New research shows that almost one-third of adults with mental illness are likely to be victims of violence within a six-month period, and that adults with mental illness who commit violence are most likely to do so in residential settings. The study also finds a strong correlation between being a victim of violence and committing a violent act.

The work was done by researchers at North Carolina State University; RTI International; the University of California, Davis; Simon Fraser University; and Duke University.

"We hear about the link between violence and mental illness in the news, and we wanted to look not only at the notion that the mentally ill are a danger to others, but the possibility that they are also in danger," says Dr. Sarah Desmarais, an assistant professor of psychology at NC State and lead author of a paper describing the work.

The researchers compiled a database of 4,480 mentally ill adults who had answered questions about both committing violence and being victims of violence in the previous six months. The database drew from five earlier studies that focused on issues ranging from antipsychotic medications to treatment approaches. Those studies had different research goals, but all asked identical questions related to violence and victimization.

The researchers found that 23.9 percent of the study participants had committed a violent act within the previous six months. The majority of those acts - 63.5 percent - were committed in residential settings, not in public. Only 2.6 percent of the violent acts were committed in school or workplace settings.

The researchers found that a significantly higher percentage of participants - 30.9 percent - had been victims of violence in the same time period. And of those who said they were victimized, 43.7 percent said they'd been victimized on multiple occasions.

"We also found that participants who had been victims of violence were 11 times more likely to commit violence," Desmarais says. "This highlights the need for more robust public health interventions that are focused on violence. It shouldn't just be about preventing adults with mental illness from committing violent acts, it should also be about protecting those at risk of being victimized.

"For one thing, it's the right thing to do," Desmarais adds. "In addition, while correlation is not necessarily causation, preventing violence against the mentally ill may drive down instances of violence committed by the mentally ill."