race/ethnicity, and age. To qualify for inclusion, patients had to have taken psychiatric medications for the previous two years or have been hospitalized for psychiatric reasons at some time in their lives.

In all, 936 patients with psychosis or major affective disorder completed the survey; 52 percent were male, and about 35 percent were African American, 29 percent Hispanic, and 34 percent non-Hispanic white.

Participants were interviewed using the Composite International Diagnostic Interview version 2.1, supplemented by diagnosis records. They also answered the National Crime Victimization Survey (NCVS), which is used by the Department of Justice to survey 43,000 U.S. households each year on crime victimization.

“The use of the NCVS makes a great deal of sense,” said Bruce Link, Ph.D., a professor of epidemiology at Columbia University, in an interview with Psychiatric News.

Future research on mentally ill populations should also make use of the NCVS questionnaire to provide findings comparable to national data, said Teplin. Investigators might ask about diagnosis, treatment, and socioeconomic issues, as well, she noted.

While 25 percent of their subjects in this study were victims of violent crime, 28 percent were victims of property crime, which is about four times higher than the national rate. Property crimes include household theft, motor vehicle theft, and property theft.

“These prevalence ratios are lower than the ratios for other crimes because property crimes are common in the general population,” wrote Teplin.

Incidence—the number of crimes per 1,000 persons per year—was also higher among people with serious mental illness.

For every 1,000 people in the overall NCVS survey, there were about 40 crimes. However, among those with mental illness, there were 168 such incidents.

“Prevalence and incidence were high among all racial/ethnic groups, probably because poverty—highly correlated with victimization—is common in our sample, irrespective of race/ethnicity,” wrote Teplin. Prevalence ratios were higher than incidence ratios, indicating that incidence was not driven by a few individuals being victimized repeatedly. The relative difference between the Chicago sample and the NCVS national survey may even be greater, since the latter would include a sample of the mentally ill population.

“Symptoms associated with SMI [serious mental illness], such as impaired reality testing, disorganized thought processes, impulsivity, and poor planning and problem solving, can compromise one's ability to perceive risks and protect oneself,” she said.

Many severely mentally ill persons also contend with poor social relationships, substance abuse, homelessness, and poverty, which may also contribute to victimization.

“The results clearly say something about where people with mental illnesses end up in our society,” said Link. “Halfway houses and group homes tend to be located in areas without the political clout to keep them out.”

When most people associate crime and mental illness, they usually think of people with mental illness as perpetrators, not victims, said Link. Yet previous research shows that only discharged psychiatric patients who also abuse substances commit violent acts at rates greater than their neighbors.

“More studies like Teplin's can help, but changing attitudes on the basis of data is difficult,” Eisenberg told Psychiatric News.“ It's a tough problem and requires everyone's engagement.”

An abstract of “Crime Victimization in Adults With Severe Mental Illness: Comparison With the National Crime Victimization Survey” is posted at<http://archpsyc.ama-assn.org/cgi/content/abstract/62/8/911>.▪

Arch Gen Psychiatry 2005 62 911