Assisted living residents who abuse other residents or staff are likely to have dementia or severe mental illness, afflictions that pose unappreciated risks in facilities occupied by vulnerable elderly adults, a new study reported.

That abuse can include physical, verbal and sexual incidents, according to a study published online in the Journal of Applied Gerontology. Other studies have examined resident aggression in nursing homes, but the authors said that few have explored the problem in assisted living.

“Resident aggression and abuse in assisted living facilities is prevalent and warrants greater attention from policymakers, researchers and long-term care providers,” the researchers said.

The study examined data collected in a 2010 federal survey in which facility administrators were asked about instances of aggressive or threatening behavior by residents in the previous month.

Gilbert Gimm, the study’s lead author and an associate professor in the Department of Health Administration and Policy at George Mason University in Fairfax County, Va., said he was surprised to discover how prevalent resident aggression and abuse was in assisted living. Older residents’ frustration with their declining ability to care for themselves might be a factor.

In a national sample of 6,848 residents at least 65 years old, Gimm and two collaborators found that 7.6 percent of residents had engaged in physical aggression or abuse toward other residents or staff in the month before the survey. Verbal abuse or aggression was shown by 9.5 percent of residents, according to the study.

Of the residents linked to aggression, those with dementia were five times more likely to engage in physical abuse and those with severe mental illness were three times more likely to take part in physical abuse, researchers reported.

Male residents more often engaged in physical abuse than female residents. Residents with severe mental illness were three times as likely to engage in physical abuse, verbal abuse and sexual abuse.

Researchers said their estimates might be low because aggression that happened out of staff members’ sight was not captured in the federal survey.

When assisted living residents are injured, they may be moved to a different location, which can be disruptive for seniors who don’t cope well with transitions, Gimm said.

The study said that increased training is needed for staff and caregivers so they can better detect and manage residents with dementia and mental illness.